PowerMax AC to DC Converter for 150 Ah Lithium Battery

Updated 05/08/2026 | Published 05/04/2026

Question:

I recently replaced my propane refrigerator in my small trailer with an electric powered one. 20 years old, it died. As a result I am replacing my old 10 Ah AGM battery with a 150 Ah Lithium battery. I tend to camp in places that have a lot of tree cover, so solar recharging isnt viable. I carry a 1000 watt peak, 900 watt nominal generator to top off the battery when necessary. Typical load is 50-60 Ah per day. 75 Ah on a hot day. Is this PM94VR a good choice for replacing my existing charger since it isnt designed for lithium batteries? Most of the use would be to top off the battery when traveling, but also to keep the battery charged when parked over the winter. I would like to minimize generator use, so want to recharge as fast as reasonably possible given the size of the generator.

asked by: Henry M

Expert Reply:

Hey Henry! Yes, the PowerMax AC to DC Converter # PM94VR is a great choice for your setup. The 55A output pairs well with your 900W generator, so you’ll get fast charging without overloading it. This will give you lithium compatibility with efficient charging to keep your batteries topped off.

PowerMax calls for a minimum of 8 AWG wire, but for best performance I’d go with 6 AWG for shorter runs or 4 AWG for longer runs to reduce voltage drop. That will keep your 150 Ah battery charging as quickly and efficiently as possible.

What kind of trailer do you have?

expert reply by: Robin H

PowerMax AC to DC Converter
(click to enlarge)

Henry M.

5/7/2026

Robin Thanks for this. I have a Chalet. In reading about lithium battery chargers, many have a pre charge stage to wake a low voltage battery. While I hope that I never let my battery get that low, does this charger have the ability to wake a low voltage battery if that happens? Thanks Henry

Robin H.

5/8/2026

@HenryM the # PM94VR doesn’t have a true “wake up” mode for a fully shut down lithium battery, so if the BMS cuts it off it may not recognize it right away. If that happens, you would need a quick external charge (like a basic 12V charger or even a jumper from another battery) to bring the voltage up and then it will charge normally.