Hi guys, I have this lipo, its a thunder-power 7.4v, I dont have the balance plug for it, it has 4 wires for balance. My question is if I can convert it to a normal 3 wires 7.4v lipo balance lead.

you can buy an adapter, but if you want to make your own, the wiring on the Thunderpower is essentially the same as a pack with a JST connector. The extra red wire is just pack positive (if black is position 1, this wire is position 4). So just connect the first 3 wires from the battery.