Back up Danger Sidekick ID battery is a much needed necessity and you do not want to be without power for your Danger Sidekick ID. A spare Danger Sidekick ID battery will ensure that you are always prepared. It can extend your talk time and reduce worry about dying Danger Sidekick ID battery life if you are on a long call or listening to music. It's also great for safety on long trips especially when your Danger Sidekick ID battery is dying and there is no charger around. A spare Danger Sidekick ID battery that is charged and ready to go will do the trick.