No need to use an external booster nor external regulator. Use the ESC's built-in regulator. This setup is the same as using a single 7.4v battery race pack to power everything. Many 12th scale racers have done this mod and have worked flawlessly for many many months. I have been using this mod for over 2 months now and no issues. Modify at your own risk and may/will probably void your Tekin warranty.