Swollen Laptop Battery? Complete Guide to Replacement, Care and Safety

Last month, a client from Central rushed in with a MacBook Pro whose trackpad was bulging out and the bottom case was creaking. "It was fine last night — this morning it looks like a pillow!" We opened it up: the battery had swollen like a cushion, nearly bursting the chassis. Lucky he brought it in right away — keep charging a swollen battery and you're risking a fire.

A swollen battery is one of the most common yet most dangerous laptop problems. Here's how to spot it, what to do, when to replace it, and how to keep the next one healthy.

How to tell if your battery is swelling

Not every swollen battery looks like a pillow. Early warning signs include:

Bulging trackpad or keyboard — keys feel "floaty", or the trackpad stops clicking
Wobbly base — the laptop rocks on a flat desk like a seesaw
Gaps in the chassis — the bottom cover no longer sits flush
Battery percentage jumps — drops from 60% to 10% and shuts down
Unusual heat — hot to the touch even when idle

If you notice any of these, don't wait — get it checked.

How dangerous is it, really?

This isn't scare tactics. Lithium batteries swell because gas builds up inside. Left alone, a swollen battery can:

Crack the trackpad, keyboard, or even the display
Catch fire if the pouch is punctured and exposed to air
Swell faster the more you keep charging it

We've seen a client charge a swollen-battery laptop on a nightstand overnight — they woke up to the smell of burning. Luckily nobody was hurt, but the bedsheet was scorched. So: if you suspect swelling, stop using it and stop charging immediately.

What to do step by step

Power off and unplug the charger — no more charging
Don't press or puncture the battery — never try to "let the gas out"; one puncture can start a fire
Place it somewhere ventilated, away from flammables — a tiled floor, not on a bed
Get professional repair ASAP — removing a battery needs proper tools and ESD precautions; DIY attempts often puncture it

Replacement cost: genuine vs third-party?

MacBook (built-in battery): around HK$1,200–2,200 including labour, depending on model year
Windows laptop (built-in): around HK$600–1,400
Removable battery (older models): around HK$300–700, DIY-friendly

Genuine or third-party? Genuine batteries have full protection circuitry and certification — safer and longer-lasting, but 30–50% pricier. Third-party is fine if you choose a reputable brand with warranty; avoid no-name "white label" cells. We only fit batteries with warranty, and every replacement carries a 90-day warranty.

How to make your battery last

Don't stay at 100% on the charger — permanent full charge kills batteries. Enable battery care modes (e.g. Lenovo Conservation Mode, ASUS Battery Health Charging) that cap charging at 60–80% if you mostly work docked
Avoid heat — don't use the laptop on a duvet or sofa where vents are blocked; never leave it in a hot car
Don't run it to 0% — deep discharges wear the battery; recharge around 20%
Check battery health every 2–3 years — Windows: run powercfg /batteryreport; Mac: System Information → Power → cycle count
Storing long-term? Leave it at 50% — not full, not empty

Real case: a whole office fleet needed new batteries

Earlier this year, a design firm in Kwun Tong called us: their 2021-era laptops were "losing charge faster and faster", and two had started bulging. On-site inspection found 5 of 12 batteries already slightly swollen — all from machines permanently docked at 100% with no battery care enabled. We replaced all 12, enabled conservation mode, and taught their IT staff to check battery reports quarterly. They now book us for a preventive check every six months, saving plenty on emergency repairs.

Summary

A swollen battery is no joke: spot the signs, stop using and charging it, and get it replaced promptly. With good habits — no permanent 100% charging, no heat-trapping, regular health checks — a battery can easily last 3–4 years.

If your trackpad is bulging, the base wobbles, or the percentage jumps around, WhatsApp CentralComputer. We cover all of Hong Kong, and most battery replacements are done same-day.

Swollen Laptop Battery? Complete Guide to Replacement, Care and Safety