Charging above 4.2v a cell during start of charge

[Alex07]

I have an adjustable cc cv power supply, I noticed I can put in a lot more amps quickly if I set the charger to 4.3v a cell at the start of the charge till near the end.. and then neat 4.15 then I reduce down to 4.18 v a cell.

is this safe so as long as I stay under the max charge C crate and also stay under the final voltage of 4.18v a cell ?

i.e does charging with 4.3v a cell ( that is not full so its really under this ) damage the cell in any way as if it was full at 4.3v a cell ?

Because it allows me to charge a lot faster, is this what Teslas does at the start of a charge to speed up the process or do they charge increase the amps at the start ?

 

[999zip999]

Stop it at 4.1v then reset. Just dont go over 4.2v.

 

[Alex07]

Stop it at 4.1v then reset. Just dont go over 4.2v.[/quote

The tricky part is whilst you are charging its hard to know what the battery voltage is.. as on the charger its 43v.. so the only way to know is to stop the charge and measure and then go back. and recheck. but this is tricky and time consuming.

 

[Hillhater]

As etrike said, if you measure at the cell (at the pack direct) even whilst it is charging in the CC phase, the voltage will be well below 4.0v until the cell is 70-80% charged.

 

[dogman dan]

Safe till you forget, and let it charge above 4.2v. Set it to 4.28v perhaps? So you won't have too many cells above 4.3v if you forget.

Mo bettah, to just get a higher amps charger of course. But you can zap it hard ( but still under it's c rate limit for charge rate) for a quicker, opportunity charge that will never be long enough to fill it.

I've plugged well discharged 36v packs into 48v, for 15 min. Just because you see more than 42v with the charger on, does not mean the cell actually reached 58v.