2150 second battery?

[psone]

Is it possible to just plug in a second Li-Ion battery inside the 2150?  I see the connectors and a spot for it.  My current battery is not holding much of a charge after two years.

[RobotLady]

Yes, but I am not sure if it's a good idea to leave the failing battery in there with it.  Run it down until it no longer works for you, then replace it with a new one.