Is there such a thing as a 14s balancing board that uses the same connector as a standard Daly BMS?

[Klauts]

Hello again everyone! I had a mishap with the new battery and ended up cracking the case real good nothing was damaged internally and it gave me an excuse to look inside the pack and see what the voltage was on each of my cell groups as well as to check the quality of the welds and that none were damaged when the case cracked.

I found that one group is .2v below the others it would appear, not extreme but I might as well fix it now that the battery has been opened.

I'm wondering if anyone has ever seen an Active balancing board that uses the same 14 wire connectors as a standard 14s Daly BMS?

I'm hoping to find a balancer that I can simply unplug the balance wires from the BMS and straight into the balancer...

Any recommendations would be greatly appreciated!

 

[eee291]

Very unlikely to find one. You could just put a daly plug on the balancer.
The proper way to do it would be to solder the new wires from the balancer directly to the cells, as the wires are usually thicker.

 

[amberwolf]

Is there such a thing as a 14s balancing board that uses the same connector as a standard Daly BMS?

You might look at Methods' threads about Daly BMS, as he was looking for something similar IIRC. I dont' recall what he found. I'm sure there was at least one other recent thread for the same thing, too.

I'm hoping to find a balancer that I can simply unplug the balance wires from the BMS and straight into the balancer...

While you could do this, the balancer won't be able to do what the BMS does and protect it from overcharge or overdischarge.

All it can do is whatever balancing function it was designed for, down or up to whatever cell voltage it was designed to do this at. (assuming it's not programmable; I don't know of any that are)

If it's only designed to drain high cells down (most typical balancing method) then it cannot fix any cells that are below that high point.

It also will likely have *at best* the same balancing time your BMS would, possibly take even longer.


I would suggest instead that you simply let the BMS do the balancing job it was designed to do. If the difference in cell voltages is great enough, it could take hours, to days, or more, of leaving the pack on the charger, to bring up the low cells and drain down the high ones, as it repeats the process of allowing charge, turnign charge off, draining high cells, etc.

If the time it takes is longer than you want to spend, then you can manually balance cells with a resistive load to drain high ones, and/or a single-cell charge source for the low ones. There are many threads that describe this process in various ways with various equipment.

I found that one group is .2v below the others it would appear, not extreme but I might as well fix it now that the battery has been opened.

This is actually extreme, and indicates a serious problem with the battery, especially if it is new.

It is either:
--built of mismatched cells that have different capabilities / capacities,
or
--one or more cells in one or more groups are defective or damaged,
or
-- the interconnects are damaged or improperly installed such that one or more of the cells in one or more groups is disconnected from the other cells.

A minor imbalance would be a couple of hundredths of a volt (like 0.02v).

A couple of tenths of a volt is a huge difference in state of charge (SoC).

A good BMS will not even allow you to charge or discharge a pack with this severe an imbalance because it could indicate a problem that could lead to a fire in some cases such as
--a damaged or defective cell with an internal short draining down the others in the group,
or
--enough disconnected cells in a group such that the discharge load on the remaining cells, or charge current thru them, will exceed their abilities by enough to cause unacceptable heating in them.

 

[lnanek]

I use a balancer that makes connecting to that port easy. It has a bunch of screw down terminals, one for each balance wire:
https://amzn.to/3GSZQoA


So I just wired in a bunch of these JST connectors and it plugs into the port my battery's BMS uses for balancing just fine:
https://amzn.to/3Hi10v7


A lot of BMS will refuse to balance it the cells are too different, so this saves having to use a 1S charger to individually fix some, or the discharging balance function on my cell meter which can overheat and only balances 7 p-groups at a time:
https://amzn.to/3Wr1gfV

 

[ZeroEm]

Yes, yes I like it.