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I’ve had a hard time finding any information about this on the web, so sharing what I’ve found in case anyone else finds this useful.

Although I’m a developer and casual gamer, I tend to try to be frugal and have a tendency to replace my computers rather infrequently. This article is written on a laptop around 8 years old, and my gaming computer is only about a year newer.

So with a computer so old, it’s not too surprising that the battery completely failed. As in - the laptop would die instantly if unplugged. It was so bad, that if there was a momentarily blip of the power at my house, my gaming computer, with no battery backup at all, would stay running while the laptop shut off.

The Issue

When the battery fails this badly, it causes a very odd issue in Windows: Lag.

When the computer is first booted, it will briefly hang every few seconds, and ignore all input during that time. Mouse movements and keyboard inputs where both skipped.

This makes the computer almost impossible to use, but fortunately, if the computer is left running, the lag eventually goes away and the computer is usable again.

I’m not sure exactly how long this takes, but my guess is that it’s between 1-2 hours.

I’m unsure of the exact method by which is happens or stops happening, but my assumption is that battery state interrupts the OS, so that it can display messages to the user or shutdown when the battery gets too low. When the battery is too dead, it tries to cycle between charging and not charging too quickly which interrupts the OS so frequently that it causes a noticable delay to the user.

Windows must have some kind of a timeout that eventually stops trying to charge, but this doesn’t happen until a certain number of recharge cycles are attempted and fail. Or perhaps it’s due to logging, and Windows stops logging after the logfile grows too large?

Lag detector tools will not catch this issue.

I’ve experienced this same issue on two different laptops from two different manufacturers and in both cases removing or replacing the battery fixed the issue.

I don’t know if Linux or MacOS experience the same issue, I haven’t tried.


If your battery is dead and your computer is laggy after boot buy a new battery or remove it.

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