Top Balancing

[pkrboo]

After getting my new cells from ALiexpress, 105ah grade A new, I put them altogether and built my 12volts battery with DYKB low temp BMS that Will recommends. allgood and they charged up to full capacity acocrding to the BMS app. but they only charged to about 3.3 volts each cell

I have since seen the top balance video so took it all apart and putthem in parallel and am now charging at CV 3.6 volts and they are pulling about 5.2 amps. they have been like this for 6 hours, is that normal? they were at 80% SOC according to the BMS before I pulled it apart and reconfigured them into parallel.

how long will they take to get to 3.6 volts?

 

[MisterSandals]

how long will they take to get to 3.6 volts?

105AH x 4 = 420AH
420AH / 5.2A charging = 80.7 hours (full charge cycle)

 

[pkrboo]

105AH x 4 = 420AH
420AH / 5.2A charging = 80.7 hours (full charge cycle)

ahhhhhh, yes hadnt done the sums to make 420ah.

a small tweak has managed to get the PSU to push 9.2 amps now.

so it will still be a good 15 hours + to get from 80% SOC to 100%

 

[Uzi Tenenbaum]

If that's the case then I'm really confused.

All the videos you seem him put together 4 cells labelled at (described as) 3.2v 100Ah, then he measures the capacity of the entire battery pack and always gets around 100Ah. I just assumed they rated capacity as a 12v pack, am I wrong?

 

[Uzi Tenenbaum]

Nevermind, figured it out I think. Voltage difference accounts for difference in Ah in a series vs parallel setup. Hopefully that's right, sorry for the sidetrack.

 

[Denis]

105AH x 4 = 420AH
420AH / 5.2A charging = 80.7 hours (full charge cycle)

105amp at 3.2v x 4 = 105amps at 12.8v in serries or or like you said in parallel at 3.2v =420ah. Just to clarify

 

[Ampster]

but they only charged to about 3.3 volts each cell

Is that the charge setting or the resting voltage?