Nominal Battery Capacity (C20) for Batteries in Parallel

[Disturbedfuel15]

Hello,

For the SMA Sunny Island SI-6048us, the manual reads:
"The battery capacity (parameter "221.02 BatCpyNom") is to be entered as the nominal capacity for a 20 hour discharge (C20)."

I have built a 16s5p 280ah 48v battery bank. These consist of four salvaged 20s 60v CATL modules, which I removed 4s from each, giving me (5) 16s 48v batteries. These do not come with a C20 discharge rate, nor any support, nor any documentation. They are what they are. The BMSes are JK PB2a16s20p.

1. I am starting to feel like C20 is what every battery 'advertises'. I.E. if it is a 280ah battery, that is its 'C20'. Is this correct for the most part?
2. I assume this is simple math and I would enter in '1400' as the 'BatCpyNom' (5 * 280ah). Is that correct?


Thank you in advance. I did try searching for quite some time but couldn't find an exact answer. Maybe my searching sucks, apologies!

 

[sunshine_eggo]

1. C20 is a lead-acid term as lead acid capacity changes substantially with load. LFP is typically rated at 0.5C or 1.0C, so just use 280Ah if that's the rating value you have.

2. Yep.