7 signs your laptop battery needs replacing

Laptop batteries don't last forever. They are consumable parts, and every full charge and discharge wears them down a little. Most laptop batteries are designed for a few hundred to around a thousand charge cycles, which usually works out to somewhere between two and five years of normal use. Heat, constant charging and deep discharges can shorten that.

With load shedding and unreliable power still part of life in South Africa, a healthy battery matters more here than in many places. It is what keeps you working when the lights go out. These are the signs we see most often in our Durban workshop that a battery is on its way out.

1. The battery is swelling

This is the one sign you should never ignore. A swollen lithium-ion battery can push up the keyboard or trackpad, make the laptop rock on a flat table, or cause the bottom panel or screen hinge area to bulge or separate.

2. The charge drops much faster than it used to

If a laptop that once lasted a full morning now needs the charger after an hour, the battery has lost a large share of its original capacity. Some drop is normal over time. A sudden or severe drop usually means the cells are worn.

3. It shuts down suddenly, even with charge showing

A worn battery can report 30% or 40% remaining and then switch off without warning when you open a heavy program. This happens because the battery can no longer deliver enough power under load, and it is a clear sign that it needs replacing before you lose unsaved work.

4. It only works when plugged in

If your laptop dies the moment you unplug the charger, the battery is either completely worn out or has failed. The laptop may keep working on mains power, but you have lost all protection against power cuts, and a failing battery can still cause other problems while installed.

5. Windows or macOS warns you

Your operating system keeps track of battery health. A red cross or warning on the battery icon, or a message such as "Consider replacing your battery" or "Service recommended", should be taken seriously.

6. The battery gets unusually hot

Laptops get warm, but a battery area that becomes hot to the touch during light use or while charging is not normal. Heat speeds up battery wear, and excessive heat can point to a failing cell.

7. The percentage jumps around

If the charge level jumps from 50% to 20%, or stays stuck at the same percentage for hours, the battery's internal measurement is no longer reliable. This is common in older batteries and usually comes before other symptoms.

How to check your battery's health

On Windows

1. Right-click the Start button and open Terminal, Windows PowerShell or Command Prompt.
2. Type powercfg /batteryreport and press Enter.
3. Windows saves a file called battery-report.html and shows you where. Open it in your browser.
4. Compare the Design capacity with the Full charge capacity. If the full charge capacity is well below the design capacity, the battery has worn.

On a MacBook

Open System Settings, go to Battery and look at Battery Health. If it says "Service Recommended", the battery should be replaced. Holding the Option key and clicking the Apple menu, then System Information > Power, also shows the cycle count and condition.

Is a new battery worth it?

Usually, yes, if the rest of the laptop is in good shape. A replacement battery costs far less than a new laptop, and if you pair it with an SSD upgrade, an older machine can feel new again. It may not be worth it if:

• the laptop is very old and too slow for what you need even when plugged in;
• there are other major faults, such as a failing motherboard or badly damaged screen;
• parts for that model are no longer available.

We will always tell you honestly which side of that line your laptop is on before any work is done.

How to make your next battery last longer

• Keep it cool. Don't leave the laptop in a hot car or charge it on a bed or couch where the vents are blocked.
• Avoid running it flat regularly. Lithium-ion batteries prefer partial charges to full drain-and-recharge cycles.
• Use battery-care settings. Many laptops from Lenovo, HP, Dell, Asus and Apple can limit charging to around 80% when the laptop is mostly plugged in at a desk.
• Use a good charger. Cheap, unbranded chargers can damage the battery and the laptop.
• Protect against surges. Power surges when electricity comes back after load shedding can damage chargers and laptops. A surge protector or UPS is a small investment.