Charging amps for batteries in parallel?

[jtzako]

I currently have 2x 48v LiFePO batteries w/ 103Ah capacity in parallel. The spec sheet recommends a charge amperage of 45A for a single battery. How do I determine the correct charging amps for the two batteries in parallel? I also plan to add a 3rd battery soon, so I want to make sure I am letting them charge properly.

 

[Ampster]

Amps add for things in parallel. So if 45 Amps is max for one then two could charge at 90 Amps and three at 135 Amps. You can charge at less Amps but it will take longer.

 

[BentleyJ]

I believe you mean 103 Amp hour capacity? 45A for a single battery sounds a little high, 0.2C to 0.3C is generally agreed as good charging current for longer battery life. That would be 20 to 30A for each battery in parallel. As Ampster has stated above, amps are additive for batteries in parallel.

 

[jtzako]

I believe you mean 103 Amp hour capacity? 45A for a single battery sounds a little high, 0.2C to 0.3C is generally agreed as good charging current for longer battery life. That would be 20 to 30A for each battery in parallel. As Ampster has stated above, amps are additive for batteries in parallel.

These are LiFePO, not Lead Acid, the .2 or .3C is for Lead Acid. Everything I've read suggests .5C for LiFePO. The Mfg is slightly conservative on that #, suggesting about .44C.