Battery Monitor - Revisited

After my initial try with the battery monitor, I wasn't too happy as it wasn't simple enough to use. The original circuit need to be switched on and off in order to avoid draining the battery.

Here comes version 2. The LED will only come on when the voltage drops below the set threshold. While connected to the battery in the 'LED OFF' state, the circuit will draw less than 1mA which is likely to be much lower than the LiPo self-discharging current... As such, the circuit can be connected to the battery indefinitely... the LED will only comes on if the voltage drops below the set threshold. The photo above show the old circuit and the new one (which is SMD).