Many people want to use an 11.1V (3S) LiPo battery to replace a 7.4V (2S) LiPo battery to enhance the performance and response speed of their RC car. While this upgrade method is simple and straightforward, they may not realize that its feasibility depends on whether the ESC and motor support an 11.1V voltage. This requires you to check their product manuals or information on the products, as this is usually mentioned. It’s important to know that if they do not support it, overvoltage can cause the ESC or motor to burn out.
Additionally, when supported, what specific improvements can an 11.1V (3S) LiPo battery bring to an RC car? Next, let’s compare 2S and 3S LiPo batteries.
LiPo Voltage and Power
7.4v 2s LiPo Battery Discharge Curve (20A):
11.1v 3s LiPo Battery Discharge Curve (20A):
Based on actual test results, during the discharge period from a fully charged voltage of 4.2V to a minimum voltage of 3.3V, the voltage of an 11.1V (3S) LiPo battery is consistently higher than that of a 7.4V (2S) LiPo battery. This results in approximately a 35% increase in discharge power. For RC cars, this translates to improved acceleration, especially in scenarios requiring frequent speed and direction changes, providing a significantly enhanced remote control experience.
| Battery | 2S LiPo | 3s LiPo |
| Minimum Voltage | 6.6V | 9.9V |
| Nominal Voltage | 7.4V | 11.1V |
| Fully Charged Voltage | 8.4V | 12.6V |
Related Knowledge
Cutoff Voltage
For a 7.4V (2S) LiPo battery, it is recommended to set the cutoff voltage between 6.6V and 7V. For an 11.1V (3S) LiPo battery, the cutoff voltage should be set between 9.9V and 10.5V. This is important to know before running a 3S LiPo battery.
Power Depends on Voltage and Current
When upgrading from a 7.4V (2S) LiPo battery to an 11.1V (3S) LiPo battery, you also need to consider the battery’s discharge rate (C rating). This determines the continuous and burst current supplied to the motor. A higher discharge rate is always better.
Will Upgrading the Battery Increase the RC Car’s Top Speed?
Many people mistakenly believe that upgrading the battery will increase the RC car’s top speed. In reality, this is not always the case. The top speed of an RC car is determined by the maximum RPM of the motor, which is a fixed value. If the battery supplies more current than the motor requires, it won’t further increase the car’s top speed. In such cases, you may need to upgrade the motor, the associated ESC, and the gear ratio to improve the car’s performance and response speed.
