Just wanted to share my experience. After owning the 3DS for 6 years, I noticed that I often my 3DS in a state of drained battery despite just charging it the night before. Playing with the 3DS doesnt seem to indicate that the battery itself is dying or not holding charge.
What happened is that the 3DS has been turning itself on and off every minute, over and over again. I thought it must have been the power button being pressed (accidentally) or that the button itself is depressed inward. Tried to disamble the 3DS and look at the power button, clean it with alcohol just to ensure it wasnt dusty or have some weird contact that leaves the button pressed. No luck. The problem persist.
At this point since the 3DS been turning itself on and off a lot, the screen has burnt it with my splashscreen.
The next thing I noticed is a spicy-pillowed/expanded battery.
Replaced that and now the problem seems to be gone. (still not sure which comes first : if the battery expanded because of the on/off OR the on/off is caused by the expanded battery)
My battery looks exactly like this (credit: u/SinisterCryptid)
What happened is that the 3DS has been turning itself on and off every minute, over and over again. I thought it must have been the power button being pressed (accidentally) or that the button itself is depressed inward. Tried to disamble the 3DS and look at the power button, clean it with alcohol just to ensure it wasnt dusty or have some weird contact that leaves the button pressed. No luck. The problem persist.
At this point since the 3DS been turning itself on and off a lot, the screen has burnt it with my splashscreen.
The next thing I noticed is a spicy-pillowed/expanded battery.
Replaced that and now the problem seems to be gone. (still not sure which comes first : if the battery expanded because of the on/off OR the on/off is caused by the expanded battery)
My battery looks exactly like this (credit: u/SinisterCryptid)