Design Guide
How Many Ah Battery Do I Need in a Campervan?
Calculate the perfect battery capacity (Ah) for your campervan electrical system. This guide includes the formula, step-by-step calculation, lifestyle-based recommendations, and how solar panels affect your battery sizing needs.
Whether you're choosing between 100Ah, 200Ah, 300Ah, or 400Ah lithium batteries, use this calculator to size your leisure battery correctly based on your daily power consumption, appliances, and van life style.
The Simple Formula
Daily Power Consumption (Wh) ÷ 12V × 1.25 safety factor = Battery Capacity Needed
Example: If you use 1,000Wh per day
1,000 ÷ 12 × 1.25 = 104Ah battery
Step 1: Calculate Your Daily Usage
List all your appliances and estimate usage:
Total Daily Consumption: 1,700Wh
Step 2: Choose Your Battery Type
Lithium (LiFePO4) - Recommended
Use 100% depth of discharge (DOD)
1,700Wh ÷ 12V = 142Ah → Get 150Ah lithium
Lead-Acid - Budget Option
Use only 50% depth of discharge (safe limit)
1,700Wh ÷ 12V ÷ 0.5 = 283Ah → Get 300Ah lead-acid
Battery Capacity By Lifestyle
Weekend Warrior
Part-time camping, low power needs
Part-Time Van Lifer
Mix of city hookups and offgrid
Full-Time Offgrid
Constant independent living
Luxury Conversion
AC appliances, heating, multiple users
Don't Forget About Solar!
With solar panels, you can use a smaller battery because you're charging during the day:
100W Solar Panel
Generates ~0.5kWh on a sunny day = can reduce battery by 50Ah
200W Solar Panel
Generates ~1kWh on a sunny day = can reduce battery by 100Ah
Our Pre-Designed Kits
Don't want to calculate? We've done the math for you:
Essential Kit
Part-time / weekend trips
Premium Kit
Full-time van life
Ultimate Kit
Luxury / large families
Get Expert Sizing Help
Not sure what you need? We calculate the perfect system for your specific power requirements.