How to Choose the Right Inverter Battery Capacity (Ah) for Your Home
Truenergy Team 1 min read
A simple 3-step method to work out how many Ah you need, with examples for 2BHK and 3BHK homes.
Battery capacity is measured in ampere-hours (Ah). More Ah means more backup. Here is a simple way to choose.
Step 1: Add up your load
List what you want to run during a power cut. Example: 4 fans (75W each), 6 LED lights (10W each), 1 TV (100W) and Wi-Fi (15W) comes to 475W.
Step 2: Decide the backup hours
How long are your usual power cuts? Say 3 hours.
Step 3: Calculate
Battery Ah ≈ (Load in watts × Hours) ÷ (Battery voltage × 0.8 efficiency). For 475W × 3h ÷ (12 × 0.8) ≈ 148Ah, so a 150Ah battery fits.
Quick guide
Our backup calculator does this math for you.
