Converting Enclosed Trailer Into Mobile Workshop With 12V Battery, Converter, Lights, USB Ports
Published 01/07/2026
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Question:
I’m converting a work trailer into a mobile workshop and want 12V lighting and USB outlets whenever it’s plugged into a standard outlet. Do I need a battery for that?
asked by: Paul
Expert Reply:
Paul, you don’t have to run a battery for that setup. A standalone PowerMax converter like the 45 amp unit # PM34VR can power your 12V lights and USB outlets directly when plugged into shore power by converting AC to DC.
That said, adding a battery like # 34276285 can help stabilize the system and gives you short-term 12V power if the cord gets unplugged or you don't have shore/generator power for a shore while.
Either way, you’ll want a DC fuse panel / fuse box (something simple like # 3375601006) between the converter and your 12V circuits for safety. In some small cases, people just power the 12v accessories right off the battery bank with an inline fuse which can usually be just fine, and they just use a standard charger instead of a converter/charger, but the converter with a fuse box is the more proper and heavier duty way to do it.
Are you planning to ever use the trailer without being plugged in?
Product Page this Question was Asked From
PowerMax AC to DC Converter w/ Built-In 3-2-1 Stage Battery Charger - 12V - 45 Amps
- RV Power Converter
- Converter Only
- No Battery Mode Switch
- 12V
- 45 Amps
- AGM
- Gel
- Lead Acid
- Lithium
- Multi-Stage Charge
- PowerMax
more information >
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