Inverter and battery care for Nellore power cuts: water, sizing, loads

Nellore gets long power cuts in summer, often in the afternoon heat and again in the evening. An inverter is how most homes get through them, and the battery is the part that decides whether it lasts an hour or four. Batteries here die early for two reasons: heat, and being run down hard and often. Both are manageable with a few habits.

Sizing, loads and water are the three things that matter. Everything else is housekeeping.

Sizing: VA for the load, Ah for the hours

The inverter's VA rating sets how much you can run at once. The battery's Ah rating sets how long. Roughly, a fan is 70–80 W, an LED tube or bulb under 20 W, a TV 60–120 W, a router and a few chargers another 30 W. Two fans, four lights, a TV and the router is comfortably under 400 W — fine for a common home inverter.

What it cannot do: geyser, iron, induction, mixie, microwave, AC, a 1 HP borewell motor. Those loads are either far above the inverter's rating or have a starting surge that trips it. A fridge is a maybe — it depends on the inverter's surge capacity — and many people are surprised how fast it eats backup.

For hours, a single 150 Ah tubular battery gives several hours of the light load above; two batteries double that but need an inverter rated for two. If cuts in your locality routinely run three or four hours, say so when the system is being chosen; sizing for the actual cut, not the brochure, is the whole point.

Water: the job that keeps batteries alive

Tubular batteries lose water as they charge, and lose it faster in heat. A battery in a Nellore garage in May is working in 40°C-plus air.

• Check the float indicators monthly; every two to three weeks in summer.
• Top up with distilled or battery-grade water only. RO water is not distilled water. Tap and borewell water here is hard and will ruin the plates.
• Fill to between the min and max marks. Overfilling causes acid to overflow and corrode the terminals and trolley.
• Keep the vent plugs clean and seated.
• Wipe the top of the battery. A damp, dirty top lets current track between terminals and drains it slowly.
• Keep the terminals clean and lightly greased with petroleum jelly.

If a cell is drinking much more water than the others, or one float sits low all the time, that cell is failing.

Where it lives

Batteries give off hydrogen while charging, so the inverter and battery should be in a ventilated spot — not inside a closed cupboard or wardrobe, and not in a small bedroom with the door shut. Keep it off the floor on its trolley, especially on a ground floor in a locality that takes water in the October–December rains. Away from children, out of direct sun, and not beside the gas cylinder.

Habits that extend life

• Do not run it flat on purpose. Deep discharge every day is what ages a battery fastest; switch off non-essential loads early in a long cut.
• Let it charge fully after a cut before the next one if you can.
• Use the inverter's ECO or UPS mode as the manual says; for computers use UPS mode, otherwise ECO is gentler on the battery.
• If the house will be empty for weeks, switch the inverter off at its switch and, for long absences, disconnect the battery.

Signs the battery is going

Backup time has dropped sharply; the inverter goes to low-battery alarm soon after a cut starts; white or green crust on the terminals that keeps coming back; a bulging or warm case; water use that has climbed; a sour, rotten-egg smell near it. Any of the last three means stop using it and get it seen.

What to leave to the technician

Changing the battery, re-wiring which circuits run on the inverter, checking the connection between inverter and the distribution board, and a load test. Do not bridge batteries of different ages or ratings, do not add a second battery to an inverter rated for one, and do not wire new rooms onto the inverter yourself — the inverter circuit must be separated properly at the board so it cannot feed back into the mains.

On our rate card Inverter / UPS — battery swap, wiring, load test — is ₹499, with the battery and any parts at MRP shown before fitting.

When to call

Backup that has halved; an inverter that beeps or trips on a normal load; any smell, heat or bulging; or if you want the fridge or more rooms on backup and are not sure the setup can take it. A load test before summer is cheaper than finding out during the first four-hour cut in April.