Caravan Battery Size Calculator
Work out what size lithium (LiFePO4) battery your caravan needs, shown in both Wh and Ah at 12V, 24V and 48V, based on your daily use, days of autonomy, solar and charging.
Use the Caravan Power Calculator to build this figure from your actual appliances.
Recommended Battery Size
Recommended capacity
2.9 kWh
At 12V
242 Ah
At 24V
121 Ah
At 48V
60 Ah
Because you indicated you'll have solar, this estimate assumes it meaningfully offsets consumption on about half your travel days — you may need less if your solar array is large, or more if it's small or conditions are poor. Use the Solar vs Battery Balance Calculator to model this more precisely. Recommended capacity = (daily Wh × effective days) × (1 + 20% reserve), rounded to a clean figure. LiFePO4 (lithium) is assumed as the chemistry, since it's the standard choice for new caravan/RV battery banks and tolerates a much deeper discharge than lead-acid.
Why Ah figures change with voltage
Watt-hours are the true measure of energy — Ah only makes sense once you specify a voltage, since Wh = Ah × V. A 200Ah battery at 12V (2,400Wh) stores the same energy as a 100Ah battery at 24V (2,400Wh) — this is why 24V and 48V systems, common in larger caravans and off-grid cabins, use lower Ah ratings for the same real capacity.
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Frequently Asked Questions
What size battery do I need for my caravan?+
It depends on your daily energy use, how many days you want to go without recharging, and whether you have solar or regular charging. Enter your figures above, or build a detailed appliance list on the Caravan Power Calculator first.
Should I choose a 12V, 24V or 48V system?+
12V remains the most common choice for caravans and compatibility with 12V appliances and accessories. 24V and 48V systems are more common in larger installations (bigger inverters, cabins) where lower current for the same power reduces cable size and losses. This is a system design decision best made with a qualified installer for anything permanent.
Is lithium (LiFePO4) worth it over lead-acid for a caravan?+
LiFePO4 offers much deeper usable discharge, longer cycle life, lighter weight and faster charging than lead-acid, at a higher upfront cost. Most new caravan and RV battery installations now default to LiFePO4 for these reasons — see our LiFePO4 explainer guide for more detail.
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