Need help sourcing/building replacement battery pack

dhabicht1

100 µW
Joined
Jan 25, 2012
Messages
7
Trying to help out one of our local veterans he has a Polaris Strive ST bike with a dead battery pack. I repair ultrasounds not bikes but said I would try to help. I have disassembled the battery pack and it currently has 8 cells which are LiMn2O4 type from Victory Battery Each cell is spec is Nominal Capacity and Voltage of 6ah 3.7v Style CC/CV model # is V-LMO-D325660A I have tried to find these been have been unsuccessful. If anyone knows if I could rebuild this with more commonly available cells that would still work with the controller and charger I would be greatly appreciative
 
Depending on the space available you could rebuild the battery with 18650 cells. The ~ 29v 8 series could be matched by paring groups of 3 or 4 18650 cells in parallel to replace each of the 8 series cells you remove.
If the battery management system (BMS) and charger are working correctly the repair should be seamless.
There are many threads here on ES debating 18650 cell choices and battery pack assembly.
As a Vet myself I thank you for trying to help another.
 
How big is the space or a picture of the battery size. https://endless-sphere.com/forums/viewtopic.php?f=31&t=87434 maybe this will help ?
 
Are you sure the batteries are bad? If the pack sits around for too long without being charged, many times the BMS won't have enough voltage to turn itself on so it fails to charge. A low current charge that bypasses the BMS can bring the cells back up enough for the normal charger to work.
 
Thanks for all the suggestions, I think the bike has sat for awhile, some of the cells are reading a good voltage and others aren't. I'm going to try the low current charge on the bad cells and see what happens. I'll post back once I have done so.
 
Well I set up a 8S2P pack with 18650's but now I have really no inkling on how to set up the BMS. The current BMS has 8 wires for the 8 cells in the old setup. I now have 16 cells. The only wire I know for sure is the white which was soldered to the Main + Red wire. The rest not sure how to wire it to my pack.
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Assuming that I see the minus and plus correctly on your green 18650 pack, then I find that the connections/wires corresponds as I have numbered them on your pictures.
batt3.jpg

batt1.jpg batt2.jpg

I hope this may help you a bit.
 
Thanks for the reply I will give this a try when I get back in town. I really want to get this bike back to my friend by the 4th of July. I think it would be a perfect celebration of his service.
 
So far so good, Dean is going to be one happy camper when I bring this back to him. Thank you to everyone who helped me figure this out.
 
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