ExpertPower 12V 200Ah (runtime analysis) Lithium LiFePO4 battery real world test
Product being tested:

ExpertPower 12V 200Ah Lithium LiFePO4 Deep Cycle Rechargeable Battery Description: 2500-7000 Life Cycles & 10-Year Lifetime | Built-in BMS
Results:
11:27 AM 2/28/2021
Start ~370 watt load
3:19 PM 2/28/2021
12.55V
3:41 PM 2/28/2021
12.43V
4:19 PM 2/28/2021
END
~1.845V (voltage below inverter low voltage disconnect, apparently due to BMS disconnecting load at “empty”)
Results: 4 hours 52 minutes runtime at ~370 watt inverter output
= ~1801Wh output (not accounting for inverter inefficiency)
Using inexpensive Bestek 500W 12V to 110V AC inverter (actually around 116V AC) to power constant 370 watt resistive load.

Other misc. notes/calculations.
2560Wh rated
1850Wh used…
~2035W actually used?
79% at 90% efficiency
If inverter efficiency ~90%
Or ~2127.5W at 85% efficiency
83% of rated capacity…
- expert power lifepo4 battery review (1)