Home / Backup time / 200Ah with TV night
A 200Ah 12V tubular battery runs TV + set-top box + 2 fans + 3 lights for about 3 hours 28 minutes. That load averages 242W, and the battery holds 840Wh usable once you apply 70% inverter efficiency and the 50% depth of discharge lead-acid batteries are limited to. 840Wh / 242W = 3.5 hours.
The evening serial does not stop for load shedding. Duty cycle matters here: Battery Buddy multiplies each appliance by the minutes it actually runs in an hour, so a fridge that cycles 40 minutes an hour is counted at two-thirds of its nameplate wattage instead of full blast.
| Appliance | Watts each | Qty | Minutes per hour | Average draw |
|---|---|---|---|---|
| LED TV (32-inch) | 60W | 1 | 60 min | 60W |
| Set-Top Box | 15W | 1 | 60 min | 15W |
| Ceiling Fan | 70W | 2 | 60 min | 140W |
| LED Bulb | 9W | 3 | 60 min | 27W |
| Total average hourly load | 242W |
On paper a 200Ah 12V battery stores 200 x 12 = 2400Wh. You never get that. Lead-acid tubular plates are rated for roughly 50% depth of discharge, and the inverter loses more converting DC to AC, so the honest figure is 200 x 12 x 0.7 x 0.5 = 840Wh.
Large tubular for 3BHK homes, shops and clinics. If you have already measured your own system with the efficiency estimator, put your real factor into the calculator — that single number moves the answer more than any other input.
At 3 hours 28 minutes this is a Moderate Load setup — it clears the 2-hour danger line but stays under 5 hours, so a long monsoon outage will need you to shed something.
Runtime and capacity are two different questions. With every appliance on at once this profile draws 242W continuous, which sizes to (242W / 0.8) x 1.25 on average draw and lands on a standard 600VA inverter.
The start-up surge test is the one most calculators skip. Ceiling Fan spikes to about 210W for a second or two when its motor kicks in, so peak demand is 242W continuous + 210W surge = 452W. Against a 600VA inverter that is 25% headroom — it holds.
Battery age, electrolyte level, cable thickness and terminal corrosion all show up as one thing: a lower effective efficiency. Here is the same battery and the same load across the realistic range.
| System efficiency | Usable energy | Estimated backup |
|---|---|---|
| 55% | 660Wh | 2 hours 44 minutes |
| 60% | 720Wh | 2 hours 59 minutes |
| 65% | 780Wh | 3 hours 13 minutes |
| 70% (default) | 840Wh | 3 hours 28 minutes |
| 75% | 900Wh | 3 hours 43 minutes |
| 80% | 960Wh | 3 hours 58 minutes |
Run the two-hour test on the efficiency estimator to replace this guess with your own measured factor.
If you are still choosing a battery, this is the whole shelf against exactly this load.
| Battery | Usable energy | Estimated backup | Band |
|---|---|---|---|
| 100Ah | 420Wh | 1 hour 44 minutes | High load |
| 120Ah | 504Wh | 2 hours 5 minutes | Moderate |
| 135Ah | 567Wh | 2 hours 21 minutes | Moderate |
| 150Ah | 630Wh | 2 hours 36 minutes | Moderate |
| 165Ah | 693Wh | 2 hours 52 minutes | Moderate |
| 180Ah | 756Wh | 3 hours 7 minutes | Moderate |
| 200Ah (this page) | 840Wh | 3 hours 28 minutes | Moderate |
| 220Ah | 924Wh | 3 hours 49 minutes | Moderate |
| 250Ah | 1050Wh | 4 hours 20 minutes | Moderate |
And this is the same 200Ah battery against every other load profile we model.
| Load profile | Average draw | Estimated backup |
|---|---|---|
| 2 ceiling fans + 3 LED bulbs | 167W | 5 hours 2 minutes |
| 1 ceiling fan + 2 LED bulbs | 88W | 9 hours 33 minutes |
| 3 ceiling fans + 5 LED bulbs | 255W | 3 hours 18 minutes |
| 2 fans + 4 lights + TV + WiFi router | 246W | 3 hours 25 minutes |
| Refrigerator + 2 fans + 4 LED bulbs | 276W | 3 hours 3 minutes |
| Laptop + WiFi router + 1 fan + 2 lights | 163W | 5 hours 9 minutes |
| 2 fans + 6 lights + TV + refrigerator + WiFi | 404W | 2 hours 5 minutes |
| Air cooler + 2 LED bulbs | 198W | 4 hours 15 minutes |
| 4 tube lights + 2 fans + billing computer | 420W | 2 hours |
| 1 fan + 2 lights + 2 mobile chargers | 98W | 8 hours 34 minutes |
| TV + set-top box + 2 fans + 3 lights (this page) | 242W | 3 hours 28 minutes |
| 3 BLDC fans + 6 LED bulbs | 144W | 5 hours 50 minutes |
About 3 hours 28 minutes. The load averages 242W and the battery delivers 840Wh usable at 70% efficiency and 50% depth of discharge, so 840 / 242 = 3.5 hours.
Because 70% is an assumption, not your measurement. A battery two or three years old, a low electrolyte level, thin cabling or a charger that never completes a cycle in short grid windows all pull the effective factor down. At 55% the same setup gives 2 hours 44 minutes. Measure yours with the efficiency estimator.
A standard 600VA inverter. The sizing rule is (average load / power factor 0.8) x 1.25 safety margin, which on 242W gives 378VA and rounds up to the nearest retail tier.
No. Lead-acid tubular batteries are rated for roughly 50% depth of discharge — draining past half state of charge sulphates the plates and shortens life sharply. That is why 200Ah x 12V = 2400Wh nominal becomes 840Wh usable.
Cut the load, not the comfort. Replacing induction ceiling fans with 30W BLDC fans and any remaining CFLs with 9W LEDs typically removes 40-45W per fan and 6W per bulb. On this profile that is the difference between 3 hours 28 minutes and materially more, at a fraction of the cost of a second battery.
No. Battery Buddy is a free, brand-neutral calculator from Flocci Technologies. It shows the formula for every number so you can check it against any dealer's quote, and it needs no sign-up.
Battery Buddy is free, needs no sign-up, sells no batteries and shows every formula it uses. It is built by Flocci Technologies, an India-first AI-native software studio behind 30+ apps that share one Flocci identity.