Options: 14S BMS with some form of balancing

[drebikes]

Hi all, what options would you recommend for a 14S BMS? It just needs to have some form of balancing. Not sure if it is realistic to aim for active balancing, thoughts?

 

[harrisonpatm]

JKBMS

 

[dominik h]

ANT
JBD
DALI

You have to give a little more Information.
Like max current and battery capacity.

 

[drebikes]

Thanks for the suggestions.

I want to make a very lightweight ebike pack: 14S1P Molicel 45B. Max current would be some 20A, continuous discharge around 5A

Some for of Bluetooth / app for data logging would be appreciated

 

[docw009]

I want to make a very lightweight ebike pack: 14S1P Molicel 45B. Max current would be some 20A, continuous discharge around 5A

Some for of Bluetooth / app for data logging would be appreciated

I recently used Molicell P42's to make a pair of lightweight 13S-1P batteries, A 14S would have been a better idea, but I had some inexpensive 13S BMS with balance laying around, I also have a 25A bluetooth JBD BMS, but it was too wide for this small pack and I didn't want to waste it on these batteries. I made them for use as spares, or in parallel.

Mine were 4.2AH cells, so that's about 200 WH. In actual ebiking, I'd see 140-150WH of effective use. Voltage sag at full charge with 25A was 6 volts. At 4A, it was 3/4 volt, Not all of that was in the battery. A lot is in my bikes' wiring, I tested on a 25A BBS02 bike and an 11A TSDZ2 bike, Range was 18 miles and 24 miles respectively, Happy with the results.

I am guessing you will see around 160WH.

 

[dominik h]

Jbd Mini smart bms 7-14S

 

[dominik h]

Link

 

[brone]

Link

It has passive balancing with low current, so not that great

 

[docw009]

Link

I bought a pair of those small JBD BMS units earlier this year. Still have to try them out, I am used to passive top balance BMS with 20-50 ma balance current.

 

[dominik h]

I have installed two of them , one in a A123 8S 20Ah Lifepo pouch pack and the other in a 10S4P E-Bike battery. They are small and lightweight and they do their job.
There are always bigger and beefier options.

They have an error log and Bluetooth. You won't find a cheaper and smaller one with all that features at the moment.

 

[drebikes]

Thanks for the amazing suggestions. I moved house 10 days ago and I have just gotten around to the hobbies. Passive BMS is not my forst option, but look, if I have to leave the pack overnight or over the weekend to balance (however slowly) no big issue, as long as it gets there.

In order to have the JBD BMS shipped to Spain, would you go for the Aliexpress supplier or is there someone in europe stocking them?

This link is stil Live https://www.aliexpress.com/item/1005004892183305.html

 

[chuyskywalker]

Passive is enough. If you are using molicel's, you likely won't every even need passive balancing, let alone active. And if the pack gets to the point where you regularly need significant time to rebalance, that's a sign that the cells need replacing, not more balancing amps.