Doctorbass
100 GW
Thundersky cell charged to 4.2V ... or 3.7V ??? THAT'S THE QUESTION
I am starting this debate here because i still have not found a decent explaination about that.
1: EV People know that the Thundersky cells have specs that suggest to charge them to 4.2V
2: We always known .. or learned.. that the recommanded LiFePO4 cells charge voltage is max 3.7V
3: The confusion reside about the fact that conventional Lithium cells ( LiCo,LiPo,LiMn) charge to 4.2V
The MAX CHARGING VOLTAGE OF THE TS CELL confusion reside about many infos:
-the fact that Thundersky may have forget to update their specs for LiFePO4 that is 3.7V instead of 4.2V max.. since ALL conventionals lithiums charge to 4.2V.. ONLY THE LiFePO4 CHARGE TO 3.7V
-The fact that some are saying that charging a TS cell to 3.7V will not fully give the rated capacity... ( only like 85%)
-We know that overcahrging a lithium cell above the recommanded voltage may make it become indtable and have some plating and damadge it.
Now here is the arguments:
-Some are assuming that charging the cell until it reach 4.2V and then STOP the charge(no CC-CV mode is used) is the same as charging it in CC-CV to 3.7V and then to cut when current reach C/20 ( conventional chrging method for Lithium) SEE THE ATTACHED GRAPH
But since charging LiFePO4 cell to 4.2V seems to damadge it... Why TS NEVER SPECIFY their SPECIAL voltage or advise people about that particular difference?
Why Ts would be so different than ALL the other LiFePO4 cells?? How can it be usefull to recommand to charge these cells to 4.2V?? I mean.. They are the only manufactur to have specs that suggest to cahrge to 4.2V instead of 3.7V like any others.
I know many persons would use the conventional BMS that top or shunt the charge to 3.7V per cell.. so why it is so complicated with TS ?
Why not just recommand to charge in CC-CV to 3.7V to everybody just like all other LiFePO4 Manufacture?
I still believe that keeping max current until 4.2V is certainly not helping for the cell life ! right ?
According to Battery university website, charging to 4.1V instead of 4.2V a conventional 4.2V lithium cell really prolong the cell life:
So I just imagine how it can be for a 3.7V to be charged to 4.2V !!!
Any great source for a perfect answer to that?
Any opinion?
Doc
I am starting this debate here because i still have not found a decent explaination about that.
1: EV People know that the Thundersky cells have specs that suggest to charge them to 4.2V
2: We always known .. or learned.. that the recommanded LiFePO4 cells charge voltage is max 3.7V
3: The confusion reside about the fact that conventional Lithium cells ( LiCo,LiPo,LiMn) charge to 4.2V
Recommanded Lithium cell Voltage Range, the sumarry :
LiCo: 3.0 to 4.2V
LiPo: 3.0 to 4.2V
LiMn: 3.0 to 4.2V
LiFePO4: 2.5 to 3.6... some say 3.7.. best is 3.65V
The MAX CHARGING VOLTAGE OF THE TS CELL confusion reside about many infos:
-the fact that Thundersky may have forget to update their specs for LiFePO4 that is 3.7V instead of 4.2V max.. since ALL conventionals lithiums charge to 4.2V.. ONLY THE LiFePO4 CHARGE TO 3.7V
-The fact that some are saying that charging a TS cell to 3.7V will not fully give the rated capacity... ( only like 85%)
-We know that overcahrging a lithium cell above the recommanded voltage may make it become indtable and have some plating and damadge it.
Now here is the arguments:
-Some are assuming that charging the cell until it reach 4.2V and then STOP the charge(no CC-CV mode is used) is the same as charging it in CC-CV to 3.7V and then to cut when current reach C/20 ( conventional chrging method for Lithium) SEE THE ATTACHED GRAPH
But since charging LiFePO4 cell to 4.2V seems to damadge it... Why TS NEVER SPECIFY their SPECIAL voltage or advise people about that particular difference?
Why Ts would be so different than ALL the other LiFePO4 cells?? How can it be usefull to recommand to charge these cells to 4.2V?? I mean.. They are the only manufactur to have specs that suggest to cahrge to 4.2V instead of 3.7V like any others.
I know many persons would use the conventional BMS that top or shunt the charge to 3.7V per cell.. so why it is so complicated with TS ?
Why not just recommand to charge in CC-CV to 3.7V to everybody just like all other LiFePO4 Manufacture?
I still believe that keeping max current until 4.2V is certainly not helping for the cell life ! right ?
According to Battery university website, charging to 4.1V instead of 4.2V a conventional 4.2V lithium cell really prolong the cell life:
So I just imagine how it can be for a 3.7V to be charged to 4.2V !!!
Most cells are charged to 4.20 volts with a tolerance of +/?0.05V/cell. Charging only to 4.10V reduced the capacity by 10% but provides a longer service life. Newer cell are capable of delivering a good cycle count with a charge to 4.20 volts per cell.
Any great source for a perfect answer to that?
Any opinion?
Doc