Hmmm could be a good option. I like the charge only ones because of their cost, but I run discharge in my build because I trust it a little bit more to keep my battery safe
I’m glad you posted this, I have a pack built of salvage 30Q cells, a few P packs have drift. I tried the active balance on the BT bms, but as you said above, its just too slow.
I’m going to order one of these and wire it in up alongside my BT bms and see if it can prolong the life of this pack.
so… put this pack aside for a while, didn’t really think about it.
but, need to put it to use so took voltage readings today.
and…some interesting changes:
by some unknown mechanism the drift has nearly balanced out.
voltage across all cells have reduced, some more than others.
cells 5 and 6 have dropped by 0.02v, while cell 1 has dropped 0.12v.
this could also be caused by not letting the cells settle after charging on the previous reading…
not sure what’s happening here, but the balancer itself does draw a bit current so this can’t be plugged in and forgotten forever. i bet after a few months the current draw will be significant enough to drain the cells down to dangerous levels, especially if it’s not fully charged.
anyway, i was checking voltages by reading the pins here:
After installing the balancer leave it overnight and all the indicators lights are off meaning it’s done balancing. Check all the voltage to my surprise every cells 3.9v this thing really works!
I just want share it my finding and experience. Pardon my English second language
I have a question that is somewhat relevant to the topic. I have also received the same active balancer and plan to install it on the 10s4p I just built but I don’t want to add in a bms for charging. I have both evolve charges that I had planned to use. What charger have you guys been talking about that I can set cut off voltages to charge to? I’d love to just have this little guy and not the bms to.
I plan to use the balancer quarterly or Monthly just maintenance purpose only. You don’t need attached the balancer on battery all the time. What I did? leave the balancer connectors outside the heat shrink so, I can access easily next time want to use the balancer. I have custom charger 2amps stop at 40v from AliExpress.
A lab bench power supply? I read they are pretty easy to DIY with boost/buck converters… I’m trying to do this with solar…
I use a boost converter for adjustable voltage/amperage that I plan on connecting to a large battery bank charged by a 100W solar panel. Basically with enough energy from recycled batteries to charge my board + some, wired to a solar panel that will stay outside, maybe a display so I don’t have to probe when changing volts/amps, and some nice little dials instead of pots on the boost converter PCB in a 3D printed box.
Yeah thanks for sharing that info. Casually drops in sailing round the bahamas for 8 months while we are all slogging it out working in our various countries.
I’m living 8 months a year in snow and cold weather. Don’t need a solar panel to keep my beers cold. Hah yeah that’s right! Living the dream right here!!!
I bought the big version of these, with 2A balance current and bluetooth control/monitoring. I have some thoughts.
We’re normally top balancing (balancing cells when charging, when they are full).
I believe the balance function on these is always on, looking for deltas and kicking in the balancer. Balancing when the cells are not close to full is probably a waste of energy and cycle life. The effect might be negligible though. I’m thinking if you discharge down to cutoff, the cell voltages will probably have big differences, which we don’t care about unless one of the cells is below the healthy cutoff voltage.
Also, the balancing current is hardwired at 1A, until it reaches the voltage threshold, then stop, right? This is not cc/cv. Just cv. There’s a bunch of subtle behaviors here, but maybe no worse than the typical balancing via discharge. If you just do cv to 4.2v, when you remove charge voltage, the cell voltage will drop a bit. If you’re not doing the CC part of the charge the same way for every cell, SOC for each cell may differ. Etc.
The bluetooth one has a global on/off via app, but it’s a lot more money and relatively huge.
If the unit could be turned on or off on demand, to deal with passive drain and to only balance when you tell it to, perhaps every 10 charges, I think it might be good.
Also bring the balance pins out to a connector and connecting on demand seems workable.
BTW the bluetooth one discharges from the highest cell into a supercapacitor, then charges the lowest cell. You’d think 1A or 2A would be way way faster, but I since it can only do one thing on one cell at a time it may not be dramatically faster.
I was thinking a way to balance a 12s8p every 6 months or so…BMS only charge, so it will stop when the highest cell voltage of one cell it is higher than the other, therefore it will be unbalance in the near future, and will aggravate through time.
I you guys have a simple or better way to deal with this, please share.
I do not know if this is in the right topic. (hope so)
Yeah that’s the one I was talking about above. It’ll do what you want (balance the pack every 6 months or so). The app is nice, gives very good feedback as to what’s happening.
