Small RV With 12V Loads And Battery - Is Battery Charger Fine, Or Is Converter Charger Necessary?

Published 01/07/2026

Question:

I’ve got a small RV with basic 12V stuff and a battery charger already. What would the 45 amp PowerMax PM34VR add to my setup? Do I even need it?

asked by: Kevin

Expert Reply:

Kevin, that’s a good question. The PowerMax # PM34VR 45 amp isn’t just a battery charger - it also acts as a dedicated 12V power supply when you’re plugged into shore power. That means your lights, fans, and other small 12V accessories can run directly from the converter instead of always pulling through the battery.

Compared to using only a battery charger, the # PM34VR reduces how much your battery cycles when you’re plugged in, which can help extend battery life. It also gives you steadier 12V output under load, especially if multiple accessories are running at once.

If your RV has modest power needs and a separate DC fuse panel, the coverter is a simple way to make the system behave more like a traditional RV setup.

If you have a few low power things like a couple 12v led lights and a single 12v fan, you may get by with just using the charger instead of the converter charger setup. and wire the loads straight from the battery (with fuses of course). What kind of batteries are you running right now?

expert reply by: Andrew N