Sparfuchs
1 kW
- Joined
- Nov 22, 2020
- Messages
- 305
Hello EV friends,
i'm about to build a 14s4p battery pack with samsung 21700 40t cells and a BMS that handles a charging current of 30A.
Now i'm having trouble to figure out what Charger works best with my battery and how to know and calculate for further projects with different specs. I want to charge my packs as fast as possible BUT still in the range for ideal cycle life (in case there is a correlation). The Datasheet of the cells says:
As i didn't even know what CCCV means i started my research there and quite understand that now but still don't know how the specs do tell me what charger to buy. According to the rated charge of 6A i could charge max. 24A (6Ax4p). But is that also reasonable for the cycle life ? And although i don't know what is meant by the 100mA /200mA cut-off, i guess it somehow describes the curves of the CCCV process ? But how do i know if for example a 20A charger reduces the current the way the cell needs it ? Do i think to complicated ?
If a charger says "58,8V/20A Lithium-ion Charger" how do i know if it's what i need ?
And btw... i really want to avoid buying a expensive adjustable charger so i'd rather go with a slower charger (but still, how low do i have to go to make sure its safe ?)
Sorry for my confusion and thanks a lot for your help.
Best regards Sparfuchs
i'm about to build a 14s4p battery pack with samsung 21700 40t cells and a BMS that handles a charging current of 30A.
Now i'm having trouble to figure out what Charger works best with my battery and how to know and calculate for further projects with different specs. I want to charge my packs as fast as possible BUT still in the range for ideal cycle life (in case there is a correlation). The Datasheet of the cells says:
Standard charge: CCCV, 2A, 4.20 V, 200mA cut-off
Rated charge: CCCV, 6A, 4.20 V, 100mA cut-off
This " Standard charge" means charging the cell CCCV with charge current 0.5C
(2,000mA), constant voltage 4.2V and 200mA cut-off in CV mode at 23℃ for capacity.
.Rated charge means charging the cell CCCV with charge current 6A and 100mA
cut-off at 23℃
As i didn't even know what CCCV means i started my research there and quite understand that now but still don't know how the specs do tell me what charger to buy. According to the rated charge of 6A i could charge max. 24A (6Ax4p). But is that also reasonable for the cycle life ? And although i don't know what is meant by the 100mA /200mA cut-off, i guess it somehow describes the curves of the CCCV process ? But how do i know if for example a 20A charger reduces the current the way the cell needs it ? Do i think to complicated ?
If a charger says "58,8V/20A Lithium-ion Charger" how do i know if it's what i need ?
And btw... i really want to avoid buying a expensive adjustable charger so i'd rather go with a slower charger (but still, how low do i have to go to make sure its safe ?)
Sorry for my confusion and thanks a lot for your help.
Best regards Sparfuchs