2001 Prius Energy Monitor screen battery symbol

Hello all, my first post and it is a strange problem.

My 2001 Gen 1 Prius has been faultless until a few weeks back when the battery on the energy monitor screen charges and just seems to keep charging. The green rises above the '-' (minus) '+' (plus) at the top of the battery on the right. I also notice when the battery is full (overfull as I call it) the car doesn't decelerate too well. What I mean it seems to accelerate even when I am off the gas.

If I stop and switch the car off it corrects itself, but the battery on the right rarely goes to half way down, it always stays full. The car does switch off when motionless once I have righted it. No other warning signs are present, and it is otherwise faultless with just 80,000 miles now.

Sorry for not explaining it very well and not using the correct terminology, and I am useless with computers, so hopefully the following picture will work. It's the battery (minus and plus) on the right of the screen that fills up to the point that the minus and plus symbols are not visible.

EDIT, seems I am not allowed to post a picture, but I hope you know what I mean.

Any ideas? I hope it's nowt too big as I love the car. I have a another small problem too, but shall save that if the outcome of this is not too bad.

Many thanks.
Mark.

 

Thank you bisco for the info and welcome.

That is not what I wanted to hear. There are not a lot of parts available in the UK, and even less experts who know how to work on them. For example some high street places won't even replace tyres.

I should have said earlier, that it's booked in to a Toyota dealer for a service in two weeks (at no small cost) and apparently they give all Prius cars a free hybrid check. I am dreading the results now.

Thank you again.

 

..............

 

Thank you Brian.

Hoping it's not the battery pack, as the cost of replacing it is more than the car is worth. I can get a Gen 2 Prius for less. There is no network in the UK for the Gen 1 Prius besides the main dealer. I had to replace the rear light cluster last year and it took me ages to source.

Anyway, I drove it for 60 odd miles today and it behaved itself perfectly, so maybe it's intermittent.

It's such a lovely car to drive that I am hesitant to change it as I know the history and have become attached to it.

I shall see what the dealer says next week, and even then I shall just keep driving it I think. 80,000 miles is relatively low miles on a Prius - so hoping it's okay for a few more yet.

Much obliged for your help - thank you.

 

An update or sorts.

Today I took my Gen 1 for a full Toyota service, and a diagnostics check on the batteries.

Everything came back as it should, and the car was given a full bill of health. No advisories on the MOT, nothing.

So it shall remain a mystery I guess. It has not happened in the past two weeks.

Had to laugh. Whilst I was sitting in the dealership waiting for my car to be valeted I was approached by a Toyota employee enquiring if I would be interested in selling my car to him. He offered well over what it's worth, but I had to decline. I have looked after the old girl for many years, and she may be 16 years old but looks like a new car. I intend taking her on a trip around Europe this summer.

Thanks again for all your help guys, and happy motoring.