With the power cuts we get in Rohtas, an inverter battery works harder than the makers ever assumed. Water topping, heat, ventilation, honest load sizing — the handful of habits that decide whether a battery lasts its life or half of it.
An inverter battery in this part of Bihar does not have an easy life. Between April and June the room it sits in crosses 40°C for weeks. Cuts are frequent and long, so it is discharged deeply and often. Voltage sags in the evening, so charging is slower than it should be. Then the monsoon arrives and the terminals corrode.
Batteries do fail on their own eventually. But most of the ones we are called to look at in Sasaram and Dehri-on-Sone did not fail on their own — they were dried out, cooked, overloaded or left standing. Almost all of that is avoidable.
Water topping is the whole game
If you do one thing, do this. A flooded lead-acid battery loses water every time it charges, and it loses more in our heat. When the plates are no longer fully covered, the exposed part starts to sulphate and that capacity does not come back.
Check the level through the float indicators or the filler caps. In the hot months you will need to check more often than in winter — how much more depends on your battery and how hard it is being worked, so look every few weeks rather than following a fixed rule. Top up only with distilled water, never with tap water, RO reject water or hand-pump water. The groundwater in parts of Rohtas and Kaimur carries a lot of iron and dissolved salts, and pouring that into a battery ruins the plates.
Fill to the marked upper level and no higher. Overfilling makes acid spill out during charging, which corrodes the terminals and the tray. And do the topping up with the inverter switched off, wearing something you do not mind ruining.
Handle the acid with respect: battery electrolyte is dilute sulphuric acid, and a charging battery gives off hydrogen, which is explosive. Never bring a flame, a lit cigarette or a spark near the battery, never lean over the vents while topping up, and switch the inverter off first. If electrolyte touches skin or eyes, flush with plenty of clean water immediately.
Terminals and corrosion
The white or greenish crust that grows on terminals is not cosmetic. It adds resistance, so charging current drops and the battery never quite reaches full. Over months, that alone will finish a good battery.
Keep the top of the battery dry and clean. A loose terminal is worse than a dirty one — it heats up, sparks under load and can melt the post. Tighten the connections, and if you see heavy corrosion or a terminal that has started to deform, get it looked at rather than hammering it back into shape. Cleaning terminals means disconnecting them in the right order, so if you are not sure, do not guess.
Heat and ventilation
Heat is the second biggest killer after low water. A battery run hot ages faster, uses up water faster and loses capacity permanently. In a Bihar summer the battery is already near its limit before it does any work.
So think about where it stands. It wants a shaded, ventilated spot with air on all sides, off the floor on its trolley or stand, and away from a wall that bakes in the afternoon sun. It should not be in a sealed cupboard, under a staircase with no air movement, shut into a store room, or in a bedroom — the gas it gives off while charging needs somewhere to go.
Also keep it out of the rain and away from splashing. Damp on the top of a battery creates a leakage path between the terminals that quietly drains it.
Size the load honestly
Most disappointing backup is not a battery fault at all. It is a battery being asked to do a job it was never bought for.
Work out what you actually want running in a cut — some lights, fans, the router, a TV perhaps — and match the battery and inverter to that. A fridge, a geyser, a motor, a microwave or an AC are a different class of load altogether, and connecting them to a domestic inverter will either trip it or flatten the battery in minutes while shortening its life every time.
A related trap: the deeper you discharge a battery routinely, the fewer cycles you get from it. Running it flat every night, which is easy to do in June when cuts are long, wears it out far faster than the same battery used gently.
Tubular or flat plate
The two common types suit different situations, and the honest answer depends on how many hours of cut you get.
| Point | Flat plate | Tubular |
|---|---|---|
| Suits | Short, occasional cuts | Frequent, long cuts |
| Deep discharge | Tolerates it poorly | Built for repeated deep cycling |
| Behaviour in heat | More sensitive | Handles sustained heat better |
| Water consumption | Needs topping up more often | Longer gaps between top-ups |
| Physical size | Lighter, smaller | Heavier, bulkier |
| Upfront cost | Lower | Higher |
| Realistic life here | Shorter under our cut pattern | Longer if maintained |
For most households across Rohtas, Kaimur and Aurangabad, where cuts are routine rather than rare, tubular is the sensible choice and usually works out cheaper across its life even though it costs more on the day. A flat plate battery makes sense where cuts are short and the backup is a convenience rather than a necessity. Sealed maintenance-free batteries avoid the topping-up job, but they are unforgiving of heat and cannot be revived once neglected.
Signs a battery is on its way out
- Backup time drops noticeably over a few weeks with no change in what you run.
- It charges very quickly and empties just as fast — the capacity has gone.
- The inverter alarms or cuts out soon after a power failure.
- The case has swollen or bulged anywhere.
- Water needs topping up far more often than it used to, or one cell always runs dry first.
- A strong sulphur smell, visible leakage, or heavy heat at the battery while charging.
A swollen case or a leaking battery should be taken out of service. That one is not a repair, and it is not worth nursing along.
Not every weak backup means a dead battery, though. Low water, a corroded terminal, a faulty charging section in the inverter or simply months of low evening voltage can all mimic a failed battery. It is worth having it tested before buying a new one — we would rather tell you the battery is fine and the terminal was loose.
Monsoon, idle periods and the festival season
The rains bring their own problems: damp on the battery top, corrosion at the terminals, and surges from lightning that can damage the inverter's electronics. During a heavy thunderstorm it is sensible to switch the inverter off at the mains rather than leaving it charging.
If a house is going to be locked up for weeks, do not simply switch everything off and walk away. A lead-acid battery left standing discharged sulphates and may never recover. Leave the inverter charging where that is practical, or ask an electrician how to leave the system for the period you are away.
Before Chhath and Diwali, when the load on the house goes up and nobody wants backup failing, it is worth a check of water levels, terminals and connections. Our electrical work is listed on the services page, with current charges on the rate list — GST extra, spare parts billed at actual cost after we tell you, and a bill for every job.
We attend inverter and battery work in Sasaram, Dehri-on-Sone, Bikramganj, Kudra and Aurangabad, with same-day visits across Rohtas, Kaimur and Aurangabad districts and scheduled visits elsewhere. Book through the contact page and we call back within an hour, or ring +91 96315 11974 between 8:00 AM and 6:30 PM.
Frequently asked questions
There is no fixed interval, because it depends on the battery and how hard it works. In a Bihar summer, with long cuts and high room temperature, it consumes water noticeably faster than in winter. Check the level every few weeks, top up only with distilled water, fill to the marked upper level, and do it with the inverter switched off.
No. Only distilled water. Tap water, hand-pump water and RO reject water carry iron and dissolved salts, and groundwater in parts of Rohtas and Kaimur is particularly hard. Those minerals settle on the plates and permanently reduce capacity. Distilled water is easily available and is the cheapest part of keeping a battery alive.
Check the simple things first: water level low, a corroded or loose terminal, or more load added than before. Long cuts that flatten the battery every night also reduce backup over time. If the battery charges fast and empties fast, its capacity has gone. Get it tested before replacing it, since a faulty charging section can look identical.
For most homes in Rohtas, Kaimur and Aurangabad, where cuts are frequent and long, tubular suits better because it is built for repeated deep discharge and handles our heat more comfortably. Flat plate costs less and is fine where cuts are short and occasional. Judge by your actual cut pattern, not by the price tag alone.
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