What if my computer battery doesn't fully charge?

I take it you mean your laptop’s battery pack…

Over time, all laptop (or, notebook if you’re into political correctness) battery packs will hold less charge than they did when they were new. This is the same for nearly every rechargeable battery in the world. This is just something that happens and is unavoidable, but there are a number of things you can do to delay its onset.

You should always charge your battery up fully, run it right down, then charge it back up fully, and so on. You should never leave the laptop plugged in when the battery is fully charged, as this will help the battery to not hold much charge over time. Similarly, you should never half-charge the battery. Lithium Ion batteries work best and last longest with the charge-deplete cycle.

If your battery is not holding as much charge as it once did, you can run the battery right out (as in until your computer runs totally out of power from the battery), then charge it up fully - you should notice that it seems to last longer than it did before for a while. But your battery will eventually die - if it no longer lasts 30 minutes, and you still want to use the laptop for some years, you’d be better off getting a new battery.

So, try running the battery fully down, then charge it up and see if it lasts longer. What type of computer & computer model do you have?