Inverter & Battery Calculator
Select appliances you want to run during load shedding, set your backup hours, and get an instant inverter & battery recommendation.
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Frequently Asked Questions
What size inverter do I need for load shedding in South Africa?
For essential loads (lights, fridge, router, TV), a 3 kVA inverter is the most common choice. Add a kettle or microwave and you need 5 kVA. For whole-home backup including geyser and AC, you need 8-10 kVA.
How many batteries do I need for my inverter?
Battery size depends on your load and backup hours. For a 3 kVA inverter running 400W for 4 hours on a 48V LiFePO4 battery: 400W × 4h ÷ (48V × 0.8) = 33 Ah, which means 2 × 100Ah batteries.
LiFePO4 or lead-acid battery for load shedding?
LiFePO4 (Lithium) is the clear recommendation for South African homes. It lasts 10-15 years with 4,000+ cycles, while lead-acid lasts only 2-4 years with 500 cycles. LiFePO4 can discharge to 80% while lead-acid should only discharge to 50%.
Can I run my fridge and freezer on the same inverter?
Yes, but you need to account for both their running wattage AND their start-up surge (which can be 3-7× the running watt for compressors). A 3 kVA inverter can typically run a fridge and a small freezer simultaneously.