A simple 2-pin connector soldered onto a breadboard-friendly breakout. This is compatible with the "JST PH 2-pin" connector. Mates perfectly with all Adafruit's 1-cell LiPoly and LiIon batteries as theyll as Adafruit's 6V coin cell holder and 3xAAA battery pack. Adafruit also have simple JST pigtails that mate with this connector.
You may get an off-white or black JST connector.