Laptop batteries wear out. It's normal — they're consumable parts, and after a few hundred charge cycles they simply hold less than they used to. The tricky part is knowing when a fading battery has crossed from "a bit annoying" into "replace it now." Here are the signs worth paying attention to.
1. It drains fast, even from a full charge
The most obvious one. If you used to get six or seven hours and now you're scrambling for a charger after ninety minutes, the battery's capacity has dropped. A little decline every year is expected. A sudden or severe drop isn't.
2. It shuts down at 30% or 40%
A healthy battery runs down to a low percentage before the laptop sleeps. A tired one can misread its own charge and cut out early — you're at 35% and the screen goes black with no warning. That's a strong sign the cells are failing.
3. It only works plugged in
If unplugging the charger instantly kills the machine, the battery is barely holding anything at all. Some people run a laptop like this for months, but it turns a portable computer into a desktop that dies in every power cut.
4. The battery is swollen
This one matters for safety, not just convenience. If the trackpad feels raised, the case is bulging, or the laptop rocks on a flat desk, stop using it and bring it in. A swollen battery is a genuine hazard and shouldn't be left in the machine.
5. Your system reports poor battery health
On a Mac, hold Option and click the battery icon, or check System Settings, then Battery, then Battery Health. On Windows, open a command prompt and run powercfg /batteryreport to see design capacity versus current capacity. If the current figure is well below the original, the numbers confirm what you're feeling.
Worth replacing, or worth replacing the laptop?
On most machines a battery swap is quick and far cheaper than a new computer, so it's usually worth it if the rest of the laptop is fine. On a very old machine with other problems, it may not be. We'll always give you an honest answer as part of the fixed quote rather than pushing a replacement you don't need.
If you've spotted any of these signs, we handle battery replacement for laptops and MacBooks — see our Mac Battery Replacement page, or just contact us and we'll check the battery's real health for you.
Need a hand with this?
Free diagnostics (2–4 days) or express for 600 kr (1–2 hours). Fixed quote before we start.