how long should a 2,560wh last?

[JimJimmy]

at 100 watts an hour, how long before 2,560 watts is gone? 25 hours?
the battery is a 200amp 2,560wh LiFePO4 Battery.
I have a battery that is not giving me the length of time from the battery as I think it should.
I use approximately 100 watts, with a DC fridge, a few led's, and parasite rv stuff.
so how long should this battery last?

 

[rmaddy]

A 12V 200Ah battery is 2560Wh. That is correct. A 100W load will last 2560Wh / 100W = 25.6 hours. That is correct. But that assumes it's a steady 100W load and you use a full 100% of your battery's capacity.

How long is the battery lasting? What is the start and end SOC (state of charge)?

 

[feo]

there is a lot more detail needed to answer your question. But what you are asking is about charge/discharge efficiency.

What are your devices? (Model# for charger, battery, cabling, fridge)

What kind of measurement devices do you have? (Clamp meter, Multimeter, shunt, battery display, etc)

We can go from there…

 

[JimJimmy]

you are asking for specifics, I am just asking generalities, I have a shunt and it measures approximately 100watts with everything I use is turned on.