What happened to my battery

I have not been riding much lately. I recently receive some Momentum wheels and Boardnamics gear drive. I installed everything and went to test it and the board would not turn on. After troubleshooting, it looks like my battery fully discharged. Several p groups are at 0v and a few are around 0.7v. The 10s4p pack in total is at 3.7v. The board loop key was removed. I have a charge only bms that is connected while the loop key is out so I can charge when the board is off. I am gussing this is the culprit. I have never had significant battery drain in the couple years I have had the board when it is stored like this. Is this the bms and if so, should I have had it wired to disconnect the bms when not being used? I am assuming the battery is toast. Any recommendations on a battery vendor?

This is very weird.

I would not blame the bms, but what type of bms do you have?

This one i got from @thisguyhere

Just a basic DALY 10s, they are usually pretty reliable and cheap to get

But odds are there’s an internal short in the parallel groups, as in some cells have gone bad, if there was a load then all the cells would be dead

That really sucks. That’s a reliable BMS too. :thinking:

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Add your location to your profile. :wink:

Just updated. Oregon.

@DuckBatterySystems or @Skyart

It has been a while since I have been battery shopping. It looks like p42a are the cell of choice now. This pack is a 10s4p 30q. It looks like a 10s3p would be equivelent or a little better. My issues is I only have about 15" x 6 3/4 and 1" of depth to work with. Can a p42a pack fit?

Your current pack looks like it only fits because it lacks insulation :person_shrugging:

I only have about 381mm x 171mm and 25.4mm of depth to work with

You’ll have to ask a battery builder what they can fit in there. There are also P26A and P28A cells from Molicel which are 18650 form factor.

Also give precise metric dimensions on what your space is, especially the depth in the middle. Often it’s lower than the depth on the sides due to deck concave.

The current pack is 3d printed nese battery holders. It is currently torn apart because I was troubleshooting. It fits because they are 18650 cells. I am not sure if 21700 cells would fit in the space. Insulation on a normal pack should be slightly thinner than the plastic holders I think.

Seems like enough room for a 10s3p flat pack

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Not very accurate, looks like nese modules or something similar. Should be plenty of space for a small space 10s3p

If you can get an accurate depth measurement in milimeters that was more precise than 1" it would be much easier to help. I was somewhat comfortably able to put a 21700 pack in a 29mm deep enclosure.

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Yeah I didnt look that deep into it. I saw “18650 pack in a 1” deep enclosure" which is very hard to do.
Also the balance leads all over the place

This is cake :sunglasses: 1” sooo deep lol :laughing:

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Yeah I don’t know what they’re talking about, 1 inch is massive, perfect size even.

What’s this inch thing you keep talking about? Are you talking about a Thumbwidth :tm: ?

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