Engine overcharging battery

[SJFH]

Hi,

Had my CHR 1.8 phev for about 6 months now. Up to a couple of weeks ago I was getting 50- 60% ev mode on my usual trips with 55-60 mpg. The engine cutting in keeping the Battery between 1/2 and 2/3rds charged.

I haven't been using the car much for that last month - maybe 2-3 short trips a week.

Then a couple of weeks ago, I started the car in ready mode and the engine cut in straight away with the Battery level about half. I drove off using engine power rather than the usual ev mode whilst the engine continued to charge the Battery to full - and kept going. I stopped the car and restarted it. I continued in ev mode until the battery level was about half and the engine kicked in again and charged to full!! It has been like this since then.

Checking my trip data, I am now using 20-30% in ev mode and my mpg had dropped to 25-35.

Thought I'd check here fro any insights before contacting the garage.

Cheers

[TonyHSD]

Hi, 

no need to contact the garage or worry about the car if you don’t have any warning on dashboard.
All as described it’s normal and typical behaviour for Toyota hybrids. 
The reason why the car behave like that is lack of use. 
The hybrid Battery has cells that needs to be conditioned, cell deviation equalised and for that reason the car needs the engine to charge and discharge the Battery numerous times until all cells get equal voltage.  
This is to extend Battery life and prevent premature failure of one or more cells. 
When the car does all that it is better practice to let it finish its job and then turn it off.  
Another time when the engine may remain ON for longer time is when you have low 12v battery.
The engine is the heart of these cars and the batteries are as additional help, power storage. 
 

[SJFH]

Thanks TonyHSD.

Thats  relief, I was worried that one of the hybrid Battery cells was about to go.

👍 🖖

[Gray86]

Wait until the cold winter days when ev Battery will be full, but engine is on to generate heat for the cabin 

[forkingabout]

I just leave the hybrid system to do it's own thing, I can't be bothered to look at the energy flow meter.

The hybrid system is much smarter then it's operator & it will soon flag up any faults which being a Toyota product is highly unlikely.