The inverter size (5kVA) does not decide your battery. Your night use does. But here are the common setups.
First: the voltage
Most 5kVA inverters are 48V. Your battery bank must be 48V too.
Lithium setups (most common now)
| Lithium | Energy | Usable | Good for |
|---|---|---|---|
| 1 × 48V 100Ah | ~5kWh | ~4.5kWh | Lights, fans, TV, fridge all night |
| 2 × 48V 100Ah | ~10kWh | ~8.5kWh | Add an AC for most of the night |
| 1 × 48V 200Ah | ~10kWh | ~8.5kWh | Same as above, one unit |
Lead-acid setups (older style)
12V batteries must be joined four in series to make 48V.
| Lead-acid | Energy | Usable (~50%) |
|---|---|---|
| 4 × 12V 200Ah | ~9.6kWh | ~4.8kWh |
| 8 × 12V 200Ah | ~19.2kWh | ~9.6kWh |
Eight heavy batteries take a lot of space and die in about 2 years. One or two lithium units do the same job for many years. Read lithium vs tubular.
Quick guide
- No AC at night: 5kWh lithium
- AC for a few hours: 5kWh to 8kWh lithium
- AC most of the night: 8kWh to 10kWh lithium
