Inverter Battery Backup Sizing Calculator
Determine required battery capacity in Ampere-hours (Ah) or calculate estimated backup time. Adjust running watts, target hours, and system voltages (12V / 24V / 48V) to match standard Indian battery capacities.
Guide to Inverter Battery Types in India
An inverter is simply a gateway converter; it is the **battery bank** that stores electrical charge and determines how many hours of power backup your house receives. Buying the incorrect battery structure leads to premature degradation and safety risks.
Tall Tubular Batteries
The gold standard for Indian home backups. Highly resilient, performs well during deep discharge cycles, and has a typical lifespan of 4-6 years. Requires regular distilled water top-ups.
Flat Plate Batteries
More compact and budget-friendly than tubular options. Charges faster, but has a shorter service life of 2-3 years. Ideal for regions with short, frequent outages.
Lithium (LiFePO4)
The modern premium standard. Zero maintenance, extremely fast charging, and yields up to 10 years of lifespan. Requires a lithium-compatible smart charger inverter.
distilled Water Maintenance
Lead-acid tubular batteries experience thermal electrolyte evaporation during charge-discharge cycles. Distilled water must be top-filled up to marked indicators every 3-6 months. Failing to top up exposes lead plates to air, causing irreversible sulfation damage that kills battery capacities.
Battery AH Sizing Quick Tips
What does Ah mean?
Ah stands for Ampere-hour. It measures electrical charge capacity. A 150Ah battery can deliver 15 Amperes of current for 10 hours at 12V under ideal conditions.
Depth of Discharge (DoD)
Tubular batteries should never be drained to 0%. Draining below 20% capacity causes chemical decay. Standard sizing calculations factor in an 80% maximum usable capacity limit.
Sizing Checklist
- Choose tubular for durability
- Avoid mixing old and new cells
- Keep terminals greased/clean
Battery Sizing FAQs
Q.How do you calculate battery backup time?
Backup Time (Hours) = (Battery Capacity in Ah × Battery Voltage in Volts × Battery Efficiency × Depth of Discharge) / Total Running Load in Watts. Typical efficiencies are 85% for inverter circuits and 80% Depth of Discharge (DoD) for tubular batteries.
Q.What battery size (Ah) is recommended for 4 hours of backup?
For a typical running load of 400W (e.g., 3 fans, 4 LED bulbs, 1 TV, and a router) on a single 12V battery, you need a capacity of around 150Ah to 180Ah to achieve 4 hours of backup comfortably.