The Apple Watch may be a powerful smartwatch, but it does not have an unlimited battery life. It is only natural to expect manufacturers to develop solar chargers or regular battery extenders for a device like this. The Reverse Strap happens to be such a solution. It is designed to extend the battery life of the Apple Watch by up to 125%. It has a magnetic inductive cradle to charge your device. The Reverse Strap has a 400 mA battery.