You can check the battery level You can put up to 3 batteries, and charge them in order from high to low. Batteries with high power are first. Support PD, QC3.0 fast charging The MINI 3 battery can be converted into a power bank to charge the remote control or other USB devices. It can also store batteries for easy portability. Input: 5V/9V/12V--3A (max) Output: 8.5V==4.0A(max) USB output: 5V/2A Charging time: (input: PD 40W or higher) 2453mAh battery about 90 minutes (45 minutes per battery) 3850mAh long battery life about 130 minutes (65 minutes per battery) Colour:As Shown Material:plastic Package Contents: 1 x 3-Way Butler 1 x USB-A to USB-C Charging Cable 1 x USB-C to USB-C Charging Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.