I received some parts from Hobbyking yesterday for my micro rally wanted to share my experience..
1. HexTronik Balancer/Charger Dual Charge Capable
Seems very simple, just power it with a 12v supply, connect lipo via charging cord, wait for led to indicate charge.
2. ZIPPY Flightmax 180mAh 2S 15C
Fairly easy to squeeze into the stock battery slot, improved speed. Simple/cheap upgrade.
3. Rhino 360mAh 2S 7.4v 20C Lipoly Pack
Barely fits in the slot, not enough room to for the wires to fit, if you need the capacity and don't mind expanding the battery slot or trimming wires, this may work for you. I'm putting it aside for now.
4. JST Female 2 pin connector set (10pcs/set)
Replaced the stock connector on the vehicle with this. Cheaper vs going with losi micro connectors here and fewer changes. I may go to deans micro later because these jst plugs are rather large.
Took it out on the ice crusted back yard: