Steps To Calculate The Size Of The Battery Bank Needed For Your Home

Batteries used for homes usually have capacities ranging from 75Ah to over 300Ah.

Let's assume that the total power requirement was 467 Watts. Let’s also assume you want to run the system for 7 hours when there’s a power outage. Let’s calculate the number of batteries you’ll need in the next few steps:

Assume:

Back-up time: 7 hours

Days of autonomy: 1
Days of autonomy means the number of days a battery bank can provide the appliances you have connected to the system without being recharged.


Calculate the total energy of the battery bank

Total Energy of the battery bank = (Total Load (W) x Backup Hours) x Days of Autonomy;

Calculate the total energy of the battery bank

Total Energy of the battery bank = (Total Load (W) x Backup Hours) x Days of Autonomy;

Total number of batteries

Divide the total energy of the battery (Assuming you’re using a 200Ah battery for your design. It could 150AH) by the Battery Voltage x Capacity.

Approximately, that will be 2 batteries. Therefore, you will need two, 12V 200Ah batteries to power your load for 7 hours.