Sorry, I don’t know. There can be up to dozens of parameters being set for balancing-related stuff and different algorithms for balancing. I haven’t researched the specifics of how those BMS handle balancing.
The designers/manufacturers should hopefully have a document (or link) available with that information though.
This thread has been a great read, but seemed to end abruptly.
I’ve just attached the balance leads to my first Esk8 battery, a 10s2p of 15 amp 2600mah Dmegc cells, and a dumb Daly 20amp BMS wired for harge only, which specs a 4.18v balancing voltage and a max current of 30mA
All the cells were 3.600, +/- 0.001 on arrival, but I messed up some welds and when removing the strips, some sparks flew briefly, and 2 p groups were discharged to 3.570.
Tonight, I was hovering over it while charging up towards 42v, Dmm probes in hand, IR temp gun, watching the ammeter, and when it rose above 41.8v I was hoping to see something resembling balancing, start happening.
The 2 p groups, were still 30mv below the other 8 when 2 amps of charge current started tapering. Holding 42v steady, I watched amperage tapering down, and kept probing each p group. 8 were @ 4.20x, but the2 sparked P groups were @ 4.17x volts.
I was probing temps on batteries with ir gun, no difference anywhere. The BMS was not heating, and my clampmeter on balance wires, which cannot read below 60mA , read nothing. Amps tapered down to 0.08, and the nothing changed, 8 groups at 4.2, 2@ 4.17. and BMS was not warming at all.
When the cursing subsided, i Realized how little 30mA is. Bleeding off 30mA across the 8 4.20v cells. While the other 2 (hopefully) caught up?
No way was I going to leave it charging overnight at 42v unattended.
No way was I going to turn charging source up past 42v to perhaps speed the resistive bleed of the high 8.
I disconnected 42v charger entirely.
I rigged up a 4.2006v supply and clipped it to a 4.17v pGroup , and my clampmeter registered 250mA. About 30 minutes later it registered 60ma, and I put it on the other 4.17v pGroup and it too accepted 250mA. When that tapered to 60mA I removed it.
Plugged 42v source to battery, and it quickly tapered down to 100ma.
Disconnected it and 42v dropped to 41.92v.
Checked each Pgroup individually, 4.19v. Good enough.
What Did strike me was just how quickly pack voltage went from 4.18, to 4.20 at a 2 amp charge rate, and how quickly amps taPered down to 0.3 @42v.
Seems like very little time to do any balancing, especilly if the max balance current is 30mA, and that 30mA would likely only be realized if one cell was 4.21v+ and the other 9 were 4.18v.
I’m gonna cycle and monitor the 2 cell groups which got sparked briefly, before heatshrinking the pack, and am glad my learner battery is only a 10s2p of inexpensive cells.
My expectations of my BMS’ ability to balance a 30mV delta, in a timely manner, was unwise in the extreme.
30mA can be an effective level of balancing current but won’t accomplish anything quickly. Also working against you is that most BMS’ will alternate between balancing the odd and even numbered cells to prevent overheating of adjacent channels. This means that the balancing current is actually 15mA (averaged).
Some bms’ will continue to balance even after charging stops while others will stop when the charger stops, or even before that (when a certain charging current threshold is reached).
For any balancing though, regular use and charging of the pack ensures that a minimum of balancing is needed. Store the pack for a few months or short circuit some cells and balancing can take forever. 
I was not able to detect the BMS heating at all with an IR temp gun. Table top was 70f, BMS was 70f an hour after it passed 41.8v, cells were all 72f charging from 36 to 42v at 2 amps.
Wish I had a clampmeter which could read low currents.
I don’t think I can trust this BMS.
Or is it just that it was trying to bleed 8 groups at 30mA combined, and 3.75mA just is not going to warm uo the face of the BMS?
There was no indication it was , or is, doing anything.
With P- and B- connected, but the balance plug unplugged, there was no voltage on the charge port connector, but thats it.
Not sure I want to try testing OVD or LVD.
All cells read 4.19 now, after manually injecting 4.2v into the two 4.17v groups.
Each cell has its own bleed resistor so the balancing current will be 30mA, probably at a 50% duty cycle, for each cell.
You can read the voltage across the bleed resistors (or check their temp with the gun pressed up against them to narrow the gun’s field-of-view). If the voltage is zero then no current. If the voltage is almost the cell voltage then current is flowing.
This 10s 20 amp Daly BMS is potted, no getting at the guts to probe resistors.
I’ve was holding IR gun right against the casing and slowly searching.
No temperature increase at all with a 30mv difference on Pgroup 8 and 9, for an hour.
No change in VDelta either, but my DMM only registers two decimal places above 4v
Perhaps that is not enough Delta to trigger balancing?
Maybe I got a bogus Daly.
You’ll never get decent temp readings through potting IMO unless you get a bunch, or all, of the cells up to the balancing threshold so a decent amount of heat is being created.
You need to find all the settings/specs for that BMS so you can know how a genuine one will behave.
Specs say 4.18v and 30mA.
Wonder if I should bump charge voltage to 42.5v and see if I can detect a temp increase.
Wonder if i should just cut the thing out and pry it apart for science, then sledgehammer it repeatedly whilst cursing violently.
Sick of buying crap product with extra special marketing.
Forget temp increase measuring.
Unbalance the cells a bit, let them rest, then charge normally, let them rest, and see if they have balanced back at all. If not then discharge a bit and charge again. Then check for better balancing.
Basically, see if the BMS does what it’s supposed to do knowing it will do it slowly.
Ok, will do.
I just checked with DMM and all cells are 4.19, but 2, not the same cells as yesterday, will toggle between 4.18 and 4.19.
Just found another Daly pdf that says after confirming sequential voltage increase on balance connector and then plugging in balance connector to BMS, then hook Blue wire to battery -.
I had blue wire connected to battery - already, when I inserted balance connector.
crap.
I’ve never heard of a BMS saying to connect the balancing leads before connecting the main pack NEG but I’m pretty ignorant of what Daly’s need and the instructions should have the correct info…hopefully. Double-check that it’s for your particular model BMS though.
Thanks Mooch.
Imma gonna go take my dog a kayaking an a cormorant hunting, and try and clear my head, open Laptop tonight, and do a better search.
Daly’s website is phone throwing infuriatingly annoying, and I’ve not found any more details regarding my 20 amp common port bms.
The best info regarding the wiring of it, seems comes from sellers of it.
Here’s a screenshot of the one page pdf they link.
Note the charge voltage of 4.25*S.
IDFK.
I awoke Saturday to find all cells within 10mv of each other, 4.19v, but 2 groups would briefly show 4.18, then toggle back to 4.19.
I discharged the 10s pack , through the BMS, into my 7S esk8s through the step down converter at upto 3.5 amps, probing the balance tabs a dozen times, and once below 4v, my dmm reads 1mv resolution and the biggest delta I saw was 4mv under load, and it was not the groups which stained my undies sparking when peeling off inadequately welded strips.
Most readings under load, to my surprise and pleasure, were within 2mv.
I stopped discharging it about 3.580v and there was only 1 or 2 groups 1mv lower than the others.
I checked the resting baTtery severaL times, and all day today, and just now, there was no delta.
Every cell was exactly the same .
I thought my Dmm was busted, and changed out its batteries.
Same result.
Every group is 3.592v.
Makes me wonder if the thing is balancing, whenever there is no load or charging source applied, and the 4.18v detect and release spec is just BS written by marketers, not the engineers who designed it.
I am a ways from employing this battery in my esk8, so will leave it in perfect balance at 3.592v, and spend my screen time researching other things.
Easily tested. Unpot the thing and get all the answers you need.
Or just move on to those other things.
