The battery recharges as all external batteries with a miscro usb port. When charging, a blue LED illuminates the USB jack.
The body is made of aluminum and some weight, all giving a solid feel. The LED type Cree, the latest generation is powerful.
PS: Remember to remove the present chip inside the battery for the lamp works (see doc paper), it's silly but I put 5 minutes before you think to read the doc, given the simplicity of the device.
A note that I have not encountered false contacts despite the manipulations. Something I had unfortunately often on small torches in recent years.
In the end, a small lamp / battery practice in car or handbag.