The switch LED blinks 3 times, as does the main LED, then drops the main LEDs output.
In addition, while it’s in this low battery state (under 3.0V), every 8 seconds the switch LED alone should blink twice. So, these two events may interact and cause some confusion, depending on the battery state and the output level the user has set. The main purpose of the 8 second frequency is to show it when the light is turned OFF by the user and the cells are reading below 3.0V.
When the user turns off the main LED, the MCU is put into a deep sleep, low drain state after 5 seconds. But when the voltage is reading below 3.0V, it delays 6 minutes in order for the 2 switch LED blinks that happen every 8 seconds can be seen. It’s a way of telling/reminding the user - Hah! There’s a low voltage condition - check/replace your batteries.
Just fyi, every time LVP drops output, the voltage recovers partially, so if it recovers back over 3.0V and the draw is low, it might take a little while before the next drop, or the next drop could happen fairly quickly — all depends on the batteries, their level, and the level of amps/output.
Using flat tops or button tops? If using flat tops, could be not all making contact.
2.9? Ya…its gonna blink and shut off…
Even above 3.0…it might voltage sag under load and trip LVP. That is…the batteries are above 3.0…turn it on high…the voltage sags under load…light blinks…put in charger…could still be above 3.0.