How long will a 1 kVA UPS with a 185 Ah tubular battery last?
From a full battery it runs 3 ceiling fans, 6 LED bulbs and a Wi-Fi router for about 4.4 h. During daily load-shedding of 6 h (city pattern), a typical home gets 47 min per cut.
Backup by what you run
A 1 kVA UPS (12 V) gives about 800 W at once. The battery bank holds 2,220 Wh.
| What runs | Uses | Backup |
|---|---|---|
| 2 ceiling fans and 4 LED bulbs | 208 W | 6.7 h |
| 3 ceiling fans, 6 LED bulbs and a Wi-Fi router | 324 W | 4.4 h |
| A fridge, 2 ceiling fans and 4 LED bulbs | 283 W | 5 h |
| 4 ceiling fans, 8 LED bulbs, a router and a 32-inch TV | 478 W | 3 h |
| 6 ceiling fans, 10 LED bulbs, a router and a TV | 662 W | 2.2 h |
| A 1-ton inverter AC and 2 ceiling fans | 860 W | Too much: needs 860 W |
| A 1.5-ton inverter AC, 4 ceiling fans and 8 LED bulbs | 1416 W | Too much: needs 1416 W |
"Too much" means the UPS would trip: it gives about 800 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 10 ceiling fans of 80 W at once, if nothing else is on. More fans means less time:
| Fans | Backup |
|---|---|
| 1 fan | 16 h |
| 2 fans | 8.5 h |
| 3 fans | 5.9 h |
| 4 fans | 4.5 h |
| 6 fans | 3 h |
| 8 fans | 2.3 h |
| 10 fans | 1.8 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 | 3 h |
| City | 6 h a day, 1 h every 4 h | 4.5 h of 6 h | 47 min |
| Heavy | 10 h a day, 2 h cuts | 3.5 h of 10 h | 35 min |
| Rural | 16 h a day, 4 h off and 2 h on | 2 h of 16 h | 31 min |
With city load-shedding the battery never gets enough time on the grid to refill, so each cut starts emptier until it settles: a full battery would give 3.6 h, but the real backup is 47 min per cut. That is the recharge gap.
What would make it last longer
For the same typical home on city load-shedding (now 47 min per cut):
- A lithium battery of the same size (the UPS must support lithium): 3.5 h per cut, covering 6 h of 6 h.
- A bigger battery bank (200 Ah): 47 min per cut, covering 4.5 h of 6 h.
- 1 kW of solar panels: 2.9 h per cut, covering 6 h of 6 h.
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 200 Ah battery: backup time
- 1.5 kVA UPS with 2 × 200 Ah batteries: backup time
- 3 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 .