Rechargeable vibrators carry a lithium cell and fill up from USB or a dock. You stop buying button batteries that die mid-scene and start remembering to plug the toy in after a shower, like a toothbrush.

Charge time and run time should be printed in real numbers. A toy that claims two hours and delivers twenty minutes on high is a familiar disappointment. Storage at full charge or at zero for months is hard on cells. Somewhere in the middle on a shelf is kinder.

Swollen batteries, heat, or a sweet chemical smell mean the toy is finished. Do not puncture the shell to investigate. Recycle electronics properly. Waterproof ratings assume intact seals; once a charge port cover tears, the rating is folklore.

Battery manners

• Unplug when full if the maker says to.
• Avoid cheap no-name cables that cook the port.
• If the toy is stored a season, wake it for a charge cycle.
• A travel lock saves the battery from an accidental on in a bag.