Symptom guides · Singapore
Signs your laptop battery needs replacing (and one that means stop now)
Two free numbers tell you whether your battery is finished. A third sign tells you to stop using the machine immediately. Most people watch none of them.
On this page
The sign that means stop today
If the laptop rocks on a flat table, the base has bowed, the trackpad has stopped clicking properly, or the screen is lifting away from its frame at an edge — the battery is swollen. That is a lithium-polymer cell whose electrolyte has decomposed into gas. It is pressurised, its separator may be compromised, and puncturing or crushing it causes a fire that water will not put out.
Power the machine down. Unplug the charger. Do not press the bulge flat, do not put it in a bag, do not leave it on a bed or sofa. Put it on a hard, non-flammable surface away from anything that burns, and bring it in the same day. This is the one repair we ask people not to postpone. Full guidance on the battery page.
The two numbers, and how to read them
Cycle count. One cycle is one full discharge worth of energy, not one plug-in. Charging from 70% to 100% four times is one cycle. Most modern packs are rated for 500 to 1,000 cycles before falling to about 80% of design capacity.
Full charge capacity versus design capacity. If your pack was designed for 57,000mWh and now reports 31,000mWh, you have 54% of the battery you bought — and 54% of the working day.
- Windows: open Command Prompt, run
powercfg /batteryreport, and open the HTML file it names. Both numbers are there. - macOS: hold Option, click the Apple menu, choose System Information, then Power. Apple publishes the rated cycle maximum for every Mac notebook.
Below roughly 70% of design capacity, or past the rated cycle count, replacement is reasonable. Below 60%, it is overdue.
Five behavioural signs
- Sudden shutdowns above 20%. The pack cannot supply peak current under load; the voltage sags and the machine drops out. Often mistaken for a software fault.
- Charge percentage that jumps. 60% to 12% in a minute means the fuel gauge has lost track of a collapsing cell.
- Runtime halved in a year. Normal ageing takes three to five years to do that. A year means heat, or a pack that was never what it claimed.
- The machine only runs when plugged in. The pack, its protection board, or the charging circuit. Not always the pack — see below.
- It gets hot doing nothing. A cell with internal resistance rising heats itself, which raises the resistance further. Get it looked at.
Not sure what you are looking at? Ask a technician.
Send us the model and a two-line description of the symptom. You will get a probable diagnosis and an honest price band before you leave the house.
When it isn't the battery
Roughly a quarter of the machines that arrive here for a battery leave with their original pack. "Plugged in, not charging" is a message about a charge path, and that path runs from the DC jack or USB-C port, through input protection, into a charging IC, into the pack's protection board, and back to a battery management controller.
A failed charging IC, a worn DC-in jack, a corroded battery connector after an old spill, or a third-party charger negotiating the wrong power profile all produce symptoms identical to a dead battery. We read the pack's own telemetry over its SMBus and measure the charge rail before quoting a pack. Ask whoever is quoting you whether they have done the same.
What replacement costs, and what the pack should be
- Mainstream laptop — S$120 – 200, same day, 30–60 minutes.
- Thin ultrabook, adhered pack — S$180 – 300, 2–4 hours.
- Gaming laptop, 80–99Wh — S$200 – 340.
- MacBook — S$190 – 380.
- Charging IC repair, pack retained — S$140 – 280.
Ask one question of any shop: what rated capacity, in watt-hours, is the pack you are fitting? A replacement sold for a 57Wh original that quietly contains 41Wh of cells is not a bargain; it is a 28% shorter working day. We print the figure on the job sheet.
Making the next pack last twice as long
Cap the charge at 60–80% whenever the machine lives on a desk. Every major manufacturer ships the setting: Lenovo Vantage Conservation Mode, Dell Power Manager, MyASUS Battery Health Charging, HP Battery Health Manager, Razer Synapse, and Optimised Battery Charging on macOS.
Then keep it cool. Lithium cells age fastest hot and full, and a laptop on a duvet is both. Shallow cycles between roughly 30% and 80% are gentler than deep ones. Store a laptop near 50% charge, not full and not empty. And service the cooling — a clean fin stack keeps the pack cool as a side effect, which is one more reason a thermal service pays for itself twice.
Questions we get every week
Frequently asked questions
How many years should a laptop battery last?
Three to five years of ordinary use, or 500 to 1,000 charge cycles, before capacity falls to about 80% of design. Heat and being kept at 100% charge both shorten that considerably — a docked gaming laptop can halve it.
Is it safe to use a laptop with a swollen battery?
No. Stop using it, stop charging it, and do not compress or puncture the pack. A swollen lithium-polymer cell is pressurised with decomposition gas. Put the machine on a hard non-flammable surface and bring it in the same day.
Should I leave my laptop plugged in all the time?
Plugged in is fine. Plugged in at 100% and warm is what ages the cell. Use your manufacturer's charge limiter to cap at 60–80% for desk use and the pack will very likely outlive the laptop.
Are third-party laptop batteries safe?
A reputable pack with genuine cells from a named manufacturer and a proper protection board is safe. An unbranded pack at half the going rate has neither, and those are the ones that swell in fourteen months. Ask for the cell brand and the rated watt-hours in writing.
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Get a written quote before a screw turns
Component-level diagnostics, a fixed price in writing, and no repair fee if we cannot fix it. Walk in Mon–Fri, or WhatsApp the workshop.