I bought the dual batt wire from them and I use 2 6 cell nmih 4200 mah and it fried my esc it took off then started smoking when u called and asked why they would only give me a replacement at 10% off and not warranty replace the part so I bought a better one be careful with the stock one with stock stick to one batt with high mah for better run time but with the two batts it did take off like a bat out of Hell