How long will a 3 kVA UPS with two 200 Ah tubular batteries last?
From a full battery it runs 3 ceiling fans, 6 LED bulbs and a Wi-Fi router for about 9.6 h. During daily load-shedding of 6 h (city pattern), a typical home gets 6.6 h per cut.
Backup by what you run
A 3 kVA UPS (24 V) gives about 2400 W at once. The battery bank holds 4,800 Wh.
| What runs | Uses | Backup |
|---|---|---|
| 2 ceiling fans and 4 LED bulbs | 208 W | 15 h |
| 3 ceiling fans, 6 LED bulbs and a Wi-Fi router | 324 W | 9.6 h |
| A fridge, 2 ceiling fans and 4 LED bulbs | 283 W | 11 h |
| 4 ceiling fans, 8 LED bulbs, a router and a 32-inch TV | 478 W | 6.6 h |
| 6 ceiling fans, 10 LED bulbs, a router and a TV | 662 W | 4.8 h |
| A 1-ton inverter AC and 2 ceiling fans | 860 W | 3.7 h |
| A 1.5-ton inverter AC, 4 ceiling fans and 8 LED bulbs | 1416 W | 2.3 h |
"Too much" means the UPS would trip: it gives about 2400 W at once. A fridge's motor runs about half the time, so it uses less than its rating on average. Figures are for a healthy battery; an old or hot one gives less.
How many fans can it run?
Up to about 30 ceiling fans of 80 W at once, if nothing else is on. More fans means less time:
| Fans | Backup |
|---|---|
| 1 fan | 34 h |
| 2 fans | 18 h |
| 3 fans | 13 h |
| 4 fans | 9.7 h |
| 6 fans | 6.6 h |
| 8 fans | 5 h |
| 10 fans | 4 h |
| 12 fans | 3.3 h |
Real backup during load-shedding
For a typical home: 3 ceiling fans, 4 LED bulbs, a Wi-Fi router, 2 phones charging, a fridge and a 32-inch TV in the evening.
| Cuts | Pattern | Stays on | Per cut |
|---|---|---|---|
| Light | 4 h a day | 4 h of 4 h | 6.8 h |
| City | 6 h a day, 1 h every 4 h | 6 h of 6 h | 6.6 h |
| Heavy | 10 h a day, 2 h cuts | 10 h of 10 h | 6 h |
| Rural | 16 h a day, 4 h off and 2 h on | 5.8 h of 16 h | 1.4 h |
With city load-shedding everything stays on through every cut: the charger refills the battery between cuts. Longer daily cuts are where it starts to fall short.
Open this setup in the planner
The planner opens with this UPS and battery and a typical home's appliances; change anything to see your own backup.
Other setups
- 1 kVA UPS with 150 Ah battery: backup time
- 1 kVA UPS with 185 Ah battery: backup time
- 1 kVA UPS with 200 Ah battery: backup time
- 1.5 kVA UPS with 2 × 200 Ah batteries: backup time
- 3.6 kW hybrid inverter with 2.5 kWh lithium: backup time
- 6 kW hybrid inverter with 5 kWh lithium: backup time
- UPS battery backup time chart (every size at a glance)
Figures are from LoadReserve's calculation with typical values; see how it works.
Last updated .