The algorithm of the indicator of the category of Dive Electronics L-3500
When there is only 2 LEDs - red and yellow, you must charge the battery. If You have not done so, the light force switches into power-saving mode, it will flash the 2 lower LEDs:
If You then are unable to get to charge, the light will switch into emergency mode "hard" energy savings while still flashing 1 red led, and the brightness will gradually decline:
Akkumulyatorniy to charge battery no need to open the canister. Charging is done using wet contacts. That eliminates the possibility of leakage at the connection.