A laptop battery needs replacing when it can no longer hold a useful charge: runtime has dropped to a fraction of what it was, the laptop shuts off while the gauge still shows plenty, the built-in battery report shows far less capacity than the design figure, or the case and trackpad are bulging. A bulging battery is urgent. Everything else you can confirm in about five minutes without any tools.
Which warning signs mean the battery is wearing out?
Gradual loss of runtime is the obvious sign, but it's rarely the first one you notice. Batteries usually announce themselves through odd behaviour long before the laptop dies in your bag. The signs below are listed roughly from early to late.
- The percentage jumps. The gauge drops from 50 to 30 in a minute, or climbs after you plug in. The battery's internal sensing no longer reflects what the cells can deliver.
- Sudden shutdowns on battery. The laptop switches off with 20 or 30 percent showing, then boots happily on mains. Worn cells sag under load, and the system shuts down to protect itself.
- It only works plugged in. A laptop that dies the moment you pull the charger has a battery that has effectively stopped storing energy.
- "Plugged in, not charging" or a charge that stalls. This may be the battery or the charging circuit. It needs a few checks, covered below.
- Warmth under the palm rest. A battery that runs hot while idle or charging is under stress.
- A warning from the operating system. Windows can show a "consider replacing your battery" message, and macOS marks the battery "Service Recommended."
- Physical bulging. The trackpad lifts, the keyboard rises, the case seam opens or the laptop rocks on a flat desk.
How can you check battery health on Windows and macOS?
Both systems can report how much charge the battery can hold compared with when it was new. Apple's own benchmark for a consumed MacBook battery is 80 percent of original capacity, which is a sensible yardstick for Windows laptops as well. A reading well below that, combined with short runtime, settles the question.
Windows
- Right-click the Start button and open Terminal or Command Prompt.
- Type powercfg /batteryreport and press Enter. Windows saves an HTML file and prints its location.
- Open the file in a browser and find the "Installed batteries" table.
- Compare Design capacity with Full charge capacity. The gap between them is the wear.
The same report lists recent usage and how long the laptop ran on each charge. Our guide to checking laptop battery health explains how to read the rest of it.
macOS
Open System Settings, choose Battery, then Battery Health to see Maximum Capacity and the condition message. For the charge cycle count, open System Information and look under Power. Apple designs current MacBook batteries to retain up to 80 percent of their capacity at 1,000 complete cycles, so a count well below that with a low capacity figure suggests a faulty cell rather than normal ageing.
Is it the battery, or the charger, port or software?
Rule out the cheap suspects first, because a charger or charging-port fault looks very much like a dying battery. Work through these checks in order, and stop as soon as one explains the symptom.
- Look for swelling. If the case is distorted, skip everything else and read the next section.
- Try a known-good charger with the same voltage and wattage as the original. A weak adapter can charge slowly or not at all.
- Inspect the charging port and plug. Wiggle the plug gently. A loose fit, a hot plug tip or an intermittent charge light suggests a port problem rather than a battery problem.
- Read the battery report. Healthy capacity with poor runtime points away from the battery.
- Check what's draining it. Open Settings, then Power and battery, then Battery usage. A runaway browser tab, sync job or background update can halve your runtime.
- Update the BIOS and chipset drivers. Some gauge faults are firmware bugs, and an update fixes the reading.
If the battery is healthy, the charger is good and the laptop still won't charge, the fault may be on the motherboard's charging circuit. This laptop-won't-charge guide walks through that branch.
What should you do if the battery is swollen?
Stop using and charging the laptop at once. A swollen lithium-ion cell is a fire risk, and the danger rises if it's pressed, punctured, heated or charged. Don't try to flatten it or open the case yourself. Handle it gently and arrange a replacement as soon as you can.
- Shut the laptop down, unplug the charger and leave it on a hard, non-flammable surface.
- Don't carry it in a packed bag or take it on a flight. Keep it away from sunlight and from your bed or sofa.
- Don't press on the bulge or try to use the trackpad if it has lifted.
- Have the battery replaced by a technician and ask that the old pack is disposed of as e-waste.
Our swollen battery guide goes into the causes and the safe handling steps in more detail.
What does a replacement involve and cost?
Replacement means opening the base, disconnecting the old pack and fitting a new one with matching voltage and capacity. Our indicative price range for Windows laptop batteries is ₹1,499 to ₹4,999, and for MacBooks it's ₹3,499 to ₹6,999, with a 90-day warranty. The model and the battery's capacity decide where you land.
On older laptops, the battery clips out in seconds. On most recent thin laptops it's internal, held with screws, and on some it's partly glued down, which takes longer and more care. After fitting, the laptop is charged and discharged to check that the gauge reads sensibly and that the battery holds under load. We cover the pricing in more detail in our Mumbai battery replacement cost guide, and the laptop battery replacement service page lists what's included.
Can you slow the wear on a new battery?
Yes. Heat and sitting at full charge are what age lithium-ion cells fastest. Most manufacturers now include a setting that caps the charge level for desk use. Switch it on if the laptop spends most of its life plugged in.
- Lenovo calls it Conservation Mode, which holds charging at roughly 55 to 60 percent.
- ASUS laptops offer a battery care limit in MyASUS.
- HP has Battery Health Manager in the BIOS or HP software.
- Dell offers charge profiles such as Primary AC Use.
- MacBooks have Optimized Battery Charging.
Also keep the vents clear and avoid charging on a bed or cushion. Our guide on making a laptop battery last longer covers the daily habits.
Frequently asked questions
How long should a laptop battery last before it needs replacing?
There's no fixed age. Wear depends on charge cycles, heat and how the laptop is used, and cells also age chemically while sitting unused. Trust the capacity report, not the calendar.
Can I run my laptop without the battery?
Some models will run on mains alone. Others slow down, shut off or refuse to start. Removing the pack is not a fix for a swollen battery, which should be replaced, not ignored.
Does a third-party battery work as well as the original?
Quality varies widely. Check that the voltage and watt-hour rating match, ask about the warranty and avoid unbranded packs with inflated capacity claims.
Will replacing the battery void my laptop's warranty?
That depends on who did the work and on the warranty terms. Our guide on whether repairs void a laptop warranty explains how to check.
If your report shows heavy wear or the laptop is bulging, book a free doorstep pickup and we'll test the battery and the charging circuit before quoting, so you only pay for the part that has failed.
