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[eyeinsky]

Has anyone installed the new ZF2.8 battery in the older frame X,UX,FX? I imported some picture in to CAD just to compare the dimensions. Here's what I found. We probably could get one battery in there but not two.



Cheers Jerry

[eyeinsky]

Here's the Battery I will be adding to the bike this winter. It will be mounted it on the front of the bike at charger location. This should give me a total rating of 3.5KW /60 ah 58v.

[skeezmour]

I don't think those cells will like the draw that bike can do.

[eyeinsky]

At this point the bike draws on long hill about 75 to 80 amps. With two batteries paralleling that should be just over maybe 40 amps per battery. The BMS is rated for 60 amps continuous.

Jerry

[protomech]

Current splitting between the two batteries will depend upon their internal resistance. The cables, or wires, from the DiamondPower battery look pretty thin.. so maybe you are lucky and it has high resistance.

If you crack open the throttle on the XU at 30-40 mph it will probably pull 200 amps from the combined battery. I believe you can tune the controller to limit maximum current, in case the current split would exceed the 75 amp limit on the secondary battery.

I assume you will charge the batteries separately. How will you ensure they are charged to a level voltage before connecting?

XU battery is 14s ~3.0v to 4.2v. Not sure about lower limit. So total voltage range 42v to 58.8v. This is 2.8v to 3.92v for your lifepo4 cells.

This is the battery pack?
http://www.ebay.com/itm/48V30Ah-1500W-E-Bike-E-Bicycle-scooter-Waterproof-LiFePO4-Battery-and-Charger-/121176666496?pt=Cycling_Parts_Accessories&hash=item1c36b13180

Picture 4

Professional Waterproof and Dustproof connectors

Connect the battery to your ebike controller or your device

Max rated current: 52A (6mm2, AWG10)

Conventional rated current: 30A

Looks like the cells are limited to max 2C discharge (60A), BMS is limited to 60A cont 75A max, connectors are limited to 30A cont 52A max. I would recommend at least replacing the connectors to ensure they do not overheat.

[eyeinsky]

I was going to charge with one connection both battery connected in parallel with the delta Q. At this point I have monitored the charge and noticed the BMS in the ZF will cut voltage at 58V with both batteries connected it would be approximately 8 amp per battery the BMS on the supplement battery would balance these cells but I would rely on the ZF battery BMS to cut charge operation.

Ultimately I would upgrade the connector to something in the 100 amp + range.

Still working out some of the detail and i appreciate the really good input and welcome as much as willing to offer. I would share this to an other interested adding little more range to these lower KW bikes.

My question would be to you all, will this work?

Thanks Jerry     

[protomech]

I believe DoctorBass has done something very similar .. building a LiFePO4 pack to run in parallel with his 2011 battery.

http://electricmotorcycleforum.com/boards/index.php?topic=2705.msg11962#msg11962

I'd love to see some solutions for updating the molicel bikes to a more modern (and higher lifecycle) chemistry. My suspicion is that low-power lifepo4 (there certainly are high-power lifepo4, like doc's a123) will not be satisfactory in a small battery .. but I don't have any real-world experience to back that up with.

If your objective is to tinker with the bike and learn more about it, I say go for it! You'll definitely learn about the bike.

If your objective is to pick up some more range, I would consider upgrading to a larger Zero.

[Doctorbass]

I have 2x 2009 MX that i got for great cost and that i will replace the deffective battery with my 2kWh LiFePo4 A123 battery. This will be 40Ah on 16s2p A123 pouch and same voltage span as the 14s Molicell from zero. same end of charge voltage and same LVC.

Each A123 20Ah pouch can take up to 400A burst so my 2p setup can really do 800A burst but will be limited by the dual 6AWG cables. so i would say about 500A total. I also have upgraded the controller to a 500A alltrax but i'll have to ensure to not blow the perm132... unless i install two in parallel...

This project will be for winter and i'm pretty sure that the performances of the LiFePO4 A123 battery will easy outperform the stock molicell made of Lithium Manganese that are sensitive to temp below zero celsius...

Even if you get some A123 thay would be a great solution but i have to agree with protomech, the ebay battery pack you found is not the best solution.

Doc

[eyeinsky]

I have 2x 2009 MX that i got for great cost and that i will replace the deffective battery with my 2kWh LiFePo4 A123 battery. This will be 40Ah on 16s2p A123 pouch and same voltage span as the 14s Molicell from zero. same end of charge voltage and same LVC.

Each A123 20Ah pouch can take up to 400A burst so my 2p setup can really do 800A burst but will be limited by the dual 6AWG cables. so i would say about 500A total. I also have upgraded the controller to a 500A alltrax but i'll have to ensure to not blow the perm132... unless i install two in parallel...

This project will be for winter and i'm pretty sure that the performances of the LiFePO4 A123 battery will easy outperform the stock molicell made of Lithium Manganese that are sensitive to temp below zero celsius...

Even if you get some A123 thay would be a great solution but i have to agree with protomech, the ebay battery pack you found is not the best solution.

Doc

Thanks Doc seen the video I like the A123 too, I just liked the ebay LikePO4 because of the complete system plug and play would fit the charge location give me some more range. If my stock pack was failed no brain er I would do the A123 cell swap like you did.

Cheers Jerry