Need help sourcing/building replacement battery pack

Batteries, Chargers, and Battery Management Systems.
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dhabicht1   100 µW

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Need help sourcing/building replacement battery pack

Post by dhabicht1 » May 29 2018 2:36pm

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

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Hwy89   1 kW

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Re: Need help sourcing/building replacement battery pack

Post by Hwy89 » May 29 2018 6:29pm

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.

999zip999   100 GW

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Re: Need help sourcing/building replacement battery pack

Post by 999zip999 » May 30 2018 3:31pm

How big is the space or a picture of the battery size. viewtopic.php?f=31&t=87434 maybe this will help ?

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fechter   100 GW

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Re: Need help sourcing/building replacement battery pack

Post by fechter » May 30 2018 3:55pm

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.
"One test is worth a thousand opinions"

999zip999   100 GW

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Re: Need help sourcing/building replacement battery pack

Post by 999zip999 » May 30 2018 6:20pm

What year is the bike. Has it been charged often or left the sit for over 6 months or so

dhabicht1   100 µW

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Re: Need help sourcing/building replacement battery pack

Post by dhabicht1 » Jun 01 2018 8:19am

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.

dhabicht1   100 µW

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Re: Need help sourcing/building replacement battery pack

Post by dhabicht1 » Jun 16 2018 12:53pm

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.Image Image Image Image

MrAlvin   1 µW

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Re: Need help sourcing/building replacement battery pack

Post by MrAlvin » Jun 18 2018 5:05pm

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
batt3.jpg (215.94 KiB) Viewed 274 times
batt1.jpg
batt1.jpg (45.97 KiB) Viewed 274 times
batt2.jpg
batt2.jpg (48.18 KiB) Viewed 274 times
I hope this may help you a bit.

dhabicht1   100 µW

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Re: Need help sourcing/building replacement battery pack

Post by dhabicht1 » Jun 18 2018 5:49pm

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.

dhabicht1   100 µW

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Re: Need help sourcing/building replacement battery pack

Post by dhabicht1 » Jun 21 2018 6:57am

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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