100Ah vs 200Ah LiFePO4: Which Size for a Camper?
A single 12V LiFePO4 battery comes most often as 100Ah or 200Ah. The honest way to compare them is usable watt-hours, not the headline amp-hour number. At 80% depth of discharge a 100Ah battery gives about 960 Wh usable and a 200Ah gives about 1,920 Wh — exactly double.
Biggest daily load each supports
| Days of autonomy | 100Ah | 200Ah |
|---|---|---|
| 1 day | 960 Wh/day | 1,920 Wh/day |
| 2 days | 480 Wh/day | 960 Wh/day |
| 3 days | 320 Wh/day | 640 Wh/day |
Read it like this: a 100Ah battery comfortably covers a 480 Wh/day build with two days of buffer — a fridge, fan, lights, and phones. Push past that with a laptop and Starlink and you are into 200Ah territory, or two 100Ah batteries in parallel. Cooking or air conditioning quickly needs 400Ah or more.
When to size up
- You run a laptop and Starlink daily for remote work.
- You want two or more cloudy days without recharging.
- You cook electric or run any 120V motor load regularly.
- You travel cold regions, where usable capacity drops about 20%.
Two 100Ah batteries in parallel equal one 200Ah bank and can be easier to fit and carry. Match your total to the daily load your build actually pulls — enter it below to see the exact amp-hours.
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.
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Battery bank
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Charge controller (MPPT)
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Inverter
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Battery-to-inverter wire & fuse
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Estimated cost
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Budget street price → premium brands.