Answers · Sizing
How Many Batteries for a 5kW Inverter?
Direct answer
One 48V 100Ah (5.12kWh) battery runs a 5kW inverter at 1C for about 1 hour at full load. For 4-6 hours of backup, use 2-3 packs in parallel (10-15kWh). Rule: usable capacity (kWh) = load (kW) × hours ÷ 0.9 DoD.
The 1C rule
Most wall-mounted and rack LiFePO4 packs support 1C continuous discharge. A 5.12kWh pack = 5kW max. So a single pack matches a 5kW inverter's ceiling but drains in 1 hour. That is fine for short outages, not for all-night backup.
Parallel math
| Backup need | Packs (48V 100Ah) | Total |
|---|---|---|
| 1 hr @ 5kW | 1 | 5.12 kWh |
| 4 hr @ 5kW | 3 | 15.4 kWh |
| 6 hr @ 10kW | 6 | 30.7 kWh |
Luchu Energy 48V 100Ah racks parallel up to 16 units on a single busbar. FOB is $620-780 each . see the 2026 price guide.
Frequently asked questions
How many 48V 100Ah batteries for a 5kW inverter?
One 48V 100Ah (5.12kWh) battery supports a 5kW inverter at 1C discharge, but only for about 1 hour at full load. For 4-6 hours of backup, run 2-3 packs in parallel (10-15kWh). A 5kW inverter's continuous draw is 5kW, so size usable capacity = load × hours ÷ 0.9 DoD.
Need a parallel-ready system?
Luchu Energy racks parallel up to 16 units. Get a sizing quote →