The Wipowerband is an Apple Watch external battery that claims it can double the battery life of the device. The accessory comes with a few caveats, including the fact that it was designed purely by "estimates". The Apple Watch is also charged on the back of the device using Apple's MagSafe charger. Apple will most likely need to approve of such accessories being released on the market.
Other than the fact that the accessory doesn't look too appealing, there will be more reliable companies out there creating similar accessories that we suggest you should wait for. However, if you're willing to take the risk, Wipowerband is available to pre-order for $89 for the 38mm case or $99 for the 42mm case in five different colors.
