This is one of those questions that comes up periodically and to be honest, there’s no right or wrong answer. For every answer that there is out there, there are arguments against it. It tends to be controversial. And when I make my case here, I know there are going to be people who disagree with me.
I think that whatever you do will be just fine. I’ll explain why.
Remove the battery to lengthen its life
There’s always a possibility that leaving your battery in the machine when it’s plugged in may shorten the life of your battery.
Actually, it’s better for the batteries to get drained, but not all the way to zero. Ideally, you want to drain them to 20% or 50% so that they get recharged. If they’re kept at maximum or nearly full charged all the time, they don’t necessarily hold the charge as long as they would when they were new.
Now, that being said, it’s not as bad as it once was. While battery technology is not increasing in terms of capacity, they are improving battery memory and lifespan issues. For example, in Macintosh laptops, you can’t replace the battery – it isn’t even removable.
With my Macs and PC laptops, I’ve left the battery in all the time. Over the years, battery lifespan does go down; for example, a three-hour battery becomes an hour and a half battery, but that kind of reduction is over two to three years.
Would it have been an hour and a half battery if I discharged periodically? Probably not. It would only be a two-hour battery. Some degradation just occurs naturally. By taking the battery out, you’re probably slowing the that degradation a little bit.
Leaving the battery in to protect the laptop
The one thing that I like about leaving the battery in the laptop is that it’s like having an uninterrupted power supply.
If the power ever goes out, say like in a thunderstorm, your desktop shuts down. You lose your work if you haven’t saved and you have to wait until the power comes back.
On the other hand, if your laptop has a battery (even a very old, very worn-out one that holds a charge for only 10 or 15 minutes), that still acts as enough of a power supply to protect your laptop from power spikes, power loss, and similar issues. That’s kind of a rationalization, but it’s one advantage to having the battery.
So, are you shortening the lifespan somewhat? Probably. Is it a big deal? Not in my opinion.