Understanding your voltage levels is essential for maintaining “peak efficiency” throughout a one-hour race. Since you only have a limited energy budget, monitoring your battery’s state of charge ensures you don’t run out of power before the final lap.
1. Voltage Benchmarks #
For a standard 24V Lead-Acid system (two 12V batteries in series), use these benchmarks to gauge your “energy potential”:
- Static (No Load): A fully charged system should read over 26 Volts when the car is stationary.
- Nominal (Under Load): Once the race begins and the motor is drawing current, the voltage will typically drop to roughly 24 Volts.
- Operating Range: Expect a steady, predictable decline from 24 Volts down to 21 Volts.
2. The “Cliff”: Low Voltage Risks #
Dropping below 21 Volts is a critical warning sign for two reasons:
- Power Loss: You will experience a rapid loss of torque and top-end speed, often referred to as “falling off the curve.”
- Battery Damage: Discharging batteries below this threshold can cause permanent chemical damage, reducing their lifespan and capacity for future races.
Comparison: Gearing & Energy Consumption #
How you “alter your gearing to meet needs” directly impacts your battery voltage.
| Scenario | Impact on Voltage | Result |
| Geared Too High | Sharp, rapid voltage drops during starts or inclines. | Potential for early battery depletion and “rapid power loss.” |
| Optimal Gearing | Steady, gradual decline over the full 60 minutes. | Reaches ~21V just as you cross the finish line. |
| Geared Too Low | Voltage stays high throughout the race. | You finish the race with “tons of energy left over” and a slower average speed. |
Pro Tip: If your vehicle “rumbles or shakes” over potholes, it’s not just a mechanical issue—it’s “robbing your vehicle of precious energy” that could otherwise keep your voltage stable for longer.
