Test Ride of the ZEV Scooters

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PJD
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Sorry about the delay, but here is an account of my test ride of the ZEV models 6100, 7000 and the Trail and Utility 5100. The manufacturers web site is: http://www.zelectricvehicle.com/

The test site was at the Greene County Airport, near Waynesburg, Pennsylvania, a little less than an hour drive south of Pittsburgh. The final assembly is done in a small hanger at this typical sparsely used 3500 foot rural county airport. Upon arrival Darus Zehrbach, ZEV's owner and his helper (don't recall his name) were assembling the battery pack on a 5100 model. The following summarizes my impressions from observing talking to Mr. Zehrbach, observing the scooter being assembled, and the test rides.

Z Electric Vehicle Corporation

ZEV is a small US enterprise based in Morgantown, West Virginia and nearby Waynesburg, Pennsylvania. The principal officer and engineer of the company, Darus Zehrback has a background mostly various aviation-related enterprises including, he said, contract work for US military R&D. I asked him why he decided to get into the electric scooter line of business and the motivations of his buyers so far. He said that it was the low “fuel” cost and reliability of electric-versus IC engine powered cycles that were the main selling points. He elaborated a bit on maintenance costs of motorcycles, claiming that high performance motorcycles typically need valve overhauls every 3000 miles (?). I asked if concern about global warming was a motivation for many buyers, as it was for me whn I bought my e-maxs 5 years ago. Both Darus and his assistant pooh-poohed global warming (“by the time global warming becomes a problem you will be long dead” said his assistant). This seemed odd – an EV manufacturer who is practically a global-warming denialist. But I’m starting to digress. On to the scooters themselves...

Scooter Construction

The ZEV scooters are, externally, a common Chinese-style scooter with electric versions like the E-Fun, X-treme, R Martin and others. Darus said that the controller, motor, BMS and other key components, while made in China, are custom units made to his specifications. He said the frame is entirely his design and built off site (in China?) using jigs be designed and built himself. Final assembly is in the Waynesburg hanger, so the scooters have a US Manufacturer code (1Z9)on the VIN.

The battery pack consists of 40AH Thundersky cells, assembled in 4-cell (12V nominal) sub-packs then wired together. The 5100 I observed had five sub-packs (60V) the 6100 has six sub-packs (72V) and the 7000 has seven sub-packs (28 cells-84 volts). In the case of the 5100 they are mounted, terminal-up, and in a single row in a battery box mounted low in the frame. I assume the higher-voltage models have some of the sub-packs stacked, but overall, the battery packs appeared to be easily accessible for servicing. The BMS utilizes small shunt circuit boards across each cell and a separate logic module. The wiring that I could see was tidy and well secured. All the scooters used the 40AH cells. Only the 5100 trail I test rode used the larger 60AH cells.

Charging is done using an off-board 10 amp charger.

Instrumentation included a voltmeter for the 12 volt accessory system (not a particularly useful thing) a 1-2-3 LCD indicator for the “transmission” (more on that later), and a battery pack state of charge indicator that appeared (from its behavior during the ride) to be just a qualitative high-low voltmeter. So, as a bare minimum, the owner of one of these scooters would need to add a digital batter pack voltmeter (as I did with my E-Maxs) in order to provide even a crude qualitative state-of-charge indication. While technically US-made, the speedo and odo reads in kph/kilometers. The scooters use ordinary mechanical-drive speedometers, while the trail scooter uses an electronic digital speedometer with a magnet and hall pickup on the front wheel. Darus admitted the speedometer indication is probably high, claiming that this is the case in all motorcycles. I had hoped to verify the speed with a GPS, but couldn’t find a suitable attachment point.

Test Rides

The test rides were all limited to near-straight runs up and down the 3500 foot taxiway and slower riding on the ramp area. No rides were allowed on actual roads, due to insurance reasons and also, the demonstrator scooters were not licensed. This was a shame, since there are a lot of hilly and winding roads around the airport. Weather was cloudy, some light wet snow/sleet showers, damp to wet pavement and a temperature of about 2 to 3C. The runway and parallel taxiway is numbered 9/18 (straight east-west) and slopes at about 1% to the east. There was a 15 to occasionally 20 mph (25-32 kph) wind out of the west.

The Model 6100 was tested first. It felt quite light in weight – lighter than even my e-max, although this was probably an illusion of the larger size and lower center of gravity. The front brake emitted an awful grinding noise, as if the brake pads had worn to the point of metal-against metal. I decided to give it a test ride anyway, and reserve any critique of the brakes for the Model 7000. All scooters were given at least two speed-runs in each direction down the taxiway in the wind and slope conditions described above. Results:

6100 (claimed 101-102 kph)
Test:
Downwind/downslope 102 kph
Upwind/upslope 80-82 kph

7000 (claimed 130 kph
Test:
Downwind/downslope 120-125 kph
Upwind/upslope 100-105 kph

Note that these were indicated speeds on the speedometer. If they are typical Chinese scooter speedometers, they may be up to 10% high.

I also test rode the 5100 trail, but relying on memory, I cannot recall what the top speed except that it was indicating just below the claimed speed.

Other general observations and impressions:

- The acceleration of all the models is ample, but not outstanding - a bit better than my upgraded 60 volt E-max from 0 to 60 kph. The speed was still very gradually increasing at the end of the 3500 foot (1.1 km) speed runs.

- The brakes on the 7000 were adequate but basically had that “cheap-Chinese” feel - not entirely smooth and confidence inspiring. Brake effort was higher than it should be, like my e-max gets when the brake pads get worn and glazed, or when a new brake pad set hasn’t broken-in yet.

- I didn’t attempt much in the way of quick turns due to the damp conditions, but both scooters seemed to be a bit slow getting them rolled into turn. Maybe I’m spoiled by my little short wheelbase E-max, but it may be that the low battery pack placement puts the center of gravity too low and makes the scooter “too stable”.

- The throttle action was a bit “twitchy” on the 6100 and unacceptably twitchy on the 7000 where it would jump from off to perhaps 30% power no matter how gradually the throttle was turned, (and no matter what “gear” it was in). This made low speed maneuvering and parking unpleasant. Doing slow figure-8’s could be only done with jerking and lurching. It would be hard to pass the figure-8 test for the state motorcycle license on it without a lot or practice. I commented about this to Darus, suggesting a faulty throttle or controller adjustment, but he just said that it was an unavoidable aspect of “all that power” the scooter has. He said his 1000 cc Kawasaki does the same thing. Yeah, sure.

- The battery pack meter was sagging considerably during the speed runs. The 6100 down to 50% and the 7000 read down near the bottom of the gauge. Darus claimed both scooters were fully charged. This may be due to the voltage sag that Thundersky cells are prone to in cold weather. The 3-year old 40 AH Thundersky cells, with about 12,000 km of use on my e-max, sag down to about 2.8 volts per cell at 95 amps in recent 0 to-3C weather.

- The E-Fun style body of these scooters is not my favorite esthetically, but compared to my little e-max, it was more comfortable and practical. The fairings and even that that little windshield fended off the cold wind quite well and in spite of not being dressed very warmly, I hardly noticed the cold conditions.

The “Transmission”

There was considerable talk about the 3-speed “transmission” in a previous thread. The “transmission” is toggled 1-2-3-2-1 by a button next to the throttle handle (where the start button would be on a gas scooter) and on the 7000 automatically returns to “first gear” if brought to a complete stop. The effect of the “gears” seemed to have a different action on the different scooters. On the 6100, it affected the acceleration moderately and the top speed greatly, perhaps 45 kph in first, 70 in second, and maximum speed in third. On the 7100, it has what seemed to be just a slight effect on either acceleration or speed in either gear. Darus confirmed that the “transmission” is just a controller current and/or voltage limit setting – similar to the “90 second turbo” buttons on the old e-max. I'm feeling charitable, so I won't entirely dismiss this "transmission" as a gimmick. Such measures can be useful in providing the rider with “throttle discipline” for maximizing the range of the battery pack in various riding conditions.

Overall, my impression of these scooters was one of an 80% design in need of a few significant tweaks. Darus said that there have been some improvements - particularly suspension improvements, since they built these demonstrator scooters.

I’m limited in what other comparisons I can make, since my own experience on scooters or motorcycles of any sort is very limited. Ride quality was certainly improved over my e-max, commensurate with the higher speed they could safely go, but they still had much of the same Chinese-quality ride, finish, and component-quality as the E-max.

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Johnny J's picture
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Re: Test Ride of the ZEV Scooters

Thanks for the info, seems like my suspicions regarding the "gears" were right.
It would really be intresting to see how many Amps the 7100 draws at full throttle, I would guess a lot more than 3C on the 40Ah cells... -"Bye-bye Thunder-Sky" ;-)

Regards

Johnny

PJD
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Re: Test Ride of the ZEV Scooters

Johnny,

Actually, according to Darus, all ZEV scooters draw a maximum of less than 100 amps.

However, checking just now, assuming a generous Cd of .7 and a frontal area of 8 square feet (rider hunched down), level smooth road, and motor/controller/rolling friction efficiency of 90%, it would take about 125 amps at 84 volts to push the scooter and rider at 70 mph., so that does push the current a bit above 3C.

I agree that a faster, larger scooter really needs to be using the 60AH cells.

My own Thundersky packs have done fine with a 2.5C draw for extended spells such as climbing long hills. But at below freezing temperatures and 3 years of age, the voltage sag is getting intolerable.

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Re: Test Ride of the ZEV Scooters

Thanks Paul. Good review - it seems to confirm what I suspected. It sounds to me as if I'd call these an "X-Treme-Plus" kind of experience. They certainly offer some upgraded capability from the "standard" for this chassis (X-Treme, EFun etc.) - but nothing that leaps out and puts them in a class alongside an established brand like Vectrix, Brammo or Zero. I admit that I'm skeptical about the frame being much different than any of the others in this class - maybe a longer swing arm? Adding to this skepticism are a couple of red flags like insisting that the throttle mapping is because of too much power and the transmission being a set of different amp settings. Like you, I'd agree that different amp settings are worthwhile - in fact we have something similar to that - but to call it a transmission is simply wrong. A transmission modifies the torque behavior not the available power.

I'd love to get you to review one of our scooters one day. Maybe we can figure something out...

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

Hi Paul,

jdh2550_1 wrote:

Thanks Paul. Good review.

...Adding to this skepticism are a couple of red flags like insisting that the throttle mapping is because of too much power and the transmission being a set of different amp settings.

Thanks! Excellent review!

Only two red flags? Sounds to me like the skeptics were correct and my optimism was wishful thinking.

Thanks Again!

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Best Wishes!

Mitch

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Re: Test Ride of the ZEV Scooters

MitchJi wrote:

Hi Paul,

jdh2550_1 wrote:

Thanks Paul. Good review.

...Adding to this skepticism are a couple of red flags like insisting that the throttle mapping is because of too much power and the transmission being a set of different amp settings.

Only two red flags? Sounds to me like the skeptics were correct and my optimism was wishful thinking.

I was only referring to the skepticism about the amount of alterations done to the frame (vs. the other bikes that look like this one) and why I would remain skeptical about this given some of his other answers. You kind of quoted me out of context.

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

Over the past 10 days, I've commuted 5 times on my new ZEV 7100. (delivered 2/5/11)

My commute route is 27 miles each way along the coast in Central California (Santa Cruz<->Moss Landing). I charge the bike fully at each end.
10 miles freeway (65mph), 12 miles two lane(45mph) farm roads, final 5 miles two lane(55mph) highway.
I've ridden about 20kMiles on a Honda Helix (250cc) and, more recently, 70kMiles on a Suzuki SV/650.

Here are how my impressions compare with PJD's:

1) The brakes have, thankfully, been much improved. Mine are smooth, easy to modulate and silent.
There is very little fork dive, probably due to the low CG.

2) The bike will sustain 125kph (indicated) on level freeway without me having to "tuck in"
(I just can't bring myself to look that silly while perched on a scooter :-)
Indicated top speed slows to 115kph up rolling hills, but it never goes below 105kph on the freeway portion of this route.
I'm 5' 9" 145lbs, plus about 20lbs of gear.

3) The speedo appears to read about 10% high. I need to confirm this against GPS soon.

4) I arrive at each end of this route with 20%-25% charge remaining.
Bulk charging finishes in about 2.5-3.0 hours plus 30 minutes or so to top off (balance) the pack.

5) Nothing gets hot. Even when running flat out for minutes at a time, the controller and motor are just comfortably warm.
It's also eerily silent. No chain, no gears. All this indicates, to me at least, that not much energy is being wasted.

6) The two lane farm roads I ride between the (relatively smooth) Hwy 1 sections are full of patches and pot holes.
The frame never feels like its overwhelmed, but I get the occasional jarring bump from the rear.
(I've yet to make any adjustments from the stock settings on the rears. The front forks are not adjustable)
The suspension is quite a bit better than my old Helix's was (not saying much)
It's still not nearly a sorted as my SV/650 (no surprise there) or the Vectrix.
(Yes, I test rode the Vectrix. Very smooth, excellent throttle control, very heavy)

7) The gauges are pretty much useless. I've already ordered a Cycle Analyst.

8) The throttle is twitchy. For fun, I tried the DMV test while waiting there. Couldn't do it. Maybe I'll be steadier after more beer.
In practice, the throttle is is especially annoying while trying to maintain speeds between 60 and 80 kph on bumpy tarmac.
The latest Cycle Analyst firmware has a current control servo feature. This makes the throttle control torque rather than motor pulse width.
I'm hoping to tame the ZEV's throttle by this means.
(Stay tuned...)

9) The brake lights are insanely bright. The headlights are adequate.

10) The ZEV 7100 does exhibit a bit of hesitation on turn in. Yes, it probably is the result of its low CG and long wheelbase. However, it's these qualities that also give this fairly light scooter a feeling of stability at speed.

It is still a bit early to tell how the battery will hold up. But there's no sign yet of any change in performance.

So far, it's doing everything I'd hoped it would. Time will tell...

Do you folks know of any other electric motorbike one can buy today for less than $15,000 that could run this route at posted speed limits?

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Re: Test Ride of the ZEV Scooters

Sounds like you've got a good bike, and a good commute to match the bike. I hope it continues to work out well for you.

genosensor wrote:

Do you folks know of any other electric motorbike one can buy today for less than $15,000 that could run this route at posted speed limits?

Well, actually, you should follow the links in John Harding's signature. The Current Motor Company C130 has both the range and the speed for your route, and is currently listed at $8k, and test pilots can get the bike at $6k.

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Re: Test Ride of the ZEV Scooters

Genosensor,

I look forward to your next update with the cycle analyst hooked up. I would like to know what % of regen you are getting.

Thanks

__________________

Motorcycle: ZEV 6100, 77V, 40AH, 60+mph; Cycle Analyst, LED head lights, 3 Cell Log interfaces, TNC throttle and faster charger added. 6,800 miles so far.
Cost to date: $730, MSRP $6550 - $4120 tax credit - $1200 referrals + $500 mods -$1000 in gas savings.
Big EV Grin. :)

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Re: Test Ride of the ZEV Scooters

I recently read the posting of PJD regarding his experience driving three ZEV scooters. Up until now I have not posted anything on the V is For Voltage website, but after reading this review which I feel missed the mark on a couple of levels, I felt compelled to weigh in.

I purchased my first electric scooter; a one year old X-Treme XM 2000 (1500 watts) about two years ago. Shortly after this purchase I purchased a new Zapino for my wife. The quality of the Zapino was better than the X-Treme XM 2000, but neither were hill climbers, so I searched around for a scooter that was actually usable where I live in northern California. I found a scooter that was manufactured by Mountain Chen in China and imported by Angren Sky Commuter. It claimed to produce 4000 watts of power and had lithium batteries (LiFePO4). Before I purchased this scooter, I raced it against an X-Treme XM 5000 and found that the acceleration was about the same. The XM 5000 had a higher top speed and a much higher price tag, so I bought the Angren Sky Commuter model, which was named “Thunder”. I tested Thunder’s hill climbing ability in San Francisco on some really steep hills and it performed well. I brought Thunder home, which is approximately five hours north of San Francisco and drove it do errands and a little bit of commuting.

All was well until I let someone drive Thunder who didn’t have much experience with driving electric scooters. Thunder proved to be too powerful for him. He panicked holding the throttle wide open. He couldn’t get himself to trip the micro switch on either brake as I told him to do if he got in trouble. His speed was too fast to negotiate a turn and consequently ran over a meridian, then continued across a sidewalk and finally began climbing up a steep dirt embankment where Thunder fortunately lost traction and came to a stop, with the throttle still cracked wide open. Much to my relief no was hurt, killed or run over (big lesson here). The driver suffered only a bruised ego and returned Thunder back to me stating it was too powerful for him. I mounted Thunder and discovered the rear tire was flat. Upon further inspection I noticed the rear wheel had been distorted, breaking the seal on the tubeless tire so it would no longer hold air.

At first I thought this was going to be an easy and inexpensive repair. I thought I could purchase a new rear wheel and exchange the motor assembly from the damaged wheel into the new wheel. Unfortunately, it was not that simple. I called the X-Treme company, but I was told that the scooters they sell are not equipped with the larger diameter motor which came on Thunder (this is why Thunder which is rated one thousand (1000) watts less than the XM-5000 had the same acceleration; more about this later). Even if I wanted to switch to the smaller diameter motor, I was told that they did not have the 5000 watt motor in stock and that they do not do special orders. I called and spoke with Mr. Angren in Norway, but he told me that they only sell complete scooters, not parts. I contacted other companies in the U.S. but did not have any success finding what I was looking for. I then started contacting companies in China. I found websites and emailed them requesting to purchase parts. I did get some response, mostly from sales people who wanted to sell a container of new scooters, but not parts. As soon as they found out I was an “end user”, they stopped responding to my emails. It should be noted that bringing scooters into this country might be easy, but being able to register them with DMV is a whole other story.

After a couple of weeks of nothing but frustration, it appeared that I was going to have to purchase a complete rear wheel assembly which included a motor and a compatible controller. I continued to explore finding a company in China to sell me the parts I needed when one day an engineer who works for a manufacturing factory in China suggested that I speak with Darus Zehrbach of the ZEV Company in the U.S. I called Darus and after hanging up the telephone I let out a huge sigh of relief and said to myself, “Finally”! Darus is not only knowledgeable about electrical components and electric scooters in general, he was willing to sell me the parts I needed and guide me through the process of exchanging components to get Thunder back on the road.

Thunder came equipped with a 60 volt/80 amp controller, but it had 24 lithium battery packs, meaning it had a 72 volt battery system (84 peak volts) and was evidently mismatched from the factory back in China. Darus suggested I switch to a 72 volt controller and run the motor he installs on his ZEV 6100 model. Darus explained that his larger diameter motor will perform better than the smaller diameter motors, which is why Thunder’s acceleration was equal to the XM-5000. Here is what he told me: “The outside diameter on the ZEV motor is 12 inches, whereas the outside diameter on the X-Treme XM 5000 model is about 9 inches, even though they both use a 13 inch rim. If you have 200 Nm of torque in a 12 inch motor mounted in a 13 inch rim, the real and effective torque is 12/13 = 92.3% X 200 Nm or 184 Nm at the rim. On the XM-5000 motor the torque is 9/13 or 69.2% X 200 Nm which is approximately 138.46 Nm, or about 75% of the torque of the ZEV motor. The combination of the larger diameter motor and the superior ability to transfer heat away from the motor, not only gives the ZEV motor more initial torque, but it only improves as the smaller diameter motor gets hot”.

Having successfully completed the conversion, I now have a scooter similar to the ZEV 6100 model. I say similar because my scooter does not have regenerative braking, battery management, gas shocks, the ZEV non Chinese frame, etc. It is similar in that it has the same controller, motor and batteries. So, the road test of my scooter should be almost identical to the ZEV 6100, with the exception that my scooter does not have a windshield and air resistance will factor in on the test. There is a safety corridor between the city where I live and the next city south of us. The speed used to be 65 mph, but it is now 50 mph and there are two speed indicators in one direction and one speed indicator in the opposite direction. The road is relatively flat and during the test the air temperature was about 50 degrees and there was a wind of about 10 to 15 mph. Fully dressed I weigh about 140 pounds. The results of my test produced an average two way speed of 61 mph with the battery pack at approximately 81 volts. A new ZEV scooter would have a battery pack which produces 84 to 86 volts, but my scooter’s batteries are now over a year and a half old and therefore the ZEV 6100 scooter should be capable of higher speeds than my scooter. (Remember, more voltage equals more speed). The ZEV 7100 runs an 84 volt battery system (96 peak volts), which should be capable of substantially higher speeds than what my scooter is capable of. I am confused why PJD could not attain the advertised speed of the ZEV 7100 going “downwind/downslope”.

In conclusion, I am sharing this information with you mostly because of the comment PJD wrote; “The ZEV scooters are, externally, a common Chinese-style scooter with electric versions like the E-Fun, X-Treme, R Martin and others”. The reality is that anyone can order a container of Chinese scooters and put whatever name or brand they choose on them. When that model becomes obsolete, so does the parts supply for that scooter (this information is from the parts guy at X-Treme). When you purchase a scooter from ZEV, not only are you guaranteed to be able to register it with DMV because it comes with a U.S. vehicle identification number (VIN), you will have the assurance that replacement parts will be available if needed. Keep in mind that ZEV is considered a manufacturer, being that the final assembly of the scooters is done in this country, not a retailer of Chinese scooters as all of the other companies PJD mentioned are. Darus has stated that he travels to China several times a year to meet with parts suppliers and he continues to find ways to improve the components that are installed on the scooters which he sells. He strives to assemble dependable machines that owners can rely on and use as their primary source of transportation, if they choose. Darus is generous with his knowledge and expertise of electrical components and he will gladly help you sort out your problems. Regardless what his position is on global warming, or what side of his head he parts his hair on, Darus is doing a tremendous service for the electric scooter industry in this country. Let’s support him.

Jim Gurman
Arcata, Ca

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Re: Test Ride of the ZEV Scooters

I finally got the Cycle Analyst installed on my ZEV7100 scooter. See attached:

Cycle Analyst on ZEV7100
Cycle Analyst ZEV7100 wiring

It was a bit of a challenge to install cleanly. Darus at Z Electric suggested the location. It looks like it belongs there:-)

The Analyst does coulomb counting to provide an accurate indication of remaining range.
It indicates speed much more accurately than the pretty analog speedo does.
And, I've wired it to convert the standard PWM style throttle into a "torque throttle".
Essentially, this makes the amps output to the motor (torque) directly proportional to the degree of throttle opening.
This makes the throttle behave much more smoothly. I test rode a Vectrix a while back and was very impressed with their throttle behavior. My ZEV now behaves much the same, minus the reverse gear and regen features.
The little black switch next to the Analyst selects whether the throttle should be passed through it or go directly into the controller. Its mainly for testing -- and getting home again should the Analyst fail for some reason.

Speaking of regen:
Darus says that the ZEV controllers used to do a significant amount of regen whenever the brake light illuminated. Trouble was, there was no modulation on this. It engaged suddenly at the slightest squeeze on a lever. He says folks didn't like it, so it was toned way down. In practice, I'm not seeing any measurable regen, although Darus claims there is a small amount. In any case, there's really not much point to regen on a vehicle of this weight. The ability to freewheel (coast) efficiently is more important for range. And, if you are going to have significant regen, you really want to be able to modulate it, like the Vectrix did with their patented reversible throttle. Otherwise, one might slide the rear tire on a slippery road.

Today, I used about 20Ah to go 22 miles. The road was wet and the route was not flat. Avg speed was about 30mph. Top speed about 50mph.

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- brent

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Re: Test Ride of the ZEV Scooters

Thanks for the update. It looks great.

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Motorcycle: ZEV 6100, 77V, 40AH, 60+mph; Cycle Analyst, LED head lights, 3 Cell Log interfaces, TNC throttle and faster charger added. 6,800 miles so far.
Cost to date: $730, MSRP $6550 - $4120 tax credit - $1200 referrals + $500 mods -$1000 in gas savings.
Big EV Grin. :)

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Re: Test Ride of the ZEV Scooters

Nice installation - good job!

What size are the batteries on your ZEV? Are they 40Ah or 60Ah?

As far as regen goes - check out MikeB's post on the C130 to see how we do it (oh, and we've a patent application in for our approach - don't know if it will be granted but seeing as VX got all "patent happy" we figured we'd better try and protect ourselves.) I do agree that freewheeling is more effective than regen - and I used to think that same thing regarding regen vs. weight. Until a buddy pointed out the fallacy of that argument - yes, you can regain less energy, but it takes less energy to accelerate the lighter vehicle. It's a complex model to figure out all the pro's and con's of regen and it might still be that for a light vehicle it's not terribly worthwhile - but it's not just because of weight. My approach to the problem has been "customers want regen - how can I give them a good and cost-effective system?"

Does your cycle analyst have a bi-directional current sensor? If so, you should see Ah go negative when regen is occurring. Alternatively put the bike on the center stand, turn the lights on main beam and note the current draw. Now open the throttle and get the rear wheel spinning fast. Let off the throttle and you should see the Amps go back down to the same number as when the headlight was on. Now repeat that test but pull in the front brake and see if the rear wheel slows or the Amp draw goes down below the A drawn by the headlights. I think that this experiment should tell you if you're really getting any regen.

If you're not then it doesn't sound like it's really a big deal for you - but if a customer is expecting regen then it should probably be there...

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

John,

All LiFePo4 powered Z-Electric's ZEVxxxx models have 40Ah batteries
The Trail models, based on a larger frame, have 60Ah batteries
see http://www.zelectricvehicle.com/15.html
and http://www.zelectricvehicle.com/18.html

I choose the ZEV7100 because I like the svelte body style and the relatively light weight for a freeway capable scooter.
It's really fun to ride. Very "flickable", as the batteries are mounted low in the frame.
Your C130 looks to be comparable in performance, but it is >100lbs heavier.
Your bikes were not yet shipping at the time I placed my ZEV order. If your "test pilot" program had been available, I would have been seriously tempted.

When I compare the bikes now, what I honestly don't understand is why, with >50% more energy on board, the C130's quoted "real-world" range appears to be so similar to that returned by my little ZEV7100? The extra weight should not make much difference on flat pavement, right? I'm seeing 40+ miles at 35-45mph on real, somewhat bumpy roads with gentle grades and occasional stops.

Regarding Regen:
Yes, the Cycle Analyst measures current in and out of the battery. My ZEV7100 appears to do absolutely no regen under any circumstances -- except when charging :-) I only determined this a few days ago.
It is still possible that there is something wrong with my particular bike's controller. If not, I certainly do agree that Z-Electric should not advertise a feature they don't currently implement.

I have read MikeB's post on how the C130 now implements regen. I guess two or three regen levels are better than one (or none). It is too bad the Vectrix folks patented their reversible throttle. I rode that bike for 10 minutes or so while they were demoing in San Francisco. They got regen and throttle handling right, but the bike felt massive. Still, if only they'd put lithium cells in that thing, they might well still be in the black. Did you ask them about licensing their design?

As your friend pointed out, regen on a light vehicle can be effective. To be more precise, regen can be effective when a significant proportion of the total energy expended to move the vehicle is stored in it as inertia. This is not the case for most scooters and motorcycles traveling >30mph or so. Bikes are not very streamlined. Most of the energy at speed is being dissipated as drag. One cannot get that energy back. The fact that you must use full power just to *maintain* highway speed and half or so at 40mph means that energy is being dissipated, not stored. Regen would work best on a train, a large truck, or a even a light, very streamlined, car -- like the Aptera.

I suppose, however, that riding around city streets or up and down extreme hills at low speeds might provide an opportunity for regen on a scooter to extend range >10% or so. I just don't have any of those situations within 25 miles of my home. I've got some fun mountains nearby, but I don't take the descents slowly enough to "ride the brakes", so I won't benefit much from regen there. Drag keeps the speed in check, aside from the braking for the occasional tight turn.

Here's a good thread about regen's effectiveness:
http://www.diyelectriccar.com/forums/showthread.php?t=8848

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Re: Test Ride of the ZEV Scooters

Hi Brent,

We use a conservative "real world" range estimate probably based on more high speed riding than you. Yes, we have more than 50% more capacity and I would expect a similar (but slightly less) increase in range. What is the maximum that your controller lets you take out of the pack - it should be no more than about 32 Ah (80% of 40Ah). Also, have you tested the accuracy of your odometer? (if you're using the CA for range that will be accurate assuming you've programmed the right wheel size - which I'm sure you have!). Also, have you actually weighed your bike? We weighed an EMoto G6 the other day and were "distressed" to find out that it was significantly heavier than they claimed.

You obviously understand the whole regen debate. Riding around city streets or with extreme hills is not that unusual a usage scenario. However, that's why I decided to sidestep the whole debate and just go with "our customers want it, we'll figure out how to give it to them". We didn't look at licensing - didn't really want to go there and be beholden on a competitor and, if the prices of their bikes are anything to go by I expect it would have been an expensive deal to make!

I don't mean to "beat up" on you. I truly am glad that you've got a bike that you like. Welcome to the club!

OTOH, I dislike it when I hear "stories" like "well, we have a very small amount of regen because anything more would be bad" only to find out that it has no regen. (However, like you, I wouldn't particularly worry about the lack of regen).

Happy riding!

John H.

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

Brent,

"All LiFePo4 powered Z-Electric's ZEVxxxx models have 40Ah batteries"

Actually, the ZEV5100 Long Range uses 60 Ah cells.

Warren

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warren

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Re: Test Ride of the ZEV Scooters

Motorcycle manufacturers are notorious for understating weight, so, per your hint, I weighed my ZEV7100 scoot today.
It took all of 60 seconds with our calibrated postal scale. Sum the weights on each wheel while carefully balancing bike:

345 lbs (including the separate 7 pound charger)

The weight stamped on the government label is 305 lbs.
Gas bike manufacturers often weigh their bikes "dry". Without fuel, oil or coolant.
Do E-bike manufacturers weigh their bikes without electrons? ;-)

Google Earth offers a fun way to visualize a route taken. Just set a a smart phone to track your location while you ride home with it in a pocket. I use an Android app called "Torque". The attached kml file should superimpose my usual (scenic) route home onto Google Earth with speeds updated every 5 seconds.

Change file extension from gif to kml

I calibrated the Cycle Analyst against the GPS for speed and a non-contact (hall effect) ammeter for current.
Here are stats for the above trip home:


Miles 25.89
Elapsed Time 39m 18s
Amp-hrs 28.84
Watt-hrs 2468
Wh/mi 94
Avg Speed 39.5 mph
Max Speed 67.9 mph
Max Amps 116.9
Min Volts 81.5
Initial Volts 95.8
End Volts 90.1

Since I had the Cycle Analyst installed, I've never run the pack down to its cut off, so I really don't know where it is set. I have taken as much as 33 amps-hrs out. I guess I'll have to try high speed runs until I see it start to cut out, then limp home at low speed. Or, just leave the headlights on after I bring it home nearly depleted...

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Re: Test Ride of the ZEV Scooters

Talking about 3 gears... I was researching how this worked when I happened across the sales person at the actual manufacturer in China who makes almost all the components for Liberty in PA -- According to Liberty, the parts are mostly made are in China and are bought to the US for assembly... The group of factories in China, represented by a few "agents" sell a fully constructed bike with a 5500 watt motor with a top speed of 80MPH DOT & EEC certified, which includes a "3-gear-boost function" -- for about $3k (using LFP batteries!), which includes shipping to the West Coast (USA). Hmm... who else uses this same manufacture. I've seen virtually identical scooters from a number of different "manufactures" in the USA now.

My biz partner in China talked to "him" (PM me if you want the name and contact number) said, that the 3 speed [computer controlled] "boost" function can be disabled at the time you place an order, however it leaves the scooter in "economy mode" -- I assume that means "first gear" and cannot be changed. I'm trying to get a answer as to see if the "gear" can be set to some kind of power mode (forget the button) and scale power/gain with throttle, like I suspect my Vectrix VX-1 does. "He" claims that the this boost function is very popular feature, and he couldn't quite understand why I kept asking him to explain to me in detail how it works and why would I want it... ;-)

On a related note -- At that price I will probably place an order for at least a couple of scooters to play with and share among friends and family, then sell for a profit... I was told that if you order 20 scooters you can even have your own brand-label placed on the scooter at no extra charge -- what fun! I cold have a scotter-scooter logo! I love my Vectrix VX-1 more than life itself, but can't afford to buy 3 more of them, unless I buy used ones (the guys at Vectrix have been great to work with). I may praise Vectrix even more if it turns out the Chinese scooters are junk.

Anyway, I digress (sorry). But if I learn that the 3-gear-function can be adjusted, I'll let you know.
--Scotter

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--Scotter and his scooter
2007 Vectrix VX-1 Maroon
2007 Vectrix VX-1 Silver
2008 Vectrix VX-1 Blue
2008 Vectrix VX-1 Silver
Other EV projects in the works

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Re: Test Ride of the ZEV Scooters

The three gears are useful with the ZEV7100's standard, twitchy PWM throttle. Using as low a gear as possible saves watts and provides a less jerky ride. After I installed the Cycle Analyst, which converted the raw Pulse Width Modulation throttle into a torque control, the gears become more of a nuisance than a help, as, even at "maximum boost" I can make the scooter crawl smoothly at speeds a good deal slower than one would walk. I've thought about adding a little circuit to automatically close the gear change button switch until gear three was selected. Or, it may be possible to defeat the circuit that switches back to low gear whenever the bike completely stops. In practice, one quickly learns to stab the gear change button when accelerating from a stop. However, in town, I often leave it in low gear, as it limits speed to about 27mph. Otherwise, the scooter is so smooth and noiseless that one quickly finds oneself doing 35 in and 25 zone.

Z-Electric sources parts from a number of Asian nations. Fact is, that's where most of volume in the scooter market is. The ZEVxxxx scooters borrow their bodywork and much of the running gear from the E-fun electric scooter. Z-Electric has replacement frames custom built in China. That frame is very stiff -- much better than the frame of my Japanese Honda Helix was. And, it integrates a very solid, deep steel tub for the batteries. They also upgrades various parts to improve handling, like the swing arm and adjustable air shocks in the rear. By the way, Z-Electric's "trail" models borrow bodywork from this cool Thai electric scooter:

http://www.gizmag.com/the-toyotron-hunter-electric-motorcycle/9731/

which itself seems to be a clone of Honda's big 250cc Ruckus

Current Motor Co. very likely sources their scooter body and running gear from Nanjing Research & Development, based in Jiangsu Province, China:

http://www.roketa.com/product/1/0/2621.shtml
http://gokartsusa.com/roketamc-13bali150mopedscooterfreeshipping.aspx

This 150cc gas scooter retails for $1,388.00 *with free shipping*.

I remember reading that Current Motor also has replacement frames custom built for them in China.
From the spec's on bike's on board charger, it's very likely to be one of these:

http://www.electricforum.com/cars/buy-sell/2061-pfc-charger-waterproof-onboard-dual-input-voltages.html

They are about the only sealed, 1.5Kw charger available that handles 96V LiFePO4 packs. Again, Chinese.
Retail for about $350, less in volume. By all accounts an excellent charger, if a bit heavy.
I've been looking for an integrated on-board charger for my ZEV7100, but I think I'll opt for the lighter (more expensive) Delta-Q QuiQ, designed in Canada, built in, you guessed it.
The batteries in all these LFP scooters are, of course, also of Chinese manufacture.

So, as I see it, the product development processes at Current Electric and Z-Electric are very similar. It really has to be, as neither company is large (or well capitalized) enough to produce, or even design, many custom components on their own. I call it "Engineering by shopping" It's fun and very appropriate for low volume work.

It makes no difference to the end customer, especially these days, from where vehicle parts are sourced. What matters is how well the final integrator chooses those parts, assembles them, and, most importantly, how well they support their customers.

The real problem with buying direct from wholesalers selling product without a significant profit margin is that they cannot support customers with small orders. US and Japanese wholesalers solve the problem by forcing end users to buy through exclusive dealer networks that mark up the price. It seems the Chinese and other Asian manufacturers will sell in much smaller volumes to just about anybody and let the buyer beware.

An 80MPH scooter powered by a 5.5kW motor is just about impossible to believe, but they might do 65mph. I'd try to ride one before buying it. If they check out, then, by all means, buy those Scotter Scooters. In any case, please do PM me with your Chinese connection's contact info!

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Re: Test Ride of the ZEV Scooters

genosensor wrote:

So, as I see it, the product development processes at Current Electric and Z-Electric are very similar. It really has to be, as neither company is large (or well capitalized) enough to produce, or even design, many custom components on their own. I call it "Engineering by shopping" It's fun and very appropriate for low volume work.

You're exactly right on this. There's an art to taking off-the-shelf parts and assembling a final product with them, done right it can make for a good product with a very reasonable cost. You gain the advantage of in-house quality control for the assembly, which tends to be much better when done in the US than in China. There's no good reason to design brand new plastics and a rolling chassis when you're expecting a small production run, but it's nice to make sure all the screws are properly tightened as you put things together.

But there's also an interesting element of engineering for the parts that aren't off the shelf. On the Current Motor Company bike, they build the BMS and BCU themselves. The BMS is a derivation off the Goodrum-Fechter design, and the BCU is pure custom work (and John is the programmer). I assume that Z-Electric also has a few key pieces of the bike that they build in-house, which make their product better than the standard Chinese import.

And those little in-house engineering pieces often make (or break) the product. The BCU in the Current bike does much of the tasks of your added Cycle Analyst, like tracking power in/out to the battery, among other things. The BCU also adds better temperature monitoring, so they can run more power through the hub motor than it's rated for (since the rating is based on a constant load, rather than burst). The ZEV 'gearing' appears to be a nice little bit of value-added work as well, though it appears there are other ways to solve those issues.

I think we're going to be seeing a number of small companies taking this approach in the next few years. I also suspect that while they compete for customers, they may also find it advantageous to share these little pieces of custom engineering among themselves, or at least the ideas behind making them work.

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Re: Test Ride of the ZEV Scooters

Brent,

Thanks for all the details.

My take on the ZEV's - Darus's focus is to build high quality, fast, light-weight scooters at a reasonable price. The emphasis is on reliablity and performance and less on Cycle Analyst-type instrumentation as he tries to keep up with orders coming in. The bikes seem to have been designed more for the sport or racing enthusiast instead of the student trying to get down to the local cafe. I was very impressed with the wide temperature design and testing that went into his controller and motor. I've worked for two manufacturers of extreme temperature range computers, and it was clear that Darus was doing all the right things to produce a high reliability drive train. Early reports on the C130 overheating issues made me very nervous. Hence, why I bought a ZEV.

I'm not sure I'll add a Cycle Analyst to my ZEV; only reason would be for the smoother throttle. For voltage, amp, amp hr, I believe I can tweak gauges within the instrumentation panel.

Isn't there another approach to smoothing the "twitchy" throttle besides routing it through a CA?

Thanks,

__________________

Motorcycle: ZEV 6100, 77V, 40AH, 60+mph; Cycle Analyst, LED head lights, 3 Cell Log interfaces, TNC throttle and faster charger added. 6,800 miles so far.
Cost to date: $730, MSRP $6550 - $4120 tax credit - $1200 referrals + $500 mods -$1000 in gas savings.
Big EV Grin. :)

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Re: Test Ride of the ZEV Scooters

genosensor wrote:

Current Motor Co. very likely sources their scooter body and running gear from Nanjing Research & Development, based in Jiangsu Province, China:

http://www.roketa.com/product/1/0/2621.shtml
http://gokartsusa.com/roketamc-13bali150mopedscooterfreeshipping.aspx

I remember reading that Current Motor also has replacement frames custom built for them in China.

Not quite - we source our frame and bodywork from a different Chinese supplier - the actual source factory of the original bike in this style. We do significant upgrades to the frame, have our own swing arm and our own battery box - all manufactured and installed locally in the USA. We also upgrade the suspension (parts are sourced in Taiwan and assembled locally.

Quote:

From the spec's on bike's on board charger, it's very likely to be one of these:

http://www.electricforum.com/cars/buy-sell/2061-pfc-charger-waterproof-onboard-dual-input-voltages.html

No, we source a different charger from a different supplier and we have them built to our specification to interface to our BMS and BCU. It's a custom part.

Quote:

The batteries in all these LFP scooters are, of course, also of Chinese manufacture.

Correct. Although it does appear that the price of A123 cells may come down to "almost affordable to us" rather than "far too expensive". Apparently their target is $400/kWh for volume purchase - raw cell only. We pay $360/kWh - ready for assembly into a pack.

Quote:

So, as I see it, the product development processes at Current Electric and Z-Electric are very similar. It really has to be, as neither company is large (or well capitalized) enough to produce, or even design, many custom components on their own. I call it "Engineering by shopping" It's fun and very appropriate for low volume work.

No!

OK, this is where I may come off as more than a little biased. But I have about 3 years and several hundred thousand personal dollars invested so far (and I'm not the only investor). We are not approaching this as a "boutique" or "lifestyle" endeavor. Yes, we're starting small - but we're seeking significant funding and our goal is to be the best-in-class in the top 20 markets. There will be more Current Motor Company bikes on the road than Vectrix. Just as there are more Fords than there are Cadillacs. We already employ a staff of 12. This year we have a modest goal of around 200 bikes. We will lose money. Next year we will sell more and we may break even. In year 3 we will be profitable and expanding quickly.

As I understand it Darus' operation is far smaller and more modest. Perhaps him and just one or two others in the US (and let's face it when we're talking about made in the USA we're ultimately most interested in job creation). That's fine, no disrespect intended - it may be a viable approach but will likely always be size constrained. In general investors don't want to invest in a "lifestyle" business. However, I do not believe that we are in the same category as Darus. We are in the same category as Vectrix, Zero and Brammo. Our bikes cost far less but they already out perform those bikes in most respects. Again, we're the Ford and not the Cadillac (or BMW, or whatever luxury brand you want). Or perhaps another way of looking at us is to consider the progression of a company like Hyundai - they started in the US market in a very humble position. They are now ranked 3rd or 4th most reliable behind Toyota, Honda & Mistibushi (I usually discount Mitsibushi because there sales numbers are tiny compared to the others).

I guess the jury is still out on this one - but keep checking on Current Motor Company's progress (and our transparent advertising - for example you could ask Mike B how heavy his bike is and how the regen works ;-) ). Above all - keep me honest!

Quote:

It makes no difference to the end customer, especially these days, from where vehicle parts are sourced. What matters is how well the final integrator chooses those parts, assembles them, and, most importantly, how well they support their customers.

I almost agree. It does make some difference - both in quality and in our domestic economy (and that affects everyone). We actually have a plan in place to increase our domestic "made in USA" content significantly over the next few product cycles.

Quote:

The real problem with buying direct from wholesalers selling product without a significant profit margin is that they cannot support customers with small orders. US and Japanese wholesalers solve the problem by forcing end users to buy through exclusive dealer networks that mark up the price. It seems the Chinese and other Asian manufacturers will sell in much smaller volumes to just about anybody and let the buyer beware.

An 80MPH scooter powered by a 5.5kW motor is just about impossible to believe, but they might do 65mph. I'd try to ride one before buying it. If they check out, then, by all means, buy those Scotter Scooters. In any case, please do PM me with your Chinese connection's contact info!

I agree with this 100% (see, I'm not all bad!) Buyer beware. Also be sure that you'll get all the paperwork to allow you to register and use the bike. Mike Kelly bought a low cost sample bike from an importer and was left with a bike he couldn't register. He's now a Current Motor Company customer.

BTW, if I seem a little coy on some of the specifics please bear in mind that I'm actually sharing WAY MORE than any other manufacturer does. I think I first posted on this forum in 2007. I'm committed to the two wheel EV scene. I started a company and put my money where my mouth is (I know I have a big mouth and I know I often put my foot in it). I'm happy to share info and ideas up to a point (there are a couple of items in this post that our Board Chair might well have wished I said differently). But, if you decide to do some well-intentioned "reverse engineering" don't be surprised if I step in and try to correct it.

Do not assume that Current Motor Company is "just an assembler who changes a couple of bits". Not so. Not by a long shot.

(p.s. I'm not at all offended or angered by your post - but it is very important to me that people understand that Current Motor Company is passionate about doing this right and committed to doing this right for a long time to come)

Happy Friday everyone.

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

IBScootn wrote:

Early reports on the C130 overheating issues made me very nervous. Hence, why I bought a ZEV.

Yup, fair comment. We believe we've addressed these particular issues - but we still have a little way to go. That's why we offer our test pilot program with $2000 off. Mike B, the brave soul that he is - customer #001 no less!, helped us realize that we would be asking too much of our customers without compensating them for some of the unexpected hiccups for a new high-tech product. And, because we realized that *after* we accepted payment from Mike we actually gave him (and the other few bikes in this category) a refund check.

We did this of our own choice. Not because anyone complained or demanded it.

Again, I'm not knocking Darus and ZEV. I'm just saying we don't compare ourselves to them, instead to the "big boys" - Brammo, Zero and Vectrix. All the above pontification is the reason we see the world the way we do.

Happy riding whatever you ride!

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Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

I, too, was and continue to be impressed with the ZEV's conservative thermal design. The motor is rated for 7Kw continuous and that's about the maximum the controller will output. Hot motors and electronics mean increased resistance, which leads to more heat generated and thermal runaway. The idea of overdriving the motor briefly for bursts of acceleration is interesting, but what happens when one tries to climb a long steep grade at speed or hold top speed on the freeway? Once the motor gets hot, you've got to back power down quite a bit (below its continuous rating) to cool quickly or it will continue to run hot and inefficiently for quite a while. All the "big boys", and especially the Brammo Inertia, appear to have had serious thermal issues.

I don't know about racing or sport. None of the currently available electric bikes compare to an inexpensive, run-of-the-mill 600-650cc sport bike. I think we'll have to wait for the Brammo Empulse before sport or racing enthusiasts plug in to the electric revolution.

There's no reason to rush to add the Cycle Analyst. If you have a steady throttle hand, you'll do fine with the direct PWM throttle. Going without a state of charge indicator is difficult, however. Darus is working on improving the existing analog voltage gauge and has said he will supply a kit to install after he's got it working to his satisfaction. It won't be a coulomb counter, but it should give enough information to know when you are down to 50% or 30% charge remaining. The current gauge doesn't unpeg until you are >90% depleted.

One thing I like about the Cycle Analyst over an integrated BCU is that it is primarily a passive monitoring device. Its total failure would just take out the throttle prepossessing, at which point, I'd throw my nice little mechanical switch to bypass it and continue on my way.

I really don't know of any practical analog approach to fixing the "twitchy" throttle. The torque throttle the Cycle Analyst provides could and should be integrated into the bike's motor contoller firmware at some point. Yes, there's a little microprocessor in that too, and it even has a programming connector for downloading firmware updates.

The Cycle Analyst is a good deal at <$200, but it is pretty geeky. If you do decide to get one, I'll post more info on configuring and installing it on the ZEVxxxx bikes.

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Re: Test Ride of the ZEV Scooters

I'm sorry, John, but you, as you say, are a little biased.

Today, the ZEVxxxx and Current Motor scooters are very similarly spec'd vehicles.
Similar body styles, similar performance, similar price. Any informed prospective customer would see that you are direct competitors, at least for the time being.

I just noticed that even the hub motor casings are the same. Darus has started painting his all black, but if you look closely you can see the same logo on each. They both say "Super Power Motor" in the same font. The ZEV appears to have more allen screws holding it together. It's hard for me to imagine that these hub motors don't roll out of the same Chinese factory.

Feel free to compare:
http://www.concentratemedia.com/features/currentmotors0112.aspx
http://www.zelectricvehicle.com/4.html

How you intended to maintain that you could post an unbiased evaluation of a direct competitor's product is beyond me.
It would have been far better to have let someone uninvolved with either company do it.

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Re: Test Ride of the ZEV Scooters

genosensor wrote:

How you intended to maintain that you could post an unbiased evaluation of a direct competitor's product is beyond me.
It would have been far better to have let someone uninvolved with either company do it.

You're right. Time will tell, but alas, I'm not very patient.

BTW, you also made some wrong guesses in your comparison, as well as some right ones. If nothing else it was appropriate to correct those.

I hope an independent tester does a side-by-side comparison of bikes sometime soon. I'll happily loan one of our bikes to an independent testing company with an appropriate reputation as unbiased. They will need to commit to providing an objective test of ZEV, Current, Brammo, Zero and Vectrix. I'd hope that this would serve my competitors as well as it will serve my company.

It needs to be an on road, side-by-side test. Comparing spec sheets can be misleading (I recently read an analysis that points out that even electronic component data sheets are marketing tools that have to be treated with circumspection by the engineers).

But, when that's all you've got to go on then that's all you can do.

Enjoy your bike.

And thanks for pointing out I overstepped.

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

genosensor wrote:

Darus is working on improving the existing analog voltage gauge and has said he will supply a kit to install after he's got it working to his satisfaction. It won't be a coulomb counter, but it should give enough information to know when you are down to 50% or 30% charge remaining. The current gauge doesn't unpeg until you are >90% depleted.

I'll be fascinated to see how he achieves this. I just don't think you can rely on an instantaneous voltage because the discharge curve on LiFePO4 is so flat. So, if he's not counting coulombs, I assume Darus has another idea up his sleeve? I think there'd have to be some digital processing in the system - and at that point I wonder why it would be better than counting coulombs?

__________________

John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas. No Worries." - JDH, CuMoCo || "Make Volts Not War" - anon.

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Re: Test Ride of the ZEV Scooters

genosensor and anyone else owning any electric ride, can I ask a question? The "twitchy throttle" reports are, to me, more significant for the sake of slow speed maneuvering than taking off from a stop sign/traffic light, or accelerating while on the road. I often wonder how well an electric scooter can be controlled at low speeds...on my 250cc scooter, simultaneously applying a bit of throttle and some rear brake makes it pretty easy to control the bike while making a U-turn, or performing some other tight slow speed maneuver.

How well do electric scooters do at low speeds (geno, I ask this for both with and without the CA)? Is there a physical rear brake that can be used to help achieve fine control if you were to, say, try to pass a motorcycle license test which includes "the box" (ride a figure 8 in a smallish painted rectangle with feet off the ground) or the offset cone weave?

I think of electric scooters and electric motorcycles as being *motorcycles* that have a different power source, and I'm of the opinion that riding an e-bike needs to be approached like a motorcycle (clutches notwithstanding). Hence my question about slow speed maneuvering, which is part of the riding skill package IMO.

Thanks for any thoughts or experiences anyone can relate to my question!

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Re: Test Ride of the ZEV Scooters

These guys seem well primed for comprehensive review of electric maxi-scooters:

http://www.motorcycle.com/categories/electric.html
http://www.motorcycle.com/manufacturer/2010-ebike-shootout-89839.html

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- brent

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Re: Test Ride of the ZEV Scooters

I can get a fair idea of my ZEV's state of charge from the Cycle Analyst's digital volt meter alone.
I've had to this early on when I mistakenly reset it.

96V is hot off the charger
94V after a few hours balancing (100% charged)
90V (approximately 25% charged under no load)
80V (approximately 25% charged under full load)

An analog gauge could display the pack voltage such that full scale was at 95V and no charge remaining was considered about 75V.
You'd need a voltage regulator, a voltage divider and a couple of op amps. (for amplification and low-pass filtering)
All that would easily fit into the back of the gauge itself.

The challenge in using it would be being separating the effect of voltage sag under load from state of charge.
Not very accurate, agreed, but likely to be simple and reliable. (Stateless too!)

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- brent

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Re: Test Ride of the ZEV Scooters

The most efficient way to throttle modern digital motor controllers is to control the percentage of time the controller is full "on" vs. full "off" very rapidly. This is termed Pulse Width Modulation or PWM. The trouble with this is that the resulting throttle control has a very different feel than what we gas motorcyclists are used to. First, you've got most torque at 0 RPM. Second, for any given PWM throttle setting there will be a speed the bike will want to accelerate to and maintain (more like setting your cruise control than cracking open a gas engine's throttle) These effects get more pronounced as the electric bike gets more power to weight. For a 200watt E-bike, you could get by with a two position switch for a throttle.
Don't try this in a Tesla Roadster.

The PWM throttle controls the voltage available to the electric motor. This determines its final speed and will usually result in rapid acceleration to that speed. However, we really want the throttle to determine the force output by the motor, so that the rider can smoothly vary acceleration to adjust their speed.
This type of throttle control typically requires more processing because the PWM throttle required by the controller electronics must be dynamically modulated to maintain a constant number of amps (not volts!) flowing through the motor for any given throttle setting. Amps are proportional to torque, volts to speed.

All of the Chinese scooters and the US made GPRS I've ridden seem to implement a direct PWM throttle.
The Vectrix is the only E-scooter I've ridden that clearly has a (very nice) torque throttle.
I've never ridden a Zero or Brammo. They most likely have torque throttles as well.
My experience with my ZEV7100 has convinced me that the $160 Cycle Analyst can be used to add torque throttle control to most any small electric vehicle lacking one, if you are geeky enough to configure it. In any case, once you've got control of torque output, low speed maneuvering is even easier than on a gas bike as there is there's no clutch to feather (centripetal or otherwise). Torque response is linear right down to a stand still. So, the DMV test should be a breeze.

The ZEV's controller does cut out the instant the brake lights illuminate. Energy is still precious on these early E-motos. No point wasting it heating the brakes. Further, the quickest way to burn up an electric motor is to force large currents through it while it is stalled.

The first few times I tried stopping on a hill to insert my card key into my office's garage, I could not get the bike moving again. The trouble was, I was instinctively trying to throttle up with the brake on to keep from rolling back down the hill. I finally learned to simply throttle up with the rear brake firmly engaged, then release the brake quickly and completely. The bike rolls back an inch then climbs. Remember, there's immediate torque at zero RPM!
It was hard for my hands to remember that, even though I knew it well, intellectually.

Hope this helps.

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- brent

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