I recently bought a second-hand HP EliteBook 840 G5. My previous laptop's battery degraded badly, and I'm worried it happened because I left the laptop plugged in for nearly two days. Is it safe to use this laptop while it's charging, or should I unplug it once it reaches full charge? What habits actually help preserve a modern laptop battery?
3 Answers
Yes, you can safely use the laptop while it’s plugged in. Modern laptops stop actively charging once the battery reaches its limit and can run from the charger instead. Leaving it plugged in for two days by itself probably didn’t destroy your old battery.
The 20–80% range is a useful guideline, not a strict requirement. Charging to 100% occasionally is fine, and you don’t need to wait for the battery to run down before charging it. For a used laptop, the battery may already have some wear, so checking its health in HP diagnostics or the operating system is more useful than worrying about one long charging session.
The biggest things that wear down lithium-ion batteries are heat and spending long periods at 100% charge. Keep the laptop’s overall temperature reasonable, make sure the vents aren’t blocked, and use HP’s battery health or charging-limit settings if they’re available. A lower maximum charge, such as around 80%, can help if the laptop stays plugged in most of the time.
I kept seeing advice about the 20–80% rule. Is that something I need to follow strictly?
Try not to let the battery get extremely hot, especially during demanding work or gaming. Heat matters more than whether it was plugged in for a single day.