My laptop battery goes from 100 percent to dead in two hours. It used to last six. What is happening and can I fix it

[Clever Wrench]

Q: Three year old laptop. Battery used to last six hours, now dies in under two even on light use. Battery health shows 61 percent in Windows. Is this just battery degradation and do I need to replace it, or is something draining it that I can fix?

No obvious background processes eating CPU

[Scholar]

61 percent battery health after three years is significant degradation but not unusual. Lithium batteries typically lose around 20 percent capacity per year under normal use. At 61 percent you have lost nearly 40 percent of original capacity

[Nina24]

The maths is simple: if original capacity was 6 hours and you now have 61 percent of that capacity you should be getting around 3.6 hours. Getting under 2 hours suggests either the health reading is worse than 61 percent in practice or something is consuming extra power

[CosmicRay67]

Check Power Options in Windows and make sure you are not accidentally running on High Performance mode. Balanced or Power Saver mode makes a significant difference to battery life

[BiscuitTin46]

Run powercfg /batteryreport from an admin command prompt. It generates a detailed HTML report showing your battery history, capacity over time, and recent drain events

[QuantumFoam]

Check for background processes that might have appeared recently. A new app that runs at startup and phones home, a Windows Update stuck downloading, or Windows Defender doing a full scan can all hammer battery life

[Finley]

Display brightness is the biggest single factor most people overlook. Running at full brightness versus 50 percent can reduce battery life by 30 to 40 percent by itself

[Bright Hermit]

The battery replacement question: laptop batteries are usually 40 to 80 pounds for a genuine or quality third party replacement and fitting is straightforward on most models. iFixit has guides for most laptops. At 61 percent health replacement is probably the right answer

[ParallelSelf99]

Check if the battery bulging at all. A bulging battery is a safety issue and replacement becomes urgent not optional

[Sienna74]

Before replacing check your BIOS for battery care settings. Some laptops have settings that limit charge to 80 percent to extend battery lifespan. If someone enabled this previously you may be getting 80 percent of 61 percent which explains the very short runtime