What is the battery life of a Nintendo Switch?
The battery life for the Nintendo Switch is 2.5 to 6 hours
The Nintendo 3DS's battery life is described by Nintendo3DS.com below: "When playing Nintendo 3DS software about 3-5 hours. When playing Nintendo DS software about 5-8 hours. Battery duration differs depending on the brightness setting of the screen. The information regarding battery duration is a rough standard. It can be shorter depending on what functions of the Nintendo 3DS system are used."
Use the power switch or if that does not work, use the proper screwdriver , unscrew the screw that holds the battery, and remove the battery for at least 5 minutes, then put it back in. If your ds is under warranty do NOT remove the battery, instead try the power switch, or return it to your place of purchase to see if they can fix it.
the battery may be getting old or you somehow overcharged it and destroyed the battery, or you used it before you charged it when you first got it. If you use it before charging it when you first open it, you could severely shorten battery life. Not just for a DS or whatever Nintendo thing you mean, but for anything chargeable.
The Nintendo DS battery has been made to be recharged around 500 times, after which the battery life will be 70% of its maximum charge. The length at which a rechargeable battery will last depends on how frequently you charge it. For older devices, it is usually recommended to allow the battery to drain as much as possible before recharging.