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[iSurgeon]

Doc the only slight issue I am having the last two mornings after being on the charger overnight the battery voltage is at 57.8v. It I unplug the charger and plug it back in it will charge for about 5 more minutes and be back at 58 or 58.1. When I charge at work it goes back up to 58.1v.

 I was thinking of dropping the front of the battery down this weekend to check the cell voltages at the bms connector to make sure the bms is keeping them balanced. Any thoughts or recommendations on the issue?

Thx,

Tommy.

[trikester]

I won't answer for Doc but my guess is that  since it is sitting longer after the charger turns off at night the battery drops to the 57.8v level. In the day, after work, it has not sat as long after completing the charge so it has not had time to drop as low as during the night. Temperature differences between the day location and the night location could also be a factor.

Trikester

[iSurgeon]

Thx Trikester that sounds logical. I just assumed since the charger still pulls about 5 watts from the wall after it was done that it would keep it topped off at 58.

As an experiment I charged it all the way after I got home yesterday and then left it unplugged all night.  It was at 58 when I unplugged and the same 57.8 this morning.

I'm still going to test the cell voltages this weekend to make sure they're balanced.

I think if I remove the charger and pull the bolts out of the front of the box I can lower it enough to remove the front panel and get to the bms connector. Is there any way to interface with the 2010 zero bms with a laptop? I've seen people talk about it on here with 2011 bikes but the don't mention what type of cable and software is used. 

[trikester]

I can't answer the question about interfacing.

But about the charging, according to what I've read from Zero, the charger shuts off at full charge and then looks at the battery every 72 hours and turns on again when needed. If my FX has been sitting a while since reaching full charge I'll unplug and plug back in to top off, a little while before starting a ride that i think may take a lot of battery capacity. However, as others have said on this forum, that "top off" goes away quite rapidly when the ride starts.

Trikester

[hungff77]

Congraz iSurgeon. You did a very nice job. I also have an 2011 XU, and also planning to do the same. The only thing is I am not too familiar with the electrical stuff. But according to your post, it seems it is pretty much a plug-and-play swap. I am just wondering did you need to do any special tweak to make it works with Leaf Cell? I also wonder will I need to do anything with the delta charger and the original gauge to make it works with the leaf batteries.

[iSurgeon]

I wouldn't call it plug and play but it wasn't that bad.  The cells have the same nominal voltage as the molicels so the bms gauges and charger  work great as is. The most difficult part was the bms individual cell wiring. I put the new battery next to the old battery on the bench and moved the wires over one at a time. Took a bunch of pictueres and tested voltage a lot to make sure I had it correct. I also tested the voltage at the bms connector before and after to make sure it was the same.  The rest is just making it fit and make it neat and safe.

[Endoboy]

Very interested in trying this out. I got a 2010 Zero S last month, too, and the batteries are pretty much shot. They cut out under hard acceleration, even when fully charged. It's only got 2k miles on it, but I'm pretty sure the previous owners didn't follow the required procedures for proper battery life.

So, do you have any more feedback on how yours is working now that you've had some time to run the new Leaf batteries for a while?

Also, do you know what the fully-charged voltage numbers were for a new mollicell pack? When I did the math, seven Leaf cells came out to 53.2 v, fully charged, according to their specs. If the original cells were 60v, wouldn't that mean that the new pack would reach minimum operating voltage sooner, limiting range?

Thanks, and please excuse my limited knowledge about this stuff.

[iSurgeon]

The nominal voltage of the molicel pack and the 7 leaf pack is approximately 53v and bothe fully charged are about 58v. That's why the factory bms seems to work well.  My bike is running good still. I get between 20 and 40 miles depending on how hard I drive it and voltage sag is no longer a problem until the battery is nearly dead.

I don't think it's that the batteries were improperly cared for it's just that they are old and probably weren't the best choice for this application. My bike had only 320 miles and was always left plugged in and still had horrible voltage sag even when fully charged.

[Endoboy]

Thanks for the quick reply. It does sound like it will be way easier to stick with 7 Leaf cell packs, so the BMS system can still be used with one wire for each cell pack. And 20 to 40 miles will work fine for me.

You mentioned that the mollicells are rated at 300 cycles to 80%. Do you know what the cycle rating is for the Leaf batteries? I couldn't find that anywhere.

Now I just need to find myself an owner's manual for this thing. Zero never put them up on the web as PDfs, it seems. Odd, since the digital files surely exist, and it would have taken 30 seconds to export a PDF and ten more minutes to post a link on the site.

[jateureka]

You can access the BMS via the round multi-pin connector at the back of the battery box, at least that's where it is on the 2011 S. I think you need TerraTerm or similar hyper terminal software to read it. If you do a google search or similar you may find the threads in this forum or endlesssphere where doctorbass and others posted about accessing the BMS data.

[zap mc]

isurgeon, you have done a great job and given many people with older bikes a practical example on how to restore their bikes once the batteries given up. In many ways restoring an electric bike is more green than manufacturing one with a limited life span.
The early models were simple and light and it must be even better with 25lbs shaved off. Shame the mileage is still quite low though but your riding does look quite spirited!

[Drnknmnky13]

Hello all, I just picked up a 2010 S for basically free. I'm doing the research now to fix the dead battery pack.

I have a quick question. I want to run more leaf modules. Like 11. (20-40 miles is cutting it too close for me) would it be better to run the 4 extra in a series so the amps aren't too high? Or run them in parallel and the system will only take what is needed?

 Thanks folks. I'm very happy to have found this forum. I'm a big fan of alternative transpo. I currently run my 2 diesels on Biodiesel. I have an electric bicycle that gets a lot of use. However it wont do freeway speeds. Which is what I'm hoping to do with the Zero.

[protomech]

The motor controller for the bike - I believe AXE 4855 - only accepts battery voltages up to 60V max. Since the modules are a maximum of 8.4V per, you can only use a maximum of 7 modules in series before you need to upgrade the motor controller.

You could run a second string of modules, 7 series 2 parallel for a total of 14 modules in total to give you about 7 kWh. Or if the weight/cost/size is too high, you could disassemble the modules (internally 4 cells, 2 series 2 parallel) and build a new battery pack 14 cells in series 3 in parallel (equivalent to 10.5 modules).

Or you could replace the stock motor controller with a higher voltage unit. AXE 7245 accepts up to 90V DC maximum, the Agni95 motor accepts up to 84V. So 10 modules @ 84V is as high as you could go with that controller. You'd have a higher maximum motor RPM, so you could fit a slightly larger rear sprocket to give you a bit more power while still having a useful freeway speed. In this case you would need to build a new BMS to support the higher voltage battery, and replace the charger as well.

[Drnknmnky13]

Option 2 is what I was thinking of doing. 7 in series 2 in parallel.

Thanks Proto.

[kingcharles]

7kWh will give you a very good range!
If you manage to fit this on the bike please post your story because it will certainly inspire many 2010 owners to do the same.