What the car dealers don't tell you when buying a new Toyota Hybrid car, and the 12 Volt battery.

I must be one of the lucky ones. I had an Auris Hybrid for just over 7 years and not once did I have an issue with the 12v battery. When I traded the car in, it was still on it's original battery (in the boot).

Perhaps it was the way I drove the car as at the time I had quite a few long trips on a regular basis. Might lend credence to the theory of needing to drive the car a reasonable distance to keep the 12v topped up.

If that's the case then I need to get rid of my Hybrid and go back to ICE. If I had known that about self charging hybrids I'd never have bought one. A gripe I have with it too is not being able to use the radio with the car off, something I've always done in my ICE cars. I have to leave the car on while parked up to listen to the radio with the car engine randomly starting up and turing off as needed. I have to say it's a really poor design. I'd go full EV if I was able to get my own charger installed but can't due to management company policy.

This is a definitely design flaw. When upgrading a basic runaround car no one thinks about having to change their driving habits, they just want a newer car to do the exact same driving they had been doing without recurring battery drain.

I've tried to explain the problem repeatedly to the old dear with the Corolla but she can't understand it. She's right to assert that a new Toyota should just be as reliable as all the Toyotas she's had since the 80s.

It certainly puts me off ever considering one.

Don't get me started (no pun intended) on that Start/Stop nonsense.

It's the first thing I disable when I'm driving my wife's car.

Have a Toyota Hybrid 8 years since new. Still on the original battery and never an issue. Low mileage and plenty of short runs. Know a good few people who also have them and none have had battery issues.

Not really.

The 12V battery has no role in starting a Toyota hybrid, nor is it charged by an alternator.

The customer issue arises from the size of the battery, the programmed target state of charge specified by Toyota, and throttling of the DC-DC charger which limits the charge rate to such a level that a certain driving pattern is required in order to maintain the necessary charge level in the 12V battery.

Its not comparable to a traditional petrol or diesel engine battery charging arrangement.

Crazy really I have a 2012 avensis doing average mileage and only replaced the original battery 2 years ago.

The electronics failures can stop the car from starting.

Posted earlier on the thread:

A 2018 Yaris Hybrid failed to start with a flat battery only 2 months after purchase. The battery failure also effected the build in pre collision camera causing a software glith that made the car thing it was in a collision and would not allow the engine to start or even start in EV mode with the battery recharged.

I took the old lady's Corolla to a dealership to test the battery and they found no fault. They did admit that the newer cars required more driving than what was used to doing with all her previous Toyotas.

That information should be made known up front.