TIP: If you want to replace the battery in an old Palm IIIc, replace it with a Battery from Cameron Sino which was originally designed for the Garmin iQue 3600! The connector
HQRP 884667201231162 Battery compatible with PalmOne Palm Pilot III / 3 / IIIc / 3c / IIIe / 3e / IIIx / 3x / VIIc / 170-0737 / IBM WorkPad 8602-20X
Palm Pilot Professional 3com Battery Replacement - iFixit Repair Guide