The low battery indicator doesn't work particularly well with recharchables.
With a standard non rechargeable alkaline the voltage drops gradually as the battery discharges, so the battery light coming on at a certain voltage gives the user enough time to save their game and replace the batteries.
Rechargeable AA batteries have a much flatter voltage curve - they basically give a stable 1.2V until they run out of juice and then drop rapidly.
With a standard non rechargeable alkaline the voltage drops gradually as the battery discharges, so the battery light coming on at a certain voltage gives the user enough time to save their game and replace the batteries.
Rechargeable AA batteries have a much flatter voltage curve - they basically give a stable 1.2V until they run out of juice and then drop rapidly.
Edit: not lithium, Ni-MH