Charging multiple 3S batteries each has BMS ???

[Popebike]

Can i charge multiple 11.1 (12.6) volt 3S lithium batteries that have a BMS each at once using one charger and the batteries connected together in parallel?
Each battery has a different AH rating . One is 12AH made with new cells the others are between 8 and 10 AH and are made with used cells.
I want to charge 4 or 5 of this type of battery at once using one charger .i would be using a 140 watts of Solar power with a solar charge controller for lithium batteries or 2A charger made for 12.6 lithium 3S batteries.
Please let me know What you all think

 

[serious_sam]

If I was going to do it, I would put a diode in series with each pack.

 

[jonyjoe303]

It can be done with solar as long as you also put a lead acid in the mix. If all 3 lithium bms activate to stop the charge, the solar charge controller will still try to charge them resulting in voltage surges. The reason the controller will keep trying to charge them is because when the bms activates, the battery voltage will still read 11 volts (mosfet bms leak voltage) and the controller sees a battery connected that needs charging even if the bms won't let current pass. You will see voltage spikes as high as 20 volts, which will destroy anything connected to the battery.

If you have a lead acid also connected to the controller, it will continue charging and no voltage surges will be produce. The controller always needs some sort of usable battery connected when it's connected to solar panels.

 

[serious_sam]

i would be using a 140 watts of Solar power with a solar charge controller for lithium batteries

Do you have details on this charge controller ?

 

[Popebike]

From a seller on EBay

 

[john61ct]

scammer selling crap

 

[serious_sam]

I've got a similar solar controller for lead acid, and it works fine. Not mppt, but still keeps the battery charged. Lead acid are a lot more robust that lithium though, so poorly designed circuitry is less likely to cause major issues.

Not sure about the lithium version. I would test it on one pack to start with, whilst monitoring voltage and current with a multimeter. Make sure it operates as expected. Make sure it has a max current that you are happy with. Make sure it has a suitable max voltage (E.g. 12.6v for 3s). Check the behaviour when the solar panel goes from sun to shade and back again. Etc.

If it works as expected, then I would still run each pack with its own series diode. Go Schottky. You lose the top 0.5v of charge, but it stops current flowing between the packs if they are at different voltages to start with.
View attachment vs-20l15t-m3-1484189.pdf