Laptop Shutting Off When On Battery?

[reubenray]

Lately my eight year old Dell laptop has been shutting off even when I have a full battery. I have had to keep it plugged up all the time to keep this from happening. Any idea what is causing this? I replaced the battery about three years ago.

 

[arlo]

A recalibration might be needed. Even if it shows full, the individual cells may have become unbalaced. And the BMS chip in the battery reports false information to the pc.
Try this. Start it up in the bios/uefi and leave it there until the battery dies and it shuts off.
It might just keep running longer than in Windows. Or run for a short while and shut off.
If it's the first case. Probably just needs a balancing. If the latter, the pack might just be dead.
Not throwing stones but perhaps just a cheaply constructed battery with substandard cells. Could be.

Patience. Keep restarting it in bios/uefi until it won't fire up anymore.
Then plug the charger in and let it complete a full charge. And see what happens. If it's better.
Do the same thing one more time. Run it until it dies dead-dead. Then just let it charge, pc shut off.
When charged, it might be better. It might not be.

There are bench jigs that read the actual BMS and override it to let a tech manually monitor and charge the separate packs. They can also reset any "time bombs" in it that cause an otherwise good pack to show bad.
Maybe Santa will be good to me some year.

You might just need a new battery. Maybe the PC power management chip is going. A Dell common thing.
Leaving a laptop plugged in with a full battery is known to reduce the life. Asus for one recommends that you don't leave the charger plugged in all of the time even when shut down. And setting Windows to charge the battery to 85% instead of 100% increases life.
That's all I got.

 

[dishstaller]

That's all I got.

That was quite enough....I definitely learned something from your post. Thanks