if you’re wondering what size of the battery bank to use or would like to work out the capacity of batteries (Ah) to use to attain a specific runtime for your appliances without affecting their lifespan then, read on this post is for you.
What Size of Battery Bank to Use?
There’s no one capacity (Ah) of batteries to use. The size that’s suitable for your application mainly depends on:
- the desired runtime for your appliances to run, and
- the voltage of the battery bank, whether 12V, 24V or 48V
What Size of Batteries to Power the Inverter for 1 hour?
This depends on if you’ve got a 12V, 24V, or 48V version of the inverter. For example, you’ll need 300 Ah of AGM or 150 Ah of LiFePO4 batteries at 48V to supply power to about 6000 watts of connected appliances continuously for 1 hour.
Note: This assumes that the batteries are not discharged below their recommended depth of discharge of 50% for AGM and 80% for LiFePO4 batteries.
At 24V, the battery capacity will be double, i.e. 600 Ah of AGM or 300 Ah of LiFePO4 batteries at 24V to supply power to about 6000 watts of connected appliances continuously for 1 hour.
battery capacity (Ah) = Power consumption of connected appliances (watts)/ (battery bank voltage x inverter efficiency)
Using the formula, 6000 watts / (48V x 85%) = battery capacity of 147Ah
What Appliances to Run?
Depending on the inverter design you may be able to wire it for either 120V or 240V. Check if your particular model of inverter supports this.
With the available 6,000 watts of power and up to an estimated 18,000 watts of surge power, equivalent to a 50 amp circuit at 120V, you may be able to run all the appliances in your home (depending on the overall power consumption and battery bank size) moreover simultaneously;
Note: Make sure you do not exceed the inverter’s continuous and surge power ratings!
This list is not exhaustive and only shows selected appliances that can be connected to the inverter.
- Washing machine
- Coffee pots
- Some AC units
How Long the Batteries Last
This pends on the power draw of connected appliances, the battery bank size, and the state of charge.
As a guide, a fully charged 300 Ah of AGM or 150 Ah of LiFePO4 batteries at 48V can run for about an hour before the batteries are discharged to 50% of their capacity (AGM) or 80% (LiFePO4).
There’s no one answer to how many batteries to use for a 6000-watt inverter.
The actual capacity (Ah) and the number of batteries to use depends on how much runtime you want your appliances to run for and of course the associated cost or budget available.