How To Quickly Charge 12V Lithium Battery Bank With Generator And Power 12V Loads At Same Time

Updated 01/13/2026 | Published 01/07/2026

Question:

I’m running a large lithium battery bank and short generator runs. Will the 100 amp PowerMax PM84VR actually work well here? or is a standard charger unit better? I was hoping to also run some 12v appliances while charging.

asked by: Rob

Expert Reply:

Hey Rob. Yes, that’s exactly the type of situation the PowerMax # PM84VR 100 amp converter is built for. When you’re charging a large lithium battery bank, the batteries can accept much higher current than traditional lead-acid batteries, especially when they’re at a lower state of charge.

With the # PM84VR, you can push significantly more charging current during short generator runs, which means less runtime and more usable power stored in the batteries. At the same time, the converter will still power your 12V loads directly while charging, so you’re not sacrificing comfort while you recharge.

As long as your battery bank is 12V total and your existing wiring is already sized for a 100-amp converter, the # PM84VR is a strong fit for that kind of use. How many amp-hours of lithium are you running?

expert reply by: Andrew N

Rob

1/13/2026

I’m running two 200Ah lithium batteries right now, so 400Ah total. Sounds like the 100 amp makes sense then.

Andrew N.

1/13/2026

@Rob Oh nice! Yes, with a 400Ah lithium bank, the # PM84VR is a really good match. That setup can actually take advantage of the higher output during generator runs, which is where the 100 amp converter really shines.