New Vmoto E-max test drive

With the speed restrictor jumper removed from the controller, the old "German" E-max had a claimed top speed of 60 km/h - and would almost achieve it if a size larger tires were used. I upgraded mine to 60 volts, and 40AH Thundersky cells, which yields a top speed of 70-75 kph.

Haven't ridden one, but there's a lot of hype about them, for example a 90km range @ 45 km/h?
http://www.vmotoscooters.co.uk/products/e-max-110s/
E-max claim the silicon lead acid batteries are 85% efficient compared to a standard lead acids 65%
http://wnc.us/e-max/batteries.html

Now a GEL 60Ah lead acid battery will output 20A for two hours down to 10V (dead flat) = 40Ah, not the full 60Ah because of inefficient lead acid chemistry. The silicon version is 30% better (85/65 = 1.30) so will output 26A for two hours until 10V (dead flat) = 52Ah.
Therefore the maximum Watts available to power the scooter for two hours are 2496W (52A x 48V) say 2.5kW
The vmotoscooters website states maximum power is 2.5kW and max speed is 45km/h, so two hours at max speed using max power is 90km which agrees with their 90km range @ 45km/h specification...but the batteries will be dead flat (100% discharged) after 90km.

Dead flat batteries only last about 100 cycles. Of course a 100 cycle battery isn't economical to buy unless you have money to burn! To get the 300 cycles, the batteries can only be run down to 70% discharged, according to the e-max website. That reduces the range to 63km (90 x 0.7)
Further more 'real world' riding includes accelerating/hill climbing and extra rider weight 2 up, which probably reduces the range 50% to around 30km.

You can see why many people are using Lithium powered scooters now, with 1/3 the weight of silicon lead (the vmoto battery pack is 96kg!) and 100% battery power available, the range increases substantially!
With 60Ah Lithium batteries the vmoto would go 90km and still have a 1000+ cycle life @ 80% discharged.
Even if they cost 2 or 3 times more than the silicon batteries, they work out cheaper in the long run!

Hope this info is helpful!

Ross

The Emax 90s I had access to had a range of 40km@45kmh on its original 48v 40Ah Silicon batteries.

I later got hold of the 60kmh version of the Motorcontroller and motor, and installed a 48v 90Ah LiFePO4 pack.
Range improved to 100km@60kmh.

I'm quite surprised Vmoto are still bothering with silicon batteries, they must have quite a stockpile of the silicon batteries to get rid of.

Matt

Haven't ridden one, but there's a lot of hype about them, for example a 90km range @ 45 km/h?
http://www.vmotoscooters.co.uk/products/e-max-110s/
E-max claim the silicon lead acid batteries are 85% efficient compared to a standard lead acids 65%
http://wnc.us/e-max/batteries.html

Now a GEL 60Ah lead acid battery will output 20A for two hours down to 10V (dead flat) = 40Ah, not the full 60Ah because of inefficient lead acid chemistry. The silicon version is 30% better (85/65 = 1.30) so will output 26A for two hours until 10V (dead flat) = 52Ah.
Therefore the maximum Watts available to power the scooter for two hours are 2496W (52A x 48V) say 2.5kW
The vmotoscooters website states maximum power is 2.5kW and max speed is 45km/h, so two hours at max speed using max power is 90km which agrees with their 90km range @ 45km/h specification...but the batteries will be dead flat (100% discharged) after 90km.

If you consider things in Wh not Ah it gets worse.
Your calcsdont add up.
Max power would be for the motor/controller/battery combo.
mmm... 52Ah for similar size Pb-silicon-electrolyte....So thats for two hours 26A not 52A. So the battery would only allow 50min at 2.5kW as pulling 52A will reduce the Ah to less than 52Ah and the voltage will be lower too.

Dead flat batteries only last about 100 cycles. Of course a 100 cycle battery isn't economical to buy unless you have money to burn! To get the 300 cycles, the batteries can only be run down to 70% discharged, according to the e-max website. That reduces the range to 63km (90 x 0.7)
Further more 'real world' riding includes accelerating/hill climbing and extra rider weight 2 up, which probably reduces the range 50% to around 30km.

You can see why many people are using Lithium powered scooters now, with 1/3 the weight of silicon lead (the vmoto battery pack is 96kg!) and 100% battery power available, the range increases substantially!
With 60Ah Lithium batteries the vmoto would go 90km and still have a 1000+ cycle life @ 80% discharged.
Even if they cost 2 or 3 times more than the silicon batteries, they work out cheaper in the long run!

Hope this info is helpful!

Ross

If the $/Wh /kCycle was cheaper for a technolgy that would help it. Stay in the market.
But how often its used is important and the neusience of early ware and pack/cell changes.

Wow Antiscab, 100km at 60km/h

7c

Hi!

I am the happy owner of a 110S e-max (now owned by Vmoto) scooter since ~2.5 years and have recently exceeded 4000 km.
My weight is of ~130kg and, adding clothes and luggage I can say that my scooter carries 140kg regularly (nearly the maximum load of 150kg). I am riding it in city conditions so, including accelerations, hill climbing etc. - not ideal riding conditions. Under these conditions here are the ranges I have reached by going from full battery to automatic power cut-off (at 42V):
- average @ 20-35 deg. Celsius --> 60-70km;
- minimum @ 5 deg. Celsius (beginning of winter) --> 50km;
- top range, only reached once @ 42 deg. Celsius --> 80km.
The "boost" button was used only once or twice per charge.

So, I would say that, if one weighs 75kg and rides the scooter @ 25 deg. Celsius, even in city conditions, one can easily reach the range of 90km. If one does not exceed 35km/h on flat road and ideal conditions, I dare to say that one will exceed 100km of range, maybe going to 110-120km.

Another useful info is that, after >60 complete charging cycles, I don't feel any degradation in the range. It's true that I didn't make accurate tests in identical temperature conditions 2 years ago and now but the feeling is that the range is still stable.

Hope this helps.
Cheers!

I have just acquired an e-max 110s, from january 2009, with 4670 mms on the clock and original SLA batteries. First time fully charged ran 52 mms until the low battery warning came on. I am a 100 kg rider, and live in the foothills of the Pyrenees. Used the boost button a least a dozen times if not 24 times during this ride. As much as I would love to convert it to LiFePO cells, I cannot justify that at this moment... Happy.

I keep seeing comparisons in which real life life cycles of lead-silicone batteries are compared with estimated/advertised number of cycles of lithium batteries. What I'd like to know is: how many people are getting more than 300 cycles on their lithium batteries with no cell failures...? The more I read about problems with lithium (not to mention Vectrix NiMH!) packs, the less impressed I am with them. The Greensavers in my ZEV are giving me no problems whatsoever, while just about everything else (except the motor) is...

In the mean time I should have around 300 charge cycles on my 24 GBS 40Ah cells, but I mostly charge only from about 45 to 50% discharge, with only 3 or so full charge cylces. And all 24 appear to be as alive and well as GBS cells can be. But I know that I may be on the lucky side here...

I keep seeing comparisons in which real life life cycles of lead-silicone batteries are compared with estimated/advertised number of cycles of lithium batteries. What I'd like to know is: how many people are getting more than 300 cycles on their lithium batteries with no cell failures...?

My pack is up to 33'500km on the lithium pack, I have nominally 100km range (@50mph/80kmh continuous)

so thats effectively ~335 cycles, although the number of times I have actually plugged in is closer to 1000 times (I don't use the full 100km range all that often)

No capacity loss in that time

Our two experiences seem to be worlds apart,
I have yet to see a green saver battery (or any sealed lead acid battery in a scooter) make it past 100 cycles ( I traded in ~600kg worth of dead ones for the lead around 6 months ago)

Matt

I think that this is because with lithium packs the BMS and charger are doing most of the decision-making, while with lead -* packs the rider and charger are sharing the decisions, and people tend not to make good decisions reliably and consistently. The only lead batteries I've had die were cooked by defective chargers. I prefer having it up to me how long my pack lasts, rather than having to hope it has no bad cells and a really good BMS. I don't put a huge number of cycles on my packs - I figure the Lepton had about 170-190 cycles on it - but I'm not seeing a lot of lithium packs get past 300. Maybe it's just a case of people only coming to places like this when they have problems with their scooters...

L.B.,

The biggest problem with SLA's of any sort - including Greensavers, is that they come in 6-cell packages commonly known as "12-volt batteries". The cells in such batteries will become unbalanced no matter how carefully charged, and then after 150 charge cycles at best, a cell and consequently the whole battery will die from over/under charge and the whole battery ruined. SLA's are fine for standby-type uses, but were _never_ suitable for electric vehicle use - and their use as such has probably set back the whole casue of 2 wheel EV's by years becasue of the degree that users were ripped off by their poor performance.

The only solution to this problem is to use conventional flooded batteries that can be equalization charged - deliberately overcharged until all cells are balanced - gassing away some electrolyte in the process - which is then easily made up with distilled water. But such flooded batteries can't be used in a 2 wheel vehicle because of acid spillage if you tip the bike over. Or, if anyone makes them, use single-cell SLA's and a BMS, like we do with lithiums. But the price has reached the point that it is simply more economical in the long run to use lithiums and a BMS.

By the way, I have about 200-250 mostly fairly shallow charge cycles on my CuMoCo bike with GBS cells and with the exception of one bad cell, is performing well with no signs of degradation. My smaller scooter with Winston cells is running flawlessly after 14 months of calender life. The Winston cells performance is so consistent that I could probably do without a BMS in a 16 cell pack if I kept charging voltage to 57.5 volts (3.6 per cell) or so. The Chinese Lithium cells have improved dramatically over the past couple years.

"The biggest problem with SLA's of any sort - including Greensavers, is that they come in 6-cell packages commonly known as "12-volt batteries". The cells in such batteries will become unbalanced no matter how carefully charged, and then after 150 charge cycles at best, a cell and consequently the whole battery will die from over/under charge and the whole battery ruined. SLA's are fine for standby-type uses, but were _never_ suitable for electric vehicle use - and their use as such has probably set back the whole casue of 2 wheel EV's by years becasue of the degree that users were ripped off by their poor performance." - PJD

Sorry, but you're oversimplifying things. 12 volt battery packs can be equalized with a higher voltage end (or even beginning) of charge 'over-charge'. One of the reasons my Lepton's batteries went way past your theoretical limits is that the Zivan charger, instead of just stopping whenever it sensed the appropriate pack voltage, and refusing to do more than float charge until the voltage dropped again, went through a pre-programmed cycle whenever it was started, giving it at least a short "bulk charge" even when it wasn't needed. This let me not just add more charge before riding, it also EQ'd the pack, which is still usable after 11 years and at least 170 cycles, most of which were to 80% or so discharge. The people who got "ripped off" by SLA packs fall into three categories: those who abused the packs (usually by running them to empty, but also by leaving them sitting around nearly discharged), those who had defective batteries and/or chargers, and those who expected too much - running them down to 90% or more discharge for hundreds of cycles. I agree that SLA isn't the ideal battery type for EVs, but it's pretty clear to me that the ideal battery type, whatever it turns out to be, is not yet in use.

12 volt battery packs can be equalized with a higher voltage end (or even beginning) of charge 'over-charge'. One of the reasons my Lepton's batteries went way past your theoretical limits is that the Zivan charger, instead of just stopping whenever it sensed the appropriate pack voltage, and refusing to do more than float charge until the voltage dropped again, went through a pre-programmed cycle whenever it was started, giving it at least a short "bulk charge" even when it wasn't needed.

AGM's and the silicon batteries are of starved electrolyte design

an equalisation charge causes loss of the electrolyte which causes capacity loss - the batteries are usually damaged by the chargers not the riders.

loss of electrolyte causes reduced capacity, as well as increased internal resistance

this generally a trade off with the capacity loss from an imbalanced pack
It would appear the zivan charger you use along with your usage profile have got the trade off about right

170 cycles in 10 years is very in-frequent use indeed
with that sort of usage lead would indeed be better, the $700 extra for lithium would be hard to justify (even using a new bike would be hard to justify)

I would suggest that usage profile is more the exception rather than the rule?

once a single cell has lost capacity, than it can be finished off by a longer than usual ride

The starved electrolyte design of both AGM and silicon batteries mean they are resilient against overdischarge, but not cell reversal

That's why the battery first has to be damaged, or unusually imbalanced before you are able to damage it from discharging too far (you have you reverse a cell). Note: you can reverse a cell before it is depleted

most chargers including the cheap chinese one's the emax and x-treme scooters are shipped with will restart the full 3-stage charge process everytime you reconnect the charger

there is a danger in this implementation, particularly with chargers that have the cc stage above 0.1C, in thermal runaway (long story short, the gassing voltage falls with increased temperature, once it goes below the charger's threshold voltage it never shuts down)

the danger is greatest for batteries that are in daily use, as the heat generated within the battery is more than can be dissipated in the course of a day

That means on your average monday to friday commute, your battery is warmest on friday.

Matt

L.B.

What have been your experiences with lithium cells? I'm not sure what would meet your criteria for "ideal" but I have use both 40AH SLA and 40AH Thundersky/Winston cells on the same scooter, and the performance improvement is dramatic with the lithiums - twice the range, consistent voltage until nearly depleted and much less weight.

As Matt explained, SLA's cannot be equalization charged.

Let's see, bunch of responses to make...

I have no experience riding with lithium cells. I do read a lot about them, though, and just from reading this site and other forums it appears that using lithium is a waiting game: will a cell fail? Will the pack lose EQ? Will the BMS do something it shouldn't do? Will the BMS I was promised ever arrive? Aside from the 10 years I rode the Lepton, I'm on my third season with my XM-3000, with similar Greensaver batteries to the ones I have in my ZEV. I've had two ZEV chargers fail, but the little charger that came with the XM, and the batteries it charges? Zero problems, zero drama. (BTW, that one is a two stage charger, not a three stage. It will provide a very short burst in bulk charge mode when connected, proportionate to how long the scooter has been sitting unused, then go back into Float charge mode. Usually 3-30 seconds in Bulk.) There may be a lot of poorly constructed SLA batteries and chargers out there, but from what I've seen failure is the norm with even some of the more expensive Lithium batteries. You can put together a reliable off the shelf power system using SLAs for less than the cost of a Vectric charger. That's what my ZEV has, and it will apparently go as far as a Vectrix, too, assuming the non-driving bits of the scooter hold together long enough....

It's being *claimed* that you can't EQ an SLA pack, and the claim seems to rest on loss of electrolyte through the one-way vents in the batteries. It appears to me that you can indeed EQ the packs, and you just have to get a good balance between too much overcharge and too little. If you were right, J, my Lepton would have run out of juice during GW's first term. (I'm not a lucky guy, as you may have noticed, so I doubt I had a one-off Gem of a Lepton.) Even assuming that electrolyte gets 'sacrificed' during every single charge (which I doubt), using the 50AH gel(?) batteries now available for the Oxygen, and limiting DOD to 60-75% should be good for far more than the 150 or so cycles you claim as the limit - especially if used with a Zivan charger. My own feeling is that good 40AH AGMs would lose less electrolyte and thus last longer than gel cells. If the 50AH batteries are really AGMs, so much the better!(I also have a theory that riding on somewhat rough roads regularly will break up the larger sulphate crystals in the tougher AGMs, extending their life.)

Anyway, until I get factual responses (data, not claims or just descriptions of how batteries work) to counter my actual, real-world experience with SLAs, I'm going to stay with my position: that Lithium batteries are not the best technology for powering EVs, and that the most rugged, reliable technology available to do so, despite all the weight, reduced range, etc, is lead-acid, or lead-whatever-is-in-Greensavers. And I think that that's a shame. SLAs wouldn't have 'held back' the development of EVs if the alternatives didn't keep failing early (Evercel, anyone?), catching fire (turn your e-bike into a ROCKET with lithium ion batteries!) or just not working nearly as well as claimed if at all (Vectrix). It would also have been helpful if nearly the entire industry hadn't moved to China, but with these multiple recessions we keep having I doubt there was ever a path to widespread adoption.

The ultimate irony may be that the Chevy Volt, which started as nothing more than vaporware (golf cart innards painfully, slowly dragging around a Camaro concept car) may end up, along with the Leaf if it doesn't prove glitchy, saving the industry.

Hey, hope you are well, just bought 2 of these and they are great, we have the 120s, which is great, mileage is getting better and better as we use them, did you get a bike, best wishes Mark

Hi there!
I'm coming back to share with you an unfortunate experience that I finally solved (with a little help from e-max tech support). I'll tell it the reverse way, from cause to effect, as it's easier to follow.
It starts from the power tri-phase cable that goes from the controller to the motor. That cable is posed under the seat, between the battery box and a piece of pipe belonging to the frame (chassis). Due to that positioning it is slightly tensed and subject to tensions during riding. What happened to me was that the thick rubber insulation of the cable started to fissure, leading in a few months to complete rupture that allowed the insulation to slide up along the cable and leave the 3 wires only with their thin plastic insulation. Now, because of the vibrations, the wires repeatedly hit the battery box (connected to the ground) until both the paint on the box and the plastic insulation of the cables broke (were "washed" off). At that moment I got naked iron (battery box) facing naked copper (wires) with some air between them. So, it is easy to imagine how, when passing through a small hole in the road while accelerating (voltage present on the wires), those 2 touched and my scooter was dead. What happened? You know the safety switch of the side stand, don't you? The one that cuts off the controller when the side stand is out and prevents you from starting the scooter accidentally ... Well, when one of the tri-phase wires touched the frame (ground), it "hit" that switch with a nice high voltage that reached to the processor of the controller and "burnt" it in the way that it (the controller) "felt" that the side stand switch was always on. From that moment the scooter wouldn't move. The solution was to replace the controller as it is unrepairable.
So, my advice to you, e-max users, check your thick cable below the seat for any cracks or fissures in the insulation and tape it up before the copper reaches out ...
This happened to me after more than 1 year of riding and took ~2 years and 3 controllers to figure it out. Because the short circuit happened only at a certain vertical move of the scooter, caused by a certain size of hole in the road, I could ride it for months before it happened again.

Hoping that this will help someone to save his/her controller ...
You have my best wishes!
sumo1

Scary stuff, sumo1, but a good summary! It is most important that all cables in the scooter are securly fastened to frame or swingarm bits (with cable ties), and were flex is necessary (at the swingarm pivot or the steering head for instance) a non-fastened loop of cable long enough to allow full suspension or steering travel without stressing the cable. Then such dangerous and malicious faults should no longer occur.