Battery voltage on a iAudio X5L

[rocksteady]

Hello everyone,

I use Rockbox on a iAudio X5L with success! Thanks for the great
piece of software!
The X5L use a Li-Ion battery. When the battery is full charged
I have a voltage of 4.17 Volts (Just perfect for a Li-Ion accumulator)
The thing is that the voltage graph is quite stable and then it falls
really fast down.
The minimum for a Li-Ion battery is 2.7-3.1 Volts. My question is:
Is there any Software-PlugIn that turns off the player automatic
when the Voltage reach 2.9-3.0 Volts?

Many thanks for any hints.