Powertraveller Powermonkey Discovery
Planning an all-day ride and worried your phone's battery will give up before you get to that final Strava segment? A battery-pack charger like the Powertraveller Powermonkey Discovery could be the solution.
Powertraveller is a British company which makes a very wide range of recharging solutions with onboard batteries. They have products to top up your phone as well as rather larger offerings to get your laptop or even your boat going.