I have been using this type of flashlight for a year, and it is pretty easy to use. That's why I made this video to show you all.
This flashlight has 3 modes: very bright, normal light and flashing light. With this battery (20V 6Ah 120WAh), we can use 6 hours with very bright mode, 17 hours with normal light mode and 12 hours with flashing mode.

BOSCH 6.0 Ah 20V LiIon
Voltage 18V ~ 20V
Capacity 6Ah
10 cell of lithiumIon 18650

Lithiumion battery cell
Brand model: LG INR18650HG2
Standard capacity: 2800 3000mAh
Rated voltage: 3.6V
Charging voltage: 4.2±0.05V
Maximum continuous discharge current: 20A
Discharge cutoff voltage: 2.5V
Weight: Max.47.0g
Size: Max.18.2×65.2 mm
Charge and discharge times: 500 times

I hope you find this video useful and enjoy it!
Furthermore, I am happy to receive feedback, suggestions to improve myself.
!!! I'm sorry for the mistake if I did in this video !!!
Thank you very much for choosing to watch my video!
Have a nice day
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