The science of behavior at the service of the environment
Plug-in hybrids act as a bridge between combustion engines and electric mobility, offering a path to lower emissions. But their ecological potential, like that of fully electric cars, only materializes if drivers recharge them consistently. The problem? Many owners don’t.
A plug-in hybrid that is not charged behaves like a standard hybrid, canceling out the benefits of its electric component. A study conducted by the Toyota Research Institute (TRI) found that the solution lies not only in technology but also in psychology.
ChargeMinder, the EV charging app built on psychology
Researchers from TRI’s Human-Centered Artificial Intelligence division developed an EV charging app called ChargeMinder. More than a reminder, the app leverages behavioral science to encourage drivers to recharge more often and at optimal times. Its strategies include:
- Timely reminders up to 50% more effective than generic notifications.
- Positive reinforcement through encouraging messages and progress visualization.
- Educational quizzes that use “memory science” to help users internalize better charging habits.
All interventions were personalized, using anonymous vehicle data and driver charging patterns while protecting privacy.
More charging, more satisfied drivers
The results from tests across 12 car brands were significant:
- In the United States, plug-in hybrid drivers increased their charging frequency by 10%. Vehicle satisfaction rose by 16 percentage points, reaching 100% among app users.
- In Japan, both PHEV and fully electric drivers shifted charging to hours with higher renewable energy availability, with daytime charging rising 59%. On average, this translated into nearly 30 extra minutes of charging per vehicle per day.
“Technology alone cannot cut emissions, people’s choices matter too. This research shows how behavioral science interventions can both reduce carbon emissions and increase customer satisfaction,” said Gill Pratt, Chief Scientist at Toyota Motor Corporation and CEO of TRI.
Why behavior matters in EV charging
For electric vehicles to deliver their full climate benefit, they must be charged regularly and, whenever possible, during periods of cleaner energy supply, such as when renewable power is available. Without a change in charging habits, EVs cannot fully realize their potential.
“Behavioral science is a powerful and scalable tool for achieving carbon neutrality,” added Dr. Laura Libby of TRI. Compared to large-scale efforts like new charging infrastructure or financial incentives, behavioral interventions are low-cost and can be implemented quickly.
How Toyota’s EV charging app works
ChargeMinder offers just-in-time reminders, motivational messages, progress streaks, and memory-based quizzes to make the act of charging less of a chore and more rewarding. The idea is to make charging feel less of a chore and more satisfying.