Max inverter sizing

[thegoogler]

I have a self-built Lithium (LFP) battery in my camper with a JBD/Xiaoxang/overkill BMS that is rated at 120A continuous discharge (and fused as such). The LFP cells could handle 140A continuous/280A peak discharge, but the BMS cannot. What's the largest inverter I can safely run? My gut says 120A x 12V = 1440W, but I don't trust my gut.

(Separate question, do I need to do anything to pre-charge the caps in the inverter so the LFP battery doesn't blow them out or spark my battery terminal threads when I first connect it).

 

[Rednecktek]

I have a self-built Lithium (LFP) battery in my camper with a JBD/Xiaoxang/overkill BMS that is rated at 120A continuous discharge (and fused as such). The LFP cells could handle 140A continuous/280A peak discharge, but the BMS cannot. What's the largest inverter I can safely run? My gut says 120A x 12V = 1440W, but I don't trust my gut.

Nope, your math is right. You could probably go for a 1500w just because 1400w inverters don't exist but yes. If you can find a 1200w that would be about perfect.

(Separate question, do I need to do anything to pre-charge the caps in the inverter so the LFP battery doesn't blow them out or spark my battery terminal threads when I first connect it).

Would be a good idea although an inverter that small shouldn't pop your BMS's safety.

 

[thegoogler]

Awesome, thank you

 

[Oldwave]

victron 1200 va ve direct
I think that’s about 1000 watts or slightly more ?
progressive dynamics makes some models that are in the ball park. PD 1610 1000 watts
I think the 1800 watts would be a stretch. But might work.

 

[thegoogler]

victron 1200 va ve direct
I think that’s about 1000 watts or slightly more ?
progressive dynamics makes some models that are in the ball park. PD 1610 1000 watts
I think the 1800 watts would be a stretch. But might work.

In fairness about 1200w would be ideal. I'd really like to have the inverter shut down rather than blow my 120A battery fuse or my BMS rated at 120A continuous load because I ran too close to the limit. Peak draw is obviously a different beast.