www.trakpower.com/index.asp
Leads & Accessories link on left hand of page, you need one of these leads, a lot depends on the balance plug - must have a match to your balance/charging end, you may need an adapter for this. I think we all have trouble sorting this one....... balance plugs
If you look at the saddle pack's page the picture shows the link wire with the 2mm female socket for the 2mm battery balance wire, 4mm into pos & neg as normal.