RAM ProMaster Solar Calculator
The ProMaster's wide, boxy roof is a solar dream: panels lie flat and the extra width means fewer awkward gaps. Its front-wheel drive and square walls make it a favorite for DIY full-timers. Plan generous solar and a 300–400 Ah LiFePO4 bank if you cook electric or run air conditioning on the road.
Roof space: The widest roof of the class — 65–95 sq ft, friendly to 500–800 W.
A representative RAM ProMaster build
Based on the preset loads below (1,965 Wh/day at 4.5 peak sun hours).
- Daily energy
- 1,965 Wh
- Solar array
- 583 W
- Battery (LiFePO4)
- 410 Ah
- MPPT
- 80 A
- Wire & fuse
- 2 AWG · 175 A
- Est. cost
- $2,003–$5,843
Adjust the preset below for your exact appliances, location, and cold-weather needs. The calculator recomputes everything live.
Quick start with a profile:
Your daily loads
Add each device with its watts and hours per day.
No loads yet. Add your fridge to start, or pick a profile above.
Solar array
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Add loads to size your array.
Show the math
Battery bank
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Show the math
Charge controller (MPPT)
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Show the math
Inverter
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Show the math
Battery-to-inverter wire & fuse
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Show the math
Estimated cost
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Budget street price → premium brands.
Itemized breakdown
Embed
Next steps for your RAM ProMaster
- Compare battery chemistry in the LiFePO4 vs AGM guide.
- Check your region's sun with the location pages.
- Get the wire right with wire gauge sizing.
- Work through the full pre-purchase checklist.