Although cars like the Toyota Prius can technically run on their internal combustion system even if the battery isn’t used to power the electric motor of the car, the performance, fuel economy and drive comfort will suffer a lot in the process. Moreover, no hybrid car can start with a battery that is completely depleted. Failing to replace a Toyota Prius battery at the right time can have dire consequences for your vehicle in the long run, even if the battery itself might not fully be depleted for a while (as, while it still works, it’s recharged continually by the engine or the regenerative breaking system).
You probably already know that a hybrid vehicle uses a combination of two different systems: an internal combustion system with a regular (though often weaker) car engine, and an electric system that uses an electric motor and a hybrid car battery. While the main battery is used to run the electric motor, a separate 12-Volt battery is used to power the car’s computer and accessories.
Unfortunately, the smaller battery can’t provide adequate power if the larger battery is completely dead. As a result, it is imperative that, when you notice your main battery failing, you contact a reliable mechanic to get your hybrid battery replacement done as soon as possible.