I’ve been messing around with radio controlled car electronics for years now. I’ve managed to put high voltage battery packs in many of them without causing any damage. Though some of them have reacted unexpectedly.
Here are some of my findings and some advice on how you can increase the speed of your RC cars.
All hobby grade RC cars with have an ESC or electronic speed controller that plugs directly into the battery pack/s. This ESC will have an expected input voltage range. The ESC will be connected to the motor which will also have its own voltage range. The motor usually is able to take a higher voltage the the stated range but will sometimes run a lot hotter.
The ESC’s maximum voltage is usually dictated by the capacitors within the unit. But depending on how much higher voltage the battery pack/s is/are you may be able to just change it out and see what happens.
I’ve managed to run a 3s or 11.1v motor on 4s or 14.8v before with no problems at all, but this could cause damage to components over time. An increase from 3s to 4s produces a noticeable speed increase.
More Speed = More Fun