One thing to keep an eye out for is... old laptops. The battery in a 10-yr old laptop will start expanding eventually. If it starts doing that, then carefully take the battery out before it starts to bend the MB or other parts.

They say don't use your phone while it's charging. That's because the phone's battery wasn't designed to handle the heat from both, charging and having an intensive task running at the same time.

Hope this helps.