charger voltage output max out

[splitfire]

i had a problem with my charger before. When i bought it new it was 87.6v which is right according to the label. After 3months of not using it, it drops to 86v output. I tried to open my 6amp charger. I saw 3 variable trimmers in the board. I tried playing 1 of the trimmer and it works. I got it raised back up to 87.6v but since i am using a lipo 21s which is 21x 4.2 = 88.2v . So i raised it up to 88.2v to use the maximum potential of lipo.

 

[dnmun]

what BMS will you use? i have 24S of lifepo4 balancing at 3.60V in parallel with my 21S of lipo and i charge to 87.6V.

so i overcharge the lifepo4 a little and accept a little undercharge of the lipo. 21S of 4.18V balancing voltage is 87.8V.

 

[splitfire]

You need a seperate bms for your lifepo4 and lipo, for charging you can charge it the same time just parallel them. The 87.6v output is actually for lifepo4. However you can also use that in lipo 21s it will be 4.17v per cell. Or increase your xharging voltage to 88v. Lifepo4 can handle up to 3.7v

 

[dnmun]

we have learned that it is best to balance the lifepo4 to 3.60V/cell to reduce plating out of lithium. i charge and discharge my lithium packs sin parallel. i do not charge them separately but each has their own set of two D131 BMSs. so 4 BMSs between 2 packs.