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.
2 year Follow up, and a bump.
My DMEGC10s2p battery( first Esk8 battery build) still works, but I found the battery well out of balance after resting at storage voltage for about 8 months.
It had one charge and partial discharge cycle in between for a test as a range extender parallel through charge port pack and then went back to storage voltage and was ignored for a few more months.
I was recently using this as a top mount range extender pack, its XT90s into a parallel ESC feed, and it was not getting too hot in this shared duty.
Pulling it out, I pulled balance connector and hooked up my dual 7S capable ‘capacity controllers’, 6 cells on one unit and 4 on the other.
100mv delta at storage voltage, and delta was the same at near full charge, and 500mV out at ~32 volts.
Twice, I charged it to near 41.6v when I choked max current to 0.22 amps then bumped up target voltage to 41.8v, and then, when amps read 0.00 on my inline wattmeter, bumped up voltage by 0.03v, in 5 or more stages, and some of those stages lasted overnight.
When i’d wake up to piss i’D turn it up 0.03 more voltage and amps would increase back to 0.14 again, and be at 0.00 next time I looked.
The order of the groups from lowest to highest never changed, and the Delta was almost exactly the same after these ‘balancing charges’
Still 100mv delta. Both times. Slow 1 amp charges to 41.6 v, then 0.22 amps to 41.8v, then bumped voltage up in no less than 5 stages to 42. This should allow 30ma bleed resistors to at least do SOME balancing.
It did twice disconnect the charging source when cell 10 hit 4.25 volts( group 7 was 4.149, both times)
I have since manually injected groups 7, 1, and 2 with a 4.2v supply set to get them closer to the other 7 groups.
This battery owes me nothing. The DMEGC 26E cells were a poor choice in Nov 2023. but I figured I’d screw up the first build and did not want to waste good cells.
It likely has 3K miles on it and I pushed it well beyond the DMEGC cell’s 60C limits many times before retiring it.
It appears as if this specific Dumb Daly BMS does not now have and never had, the ability to balance.
I have built 3 more 10S batteries using the same BMS, but I used half of an XT 30 on the Blue B- wire so I could plug in the Balance plug, and then the blue wire, like the directions state.
One of those 3 subsequent batteries was unintentionally submerged and ruined, but the other 2 are in use, on BAk45D and Eve 40PL cells.
I checked the balance on the BAK 45D 10s2p once, disconnecting Blue wire xt30 first, then balance connector, It was less than 20mv out of balance, Then hooking up balance plug then blue B- wire, as the Daly directions state( 2 posts up)
I was also rarely charging to above 41.8v where the Dumb Daly says balancing starts.
But that BAK balance check was months ago, and these cells might just naturally have been balanced to that degree then. I have not bothered checking since. Battery is working great. If I charge it to 41.80v and 0.00 amps at night then disconnect charging source, in the morning it reads 41.78v.
I have not checked the EVE 40PL 10s1p pack yet, as it has less than 200 miles on it.
I hope the subsequent dumb Daly BMS I employed, do have the ability to balance.
I will check the BAK45D’s 10s2P BMS for this ability in the future.
The Daly BMS I used in the 10s1P Eve 40PL had a temp sensor, and the balance plug was shifted to the side a bit compared to the previous versions.
I have a new one sitting on my desk now for the next 10s2P build, that says 20 amp charge and discharge.
Tenpower 50XG’s.
buwahahahhaaa.
I still have the BMS which spent 20 minutes submerged in the bay while smoky bubbles emerged from enclosure and my Supraspinitus was torn in 2.
Wonder if I should chisel it open for science?
The BMS, not my shoulder.
The submerged Daly BMS next to my newest one.
Their attempt at waterproofing needs some work.
Looks like it seeped inside around the P- and B- wires, and around the balance connector pins.
it also got down around the sides of the red heatsink and onto the thermal pads.
Granted this was submerged about 2 feet under water for 10 minutes or so, before I was able to lasso the front truck ‘s floating pneumatics and pull it out.
I can take better pictures if requested.
If it means anything that last image shows that the BMS has the ability to balance using two 100Ω resistors which is about 21mA at 4.2V ONLY if the balancing current is at 100% duty cycle. If an adjacent channel needs balancing the BMS will typically alternate between the two channels to prevent overheating and that = 50% duty cycle.
That averages out to about 10mA balancing current.
10mA should have been able to have changed the imbalance on my Dmegc pack, considering I had it connected for well over 24 hours above 4.18v and under 4.25v, but it didn’t.
So either this specific BMS’s ability to balance properly was faulty from factory, or my hooking up the B- wire, then the balance connector, in the opposite order as listed in the instructions, somehow neutered its ability to balance..
I do not have tools which can measure 10mA of current, so i have to observe whether imbalance changes when balancing conditions are met and held for long enough to have an effect.
I will do this on my BAK45D 10s2p in the future and report back. Thus pack employs the same BMS, purchased nearly a year later, and I believe i have followed the’ proper ‘ order in hooking B- wire, then balance connector.
.Maybe this order was important on older models and no longer is on the newer ones.
I wonser if there are lots of dumb bms’ out there that are not balancing.
I bet very few bother to check.
