Every time we go on a long drive, my husband and I wonder if using cruise control while driving downhill saves us battery or other. Perhaps the very fact that we are using cruise control is using energy from the battery. So, does using cruise control while you drive conserve energy for your EV battery?
Yes. Using cruise control while driving downhill does save your EV battery energy. The reason is that to prevent the car from accelerating, the regenerative braking system is activated to maintain a constant speed. This system converts the car’s energy into electrical energy to recharge the battery, making it more efficient than simply coasting.
Having said that, let’s take a look at how cruise control affects your EV battery.
Overall cruise control can contribute to saving battery power. By allowing your vehicle to self-regulate its speed on the road, cruise control eliminates the need for constant acceleration and deceleration – therefore saving battery energy. This, however, only applies to flat roads or areas where traffic is light and the speed limit remains constant for a prolonged period.
Should You Use Cruise Control on Electric Cars While Driving Uphill to Save the Battery?
Not really. On hilly terrain, cruise control may consume more energy. This is because when driving on uphill roads, most drivers tend to ease up on the accelerator as they approach the top of the hill, anticipating gravity to aid them on the descent. In contrast, cruise control continues to keep the accelerator on longer than necessary, which results in increased energy usage. For optimal battery usage, it is advisable to use the cruise control only on relatively flat roads.
Should You Use Cruise Control on Electric Cars While Driving Downhill to Save the Battery?
When you activate cruise control on an electric car while traveling downhill, the car’s regenerative braking system will be used to maintain the same speed. Instead of allowing the car’s speed to increase, the system will recharge the battery, which is more efficient than coasting. It is worth noting, however, that allowing the car to slow down when climbing the hill and then picking up speed on the downhill slope is a more effective strategy than relying on regenerative braking, as the latter is not as efficient as coasting. Nonetheless, compared to conventional cars where friction brakes are necessary to control speed on downhill slopes, regenerative braking represents a significant improvement.
Without cruise control, the downhill speed can continue to increase without any limits if you allow it to. In this scenario, you may coast for a longer distance at the bottom of the slope before the speed drops below the desired speed. Although not using cruise control on a downgrade can save a bit more energy by extending the coasting distance, it is safer to let cruise control limit the maximum speed.
When driving an electric car using cruise control, the vehicle will maintain the set maximum speed, possibly charging the battery to hold the speed. If the battery reaches full capacity, the friction brakes will take over to maintain the desired speed.
When driving downhill, the primary concern is often not about energy conservation, but rather avoiding the car from gaining too much speed. In gas cars with conventional cruise control, the car simply disengages the accelerator, allowing the engine to act as a brake. Advanced cruise controls can also control the automatic transmission and shift down to improve braking performance.
However, if the car goes downhill for a long time and the battery becomes fully charged, regenerative braking will stop, and the standard brakes must be used.
What About Using Cruise Control in a Hybrid Car?
In a hybrid car, the system works similarly to an electric car when going downhill on cruise control. If the car speeds up, regenerative braking is engaged, and the excess energy is stored in the battery, which decelerates the car. However, since the battery in a hybrid car is much smaller than that of an electric car, it cannot store as much energy. If the battery becomes fully charged while driving downhill, the electric drive will begin to crank the IC engine without fuel, consuming electricity and slowing down the car.
In Conclusion
At the end of the day, if you look at it in depth, yes, driving in cruise control downhill can save some battery, but the differences are largely inconsequential. It also really depends on whether your downhill route is straight or has a sharp turn because driving a sharp turn with cruise control can be dangerous. Not only do you have to be mindful of turning the cruise control on and off, but if you are constantly busy activating and deactivating the cruise control is distracting and not particularly recommended.
I suggest you decide according to the conditions of the road and of course – according to your remaining battery range. If you are really on battery fumes – you should definitely use cruise control.
If the road has sharp turns and you have breathing space in terms of the battery, it is better to give it up.