Ideal companion for iPhone 4 & Co.

Recently, I have my iPhone 4 discovered as a companion for long bike rides.
GPS recording, listening to music and however Speedometer cost a lot of electricity.
After 3 hours, nothing works normally.

Application is therefore the continuous charging during the day, so as not to have to do without the technical support and at 8-12-hour tours.

The Gum Pro is ideally suited for this purpose. On the steering wheel I have a small mini pocket. There, the battery pack's inside. The cables I run outside to iPhone holder.
The iPhone can also be used while charging.

In addition to other reviews:

1. The iPhone 4 is loaded correctly and that relatively quickly! Much faster than the PC.
2. When charging, the Gum Pro is a red LED, which changes to a clear green after full charge lights.
3. The on / off switch must already be operated with significant force. Unintentional on / off, I can hardly imagine.
4. An additional cable is not required on the iPhone. All devices that can be connected with a cable to an available USB port, can be charged with the Gum Pro. The original Apple charging cable works fine at the Gum Pro.

All concerns (due to some reviews here) are scattered. Buy!