Battery charge and discharge information

[vallesj]

I am just curious, the PWM I installed for my solar tracker controller on my 25w panel and 12V/6ah LFP

, gave me a graph similar to this... And I thought maybe it does not report accurately, but now with the growatt charts, a similar graph is shown.

I know charging a battery is not 100% efficient, but looking at the graph it looks like you need 2 times or more charging capacity for what you are discharging. May be this chart shows what is produced by the panels, and not what is used for charging.

I know some of you have an answer for my curiosity and may have a better way to view the real charge/discharge information.

 

[sunshine_eggo]

It's not that bad. "Ah" round trip on LFP is very close to 100% efficient, but when you account for the voltage sag under a load and the voltage rise under a charge, the Wh discrepancy is notable, but nowhere near 2X.

I suspect you're being fed garbage data.

 

[sunshine_eggo]

View attachment 222329

The above is either garbage data, or I suspect charging may include PV that directly powered loads.