Back up i-Mate SP3i battery is a much needed necessity and you do not want to be without power for your i-Mate SP3i. A spare i-Mate SP3i battery will ensure that you are always prepared. It can extend your talk time and reduce worry about dying i-Mate SP3i 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 i-Mate SP3i battery is dying and there is no charger around. A spare i-Mate SP3i battery that is charged and ready to go will do the trick.