14s BMS suggestion please?

[amberwolf]

Before choosing a new one, knowing what specifically failed with this one would help find one that won't do that again.

What is the problem the battery pack is having, and under what conditions did it occur?

Hello,
My first post and just learned about this forum and great to be aboard.
A question please to those that have replaced their BMS on a Hailong shark style battery...in this instance the case is similar....shark style battery case is made by Reention.
Battery cell spec: 21700 Panasonic Tesla cells

14s x 4p = 52v 19.2 amp-hr.
Current BMS is rated at 45 amps

Please note, this BMS has an On/Off switch which wires directly into the battery On/Off rocker switch

I really don't want to do a smart BMS...maybe constrained by limited package size...tight packaging between cells and case bottom plate.

A picture of the failed BMS:
BMS slightly farther away.jpg

Motor application is Bafang BBSHD with stock controller for now and would like to stay in the 45-50a BMS size range for adequate headroom over the max draw of 30 amps the stock BBSHD is currently programmed for.

Any suggestions where to buy...or a link of a 'reliable' BMS??...which seems like a black hole to a newb like me that hasn't built batteries. If someone has a track record of success with a given supplier or brand/model BMS, this would be a great help.

Thanks very much.

 

[Diggs]

I gotten most of my BMSs from Aliexpress. Huge selection, great prices and they actually ship pretty fast.
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20220712041104&SearchText=battery+14s+bms&spm=a2g0o.productlist.1000002.0

But some don't like shopping on Aliexpress and Amazon has a pretty good selection also.
https://www.amazon.com/s?k=14s+battery+bms&crid=2KLARKUD0A4F1&sprefix=14s+battery+bms%2Caps%2C120&ref=nb_sb_noss_2

I like Daly BMSs personally.
https://www.amazon.com/Li-ion-Battery-Protection-Balance-Lithium/dp/B0B2RVXFP1/ref=sr_1_10?crid=2KLARKUD0A4F1&keywords=14s+battery+bms&qid=1657628216&sprefix=14s+battery+bms%2Caps%2C120&sr=8-10

 

[eMark]

Need to first determine if all 14 BMS balance leads are still intact (ok) for measuring p-group voltages ... AND ... determine current voltage of each parallel group.

First things First ... disconnect 14s connector from BMS. Then use DMM probes to measure voltages of each parallel group via 14s connector. Post the voltages of all 14 parallel groups.


PS: A 60A Daly only costs $3-$4 more than a 50A Daly. A JBD Smart BMS from Aliexpress may still fit in available space.

 

[eMark]

Every DIY battery should have such easy access without having to remove shrink wrap to troubleshoot suspect BMS ...

Makes so much sense you gotta wonder why every DIY build (w/BMS) doesn't do same? Very accommandating with BMS and/or battery problem, easy to check p-group voltage variances, easy to remove and replace if suspect a faulty BMS.

Another advantage is making it easy to disconnect BMS from battery when storing at nominal voltage (winter storage).

I really don't want to do a smart BMS...maybe constrained by limited package size...tight packaging between cells and case bottom plate.

Someone should design/manufacture weather resistance enclosure just for BMS. Including wires and balance leads in tuff flexible water resistant tubing with BMS connection and Battery connection also weather resistant for DIY builds.