Miller ML-101 V6.0 is an extremely tiny 18650 charger. It needs an external USB power to charge. Remember, can only charge one battery at a time.

Mini Single Cell Battery Charger:
Tiny battery charger for flat top 18650 batteries (65mm length)
With a micro USB interface
Compatible with universal micro USB cables of Android phone
With LED indicators
Red when charging and green after charged
Reverse polarity protection / short circuit protection
Prevents damage from incorrect insertion. The LED indicator shows both green and flashing red light simultaneously when a battery is reverse

Notes:
● Input: DC 5V 2A (recommended)
● Charge accuracy: (4.2 ± 1pct) V
● Charge current: 1.3A
● Charge time: 3 - 4h (based on 2600mAh - 3400mAh battery)

Warm prompt: The battery is not included!!