XM-3500

Ok, order placed with John. Of course, at this point, I'm probably so far down the line that it'll be the 3rd container load, so I have a bit of a wait...

PJD
Don´t you need a negative wire from each cells as well to be able to measure them independently?

Johnny
Sweden
2 samples ordered....

"Don´t you need a negative wire from each cells as well to be able to measure them independently?"

In series connected cells, the positive terminal of the cell adjacent to the one being measured is connected to the negative terminal of the one being measures. So, the next positive wire IS the negative terminal. Adding a wire to each negative terminal would be redundant.

Also, the adjacent cells do not affect the voltage measurement in any way. Series connected cells behave as if they "don't know" the other cells are is connected to them. This is why balancing is needed.

Yeah, came to think of it the same second I pushed "Post Comment" stupid....

Ordered and payed for 2 samples 7 weeks ago, still no response to when they will be shipped...

OK, understand the pictures now - it is 20 cells - five groups of four which are interconnected as if they were 12 volt batteries.

Is there a wire from the positive terminal of each group?

But from the voltage you reported, it looks like your charger is a 19-cell charger, so your pack isn't getting fully charged. I don't think this bad for the pack like it is with lead acid, but you won't be getting full range.

Hi All,

MikeB - thanks for the order! You're my newest favorite customer! ;-)

Possible good news on availability - the production output from the factory is ramping up. If things progress as stated then folks should receive their scooters by mid to late September. This is an estimate not a guarantee. I'll keep you posted as I find out more. Rest assured that API (X-Treme) are doing all they can to get the scooters over here ASAP - they want to sell them to you even more than you want to buy them!

OK, there's no BMS :-( I'm going to compose a letter to Mountain Chen and to API today and find out what's up. I'll ask if the BMS can be provided to folks to fit after the fact. The cells are still guaranteed for two years.

There are 20 cells, and they are interconnected in groups of 4 - that's just a convenience for installation. The installation is very good - nice and compact and well secured. As Henry mentions there is room for another one or two cells at the front of the battery box (it's currently full of spacing material to hold the pack firm). Whether the controller will cope with the increased voltage remains to be seen.

The charger states "suitable for 20 cells" on the case. I've not yet measured voltages. I'll likely do that today.

Top speed - I'm now seeing indicated speeds in the 55mph range on the flat. A slight decline has the speed peaking around 58mph (indicated). A slight incline has the speed dip to about 51mph indicated. The inaccuracy of the speedo is going to be a percentage - not a fixed amount. Assuming 10% that gives real world speed of 50mph on the flat.

I stripped enough body work to get a shot of the battery pack - I'll post them later (but nothing much different than Henry has posted). I also have some pictures comparing the size of the bike with the XM-3000. One thing to note is that, unlike the XM-3000, with a little ingenuity this bike could be modified to have more storage space than the gas equivalent. There's a lot of free space between the plastic bodywork and the batteries (I'm not suggesting it can all be used because of thermal management issues - however, I suspect some useful amount could be "reclaimed").

I'm happier with my XM-3500 now - the top speed seems to have increased slightly (but more likely I just got a better test done). The ergonomics are fine. You can see the speedo and odo - but you have to peer over the top of the bars to see the LCD clock.

One thing I'm finding is that it's harder to keep say a 35mph constant speed. A couple of reasons for this (1) an electric motor has no "engine braking" (unless set up for regen - which this bike isn't) and so is more susceptible to speed up on slight declines (2) because there are no gears the throttle is pretty sensitive to try and get a 35mph speed. It's not awful - it's just something to learn. I wonder if the Vectrix guys have the same issue?

Hmm, no Regen, and no BMS. Both were nice selling points, I'm a little disappointed (but not surprised).

Any idea how much juice the bike provides at 12 volts? I'm thinking about extra lights for visibility, both front and rear, as well as a possible horn upgrade. The lights would be superbright LEDs, so they won't draw much, but my preferred horn is a monstrously loud Stebel Nautilus Compact Air-Horn, which draws ~18a for the 12v model.

Also, I'm going to want to install a Givi case on the rear. Is the Givi universal mount gonna work?

18A for a horn? No, I doubt the DC-DC is going to handle that too well.

Not sure if the Givi universal mount will work - but I suspect it will.

As far as no BMS goes - don't give up hope yet. I'm hoping to get X-Treme or the factory to provide one.

And now, a drum roll please....

My first range test is in. I rode for 77 km (48 miles) at a mix of about 70% out of town at speeds around 50mph and 30% in town at speeds around 35mph. The low voltage cut out was just tripping in on the last quarter mile.

So, with 48 miles before LVC at mostly top speed I'm very comfortable saying 40 miles "real world" range.

See, it's not ALL bad news.

Mr. John you are the man! Thanks so much and I am so grateful that you are putting the pressure on the manufacturers for the BMS, please let us know if there is any thing we "plain customers" can do to
help out with that all important issue? Mikie

Oh guys, no BMS on pricey batteries? That makes me so nervous. At the VERY LEAST spend the $20 to buy LM431s and a large value 1% accurate resistors. It will prevent the batteries from overcharging, balance them out over time by preventing one battery from receiving charging current while others do. It won't make sure each battery is charged like a real BMS will since your charge will still turn off when the pack voltage hits the target, but from what I've read not charging lithium batteries to 100% extends the life.

If you don't feel like making the circuit, I'll build it for $30+shipping. I think $10 for an hour+ of my time makes it worth it for me. Just give me a week to receive the parts build it and ship it. As usual, I'll post the circuit and fellow tinkerers can improve on it. Just e-mail me if you're interested.

tschaff_at_gmail_dot_com

Let's at least give X-Treme and/or the factory 24 hours to respond to the BMS question. However, please do post the circuit - I'll also email you.

Thanks for the offer - it is appreciated!

Ok I measured the voltages this evening total voltage 66.8.

I numbered the batteries starting from the front left as:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
17 18 19 20

Here are the voltage readings (using a Radio Shack Multimeter Cat. No 22-809):
1 - 3.33
2 - 3.33
3 - 3.28
4 - 3.31

5 - 3.32
6 - 3.39
7 - 3.49
8 - 3.49

9 - 3.32
10 - 3.34
11 - 3.32
12 - 3.37

13 - 3.31
14 - 3.31
15 - 3.30
16 - 3.29

17 - 3.30
18 - 3.28
19 - 3.29
20 - 3.29

John-- great work and thanks so much for the first "real world" test. I went back to the page that listed all the features of the Bike that I have already laid out $4000 to buy and I am still waiting for.
It states among all the other features that are obviously present in your bike the following:

Digital Protected Water Proof Controller With REGEN
Thunder Sky Smart Charger With BMS
Rear ABS, Front and Rear Disk Brakes {are these present & part of this bike?}

thanks for being our consumer advocate, "what goes around comes around"
Mikie

I think it will be even more interesting to see the voltage readings of the individual cells after a long ride.
Thanks the the information so far it really helps.

Eric Fisher
www.SiliconeBatteriesUSA.com

Thanks Henry! This is great info.

Looking at the Thundersky DS for the 40AH battery, it looks like it is only reaching 50% max charge. Not wanting to overcharge and lower the life of the battery, it appears a final change voltage of 3.75V will give 70% capacity. I am thinking the charger itself needs to have a higher voltage cutoff as well as some form of BMS per cell (possibly sparc's idea with a turn-on limit set at say 3.8V worse case and the charger set to cutoff below a string of 20 of these circuits such that its max cutoff is just below the sum of all worse case MIN turn-on of the BMS clamps so you don't accidentally get all the BMS clamps turned on and the charger is still chugging away!).

Hey sparc - I assume the 431 is set to turn on some clamping device that will bypass the charge current from the cell. Thinking the charger is a 10A output, the bypass circuit will have to handle this current so the 431 needs to drive probably a MOSFET with a series power resistor. Keep us posted on what you come up with.

P.S. Hey John - also let us guinea pigs know what you hear from API/Xtreme/Mountain

Thanks!

Ok I measured the voltages this evening total voltage 66.8.

I numbered the batteries starting from the front left as:
1 2 3 4
5 6 7 8
9 10 11 12

19 - 3.29
20 - 3.29

better measure the voltage after 100-200meter riding ..then it would much more balance.

Float charging voltage is not accurate.

Hi Mountain - for Li-Ion, you really need a BMS on each and at least every 3-4 batteries. Why does the XM-3500LI not have BMS when it should? It is also stated in the spec and details that theit does (and one thing that helped me decide to get this bike)?

You may have balance now but as the cells age they will slowly become unbalanced and there is nothing to prevent that unless you have BMS. Also having cells start to unbalance will cause faster aging on the "overcharged" cells.

Also, what about REGEN? This would help when going down slopes to slow down the bike (and get something back). Again, stated in the spec that it is supposed to be there.

See Tracy's post on http://visforvoltage.org/forum/2868-modifying-mountains-controller

we can do REGEN,it is not difficulty on technology,but it is useless,simple is more reliable.

Re BMS,we have some technology secret can't be post on forum,but Xtreme will do warranty for Lithium battery,don't worry.

Better test the voltage when drop a bit after fully charged,this would be stable state.

On the next V server we really need a wiki. It's so hard to keep track of data through all these threads.

Yes Eped, you're right on all counts. I found the wheel was already built over on endless sphere: http://endless-sphere.com/forums/viewtopic.php?t=2387 by another guy who also answers to Jeff. He even has the isolated output to detect if too many shunts are turned on.

It does look like undercharging the batts is their safety plan! The plot thickens, now someone has to open the case up and see if there is anything user adjustable in there or contact the manufacturer.

On that link you can download the schematic. (Actually more of an open source evolution) My only complaint about it is there is no redundancy. If it breaks it won't shunt current, and unless you have another way of monitoring cells you'll never know. This was only meant to be cheap temporary solution until something better comes along (in one month I hope!)

--Jeff

P.S. I was telling my gf (the one on my avatar) about my GreenBMS. She's a certified EE, so we talk about these topics for fun. She thought it would be funny if I answered my posts on V using an account that has the mirror image of my avatar!!!

She's disappointed with the XM-3000 range at full throttle, I'm trying hard to convince her not to buy a gasoline scooter.

Re BMS,we have some technology secret can't be post on forum,but Xtreme will do warranty for Lithium battery,don't worry.

I was wondering about that so the BMS is there then? I can think of how you might be doing this and will not discuss it here; just stating it is here will answer my question.

I am a little confused are these all the same scooter as the XM-3500:

EM3500 http://www.iloveebikes.com/em3500.html
VK 2800 Xiamen ZAP EV Manufacturing Co.Ltd

She's disappointed with the XM-3000 range at full throttle, I'm trying hard to convince her not to buy a gasoline scooter.

What range does she need? I'm considering a LiFe option in the XM-3000 size of bike (also, Liberty above states the availability of a LiFe model).

Would folks want to pay $500 to $1000 extra for a lithium option in the XM-3000 size of bike?

There is a section in this thread from John about a LiFePO BMS from
http://www.paktrakr.com/
That will handle a lot of batteries.

Unfortunately the bikes do not have a BMS. During factory testing it turned out that the BMS that was planned for was not reliable and, more importantly, during long term testing (9,000km so far) these cells appear stable without BMS. The warranty of 2 years still applies. Bear in mind that if the batteries function properly for 2 years (while under warranty) it is highly likely they will continue to function for 1,500 cycles as stated.
I apologize for the lack of BMS. Functionally, the bike still performs as advertised, 55mph indicated top speed and 45 mile range. For those that want to fit a BMS I will research available aftermarket BMS's suitable for a 20 cell LiFePO4 set up.
For folks who bought from me I will provide the BMS at a discounted price. But TS don't give any warranty if BMS put into use.

OK - those last words from Mountain Chen were actually written by me. Apart from the very last sentence. I was working with API and Mountain to understand the issue and was planning on posting something. As a courtesy I sent them my intended post.

To avoid repeating what's above which describes the "why" - I'll take it from the part where I started using the word I which applies to me (I don't know if Mountain wants it to apply it to him as well).

----

I (as in John Harding) apologize for the lack of BMS. Functionally, the bike still performs as advertised, 55mph indicated top speed and 45 mile range, and the battery warranty will still be honored.

For those that want to fit a BMS I will research available aftermarket BMS's suitable for a 20 cell LiFePO4 set up. However, fitting a BMS will invalidate the warranty, this is because the battery manufacturer (Thundersky) has no control over the suitability of a third party BMS fitted by a third party installer.

There doesn't seem to be a way around the warranty issue, so customers appear to have a choice:
1) use the bike as is and rely on the warranty, or
2) fit a BMS and rely on it's function to extend battery life.

Note also, that folks who change the charging profile of the charger will also invalidate their battery warranty.

Above all, please do remember that the bike does perform as advertised (which seems to me to be the most pertinent issue). 55mph indicated top speed and 45+ mile range at 50mph and has a 2 year warranty on batteries.

There is a section in this thread from John about a LiFePO BMS from
http://www.paktrakr.com/
That will handle a lot of batteries.

Again, let me point out PakTrakr is not a BMS. It simply monitors battery levels it does nothing to balance battery strings. However, another user pointed out that the maker of the PakTrakr is also working on a BMS.

What range does she need? I'm considering a LiFe option in the XM-3000 size of bike (also, Liberty above states the availability of a LiFe model).

Would folks want to pay $500 to $1000 extra for a lithium option in the XM-3000 size of bike?

I think 40 miles minimum, and without killing your battery lifecycle. Yes, I am sure people will spend $500 for that option $1000 is pushing it, $1000 in gasoline goes a loooooooooooong way on a scooter.

I really wish we could all get over using the term "indicated" mph!
I don't recall seeing Dealer ads that say "indicated" MPH; they generally say "Top Speed XXMPH".
I have to ask what the States DMV's and Attorney Generals will think of the term when some disgruntled customer reports the discrepancy and initiates an investigation.
I think we would all like to avoid losing these bikes in the market, but that's what is at risk if the Marketing hype continues to diverge from the Actual.

This is a call to all Manufacturers, Distributors, Dealers to advertise ACTUAL MPH(GPS), not "indicated" MPH.
Same with the BMS discrepancy; how difficult would it have been for the manufacturer to notify dealers when they shipped that there was no BMS, or if there IS one, what type it is.
Truth in advertising; standards and full disclosure are what I'd like to see.
I understand that the Dealers and Distributors must rely on their manufacturer to give them accurate information in the first place; so truth in advertising must begin with the manufacturer.
I feel like we're encouraging bad behaviour by accepting scanty or misleading information.
The manufacturers must be made to understand that we expect better, or we will continue to be misinformed by them.

Indicated MPH is wrong, it is virtual MPH, it means nothing.
The practice is simply deceptive and unethical. IMHO.

Ross

Ross,

"The practice is simply deceptive and unethical. IMHO."

You might want to either drop the H out of that last abbreviation or change your presentation style. ;-)

Your solution is actually very simple. Don't buy one of these bikes. If you're unhappy with the situation keep your money in your pocket. Hopefully, (in a few years maybe?), the electric motor scooter market will be 1% of the size of the motor scooter market, at which point it will be far more mainstream than it is today. At which point folks will be competing with the billion dollar companies like Honda and Yamaha. Until then please realize that you're dealing with an early adopter market - there are going to be road bumps along the way. Those who want smooth sailing then I suggest they buy a Honda. Seriously folks - even when Honda started doing business they were lets say "sub optimal".

The reason I use indicated is so that folks don't come back complaining that the speed is different. In my Ford Focus the difference is about 5%. Sure, 5% is better than 10% but it's still not accurate. I believe that the speedo is accurate enough to meet the specifications set forth by NHTSA. I've even seen claims that the NHTSA doesn't actually specify speedo accuracy (I find that hard to believe). I'm currently checking the NHTSA stuff.

Personally, I simply use indicated to try and be as upfront as possible - if you're going to complain about my truthful statements then I can easily drop the word.

BTW, how accurate is your GPS? Does it have WAAS? What's it's satellite acquisition time? They differ as well you know. I guess I just want to point out that what you've arbitrarily stated as the gold standard could be debatable.

"Indicated MPH is B.S., it is virtual MPH, it means nothing."
And how do you figure that out? Once we determine by what amount the speedo is wrong it becomes a simple matter to know the exact speed. If you go do a google on "speedo accuracy" and you'll see this isn't unique to our market.

The BMS situation is much more of a real issue than the speedo. It is unfortunate and it is true that we should have been informed. We're working on improving those lines of communication.

At the end of the day if you want to jump up and down and rant about "BS" and "Marketing Hype" then there's plenty of ammunition for you to support your cause. However, if you take a step back and look and see whether this year's situation is better than last year's I think you will see that the electric motor scooter market is making progress.

I probably shouldn't have responded to this - but please know that we are improving. Again, if you're not at your own personal comfort level then you really should just wait. However, a lot of folks would rather have the chance at having this product "warts and all" right now.

the Bike that I have already laid out $4000 to buy and I am still waiting for.

Rear ABS, Front and Rear Disk Brakes {are these present & part of this bike?}

Mikie - who did you buy from - they shouldn't have charged you any money yet. Yes, the bike does have ABS front and rear - it's the lower cost style of ABS that limits brake caliper forces rather than the more expensive type the actively checks for a locked up wheel and then releases and reapplies the brake. The style of ABS on this bike is common across several other gasoline powered models.

>>I feel like we're encouraging bad behavior by accepting scanty or misleading information

Ross,
I do not disagree with your facts, but I think the context , and perhaps relative judgment is not one I agree with.

I have actually started a few businesses with products that were "bleeding edge", it is often far from pretty.

All, in all, I give Mountain and the US distributors fairly high marks for product and delivery . Was it perfect, no. But we weren't paying for Vectrix, and we knew the game when we joined.

As far as truth in advertising, I know the tooth paste and new cologne did NOT get women to fall all over me..like the ads said it would ! SO here in the states we make "purposefully" misleading lies about products all the time. I see the disparity from the advertised and the delivered products as being understandable given the price and the "early adopter" situation.

I have not received mine yet, and I "courageously" waited till the second wave to make SURE that there were no "major issues ". It does not sound like there is a line to return the products, so some disappointments, but for the first efforts, not bad.

I also think that this board does a great job of informing BEFORE you buy ...

Now the Z-20 guys, THEY have had some really major issues :)