We use Molex/Waldom's 0.062" Standard 2-pin connectors, which are widely available from most major electronics parts distributors (Digikey, Arrow, TTI, etc.) and AMP/Tyco has a compatible series of connectors as well.
Part numbers used are as follows:
Connector Shell -- Molex/Waldom 03-06-2023
Pins (2 per connector) -- Molex/Waldom 02-06-2103
Battery, 6xAA Adapter
Connector Shell -- Molex/Waldom 03-06-1023
Pins (2 per connector) -- Molex/Waldom 02-06-1103
We offer enough parts for two of each connector, along with adhesive-lined heat shrink, in our "Connector Kit".