This is a fantastic product that lets you re-charge your batteries in the field with no mains power. Hook them up to any USB port that provides at least 600mAh – that includes most of them these days, including the MacBooks, or a USB power block like the example in the product images.
Charge in the car or even on a solar panel!
Has built in over-charge protection and cuts off automatically when the battery is charged.
Supplied with a USB Cable.