Rebuilding OneWheel Battery

[simey_binker]

Hello Everyone!

I've been battling this hypothetical build for a few days now, and I might as well pull in the hivemind to get everyone's opinions. This thread does spawn off my other thread about BMSs, but I'll start fresh to discuss the whole project.

I've got a OneWheel here, and I've gutted the battery enclosure. The inner dimensions are 215 x 150 x 30 mm (plus a little on the 150 side). And the motor controller can pull up to 30A at 14S.

If we start off with the standard 18650s, in the LG MJ1 or similar (3500mAh, 10A) I can fit the necessary 42 cells in the enclosure for a 14S 3P configuration (which gives me my 30A).

HOWEVER, this bloody BMS situation. Daly's standard 30A 14S BMS has the dimensions of 80 x 61 x 12 mm, and their "smart BMS" (which includes bluetooth) is a massive 128 x 66 x 18 mm. This is the same volume as an additional 7 cells!! Perhaps it has a bunch of features I'm not really looking to get into - but I'd prefer to have bluetooth so I can see all the cells.

Do you guys know of a reliable balancing BMS with bluetooth that is considerably smaller? How can I do this? You guys have good ideas? Make the enclosure bigger? Use different cells? Know of a good small BMS? Has everyone even had a good experience with Daly? Is it really necessary to have bluetooth connectivity? Or can I just install the standard one and trust it is doing its job? The OneWheel controller does have an app for SOC - so I will be ok in that regard.

 

[simey_binker]

I suppose, to clarify; all my fitment problems go away if I just use the standard Daly BMS. This one:
https://www.aliexpress.com/item/32878976763.html?spm=a2g0o.cart.0.0.566c3c00JGWt4S

So, does anyone advise against using this one? I take it that once buried away in the enclosure, I just trust that it is doing its job.

 

[djkhaleb]

Hey Simey,
Did you ever complete this project? I have an old V1 that I want to fix up that is toasted (assuming battery and BMS). I was looking at the same batteries as you.
ChiBattery https://chibatterysystems.com/upgrades/cbv1
and
JW Battery https://jwbatteries.com/collections/onewheel-batteries/products/jwv1-onewheel-v1-battery-upgrade

They seem pricey for only have 28 cells. I have experience making longe range FPV batteries but those are quite simple and don't require a BMS. I think I want to replicate the 14s2p configuration with 18650s so I don't have to modify the original battery tray.

So I guess my main questions are:
Did you ever find a BMS that worked for this project?
What 18650s did you use? I think the V1 only needs 30a continuous discharge batteries.

Thanks for taking the time! Cheers