Strange Battery Charge/drain In The Heat

July 1, 2010

I had a strange one the last couple of days. It's been rather hot and driving round heavy traffic braking and crawling along, I've noticed that the Battery will almost get to the top (one bar from full) and then start doing strange things!

It won't allow you to select the EV option, will run normally but won't ever drain the Battery from the second to top bar however much you crawl in traffic on electric, yet won't allow it to fully charge if going down steep hills. It has also switched the engine on from time to time when in this state of almost full charge when stationary or crawling with the a/c on full blast. It's almost as if it is too hot but no warning lights are displayed.

I keep the cabin temp pretty cool at around 19c/20c and the Battery vent isn't blocked. Is this the sign of a failing HV battery or is it normal when it gets warm?

When I opened the hatch and felt above where the battery is housed it was quite warm to the touch. If I take the car out of town or pull over for a few mins the car returns to 'normal' and all is well again.

The above has happened twice in two days (outside temp 28c), surprisingly just after I got it back from the dealers when the attempted to fix my squeaky front seat.

Any ideas?

July 1, 2010

I had a strange one the last couple of days. It's been rather hot and driving round heavy traffic braking and crawling along, I've noticed that the battery will almost get to the top (one bar from full) and then start doing strange things!
It won't allow you to select the EV option, will run normally but won't ever drain the battery from the second to top bar however much you crawl in traffic on electric, yet won't allow it to fully charge if going down steep hills. It has also switched the engine on from time to time when in this state of almost full charge when stationary or crawling with the a/c on full blast. It's almost as if it is too hot but no warning lights are displayed.
I keep the cabin temp pretty cool at around 19c/20c and the battery vent isn't blocked. Is this the sign of a failing HV battery or is it normal when it gets warm?
When I opened the hatch and felt above where the battery is housed it was quite warm to the touch. If I take the car out of town or pull over for a few mins the car returns to 'normal' and all is well again.
The above has happened twice in two days (outside temp 28c), surprisingly just after I got it back from the dealers when the attempted to fix my squeaky front seat.
Any ideas?

GC,

Same used to happen with the gen2.

Something to do with the temperature of the Battery. i used to descend a very long hill starting with nearly empty Battery, was fully charged at the bottom but the ICE continued to run.

If you get the chance, turn off the power and then on again, the car will remain in electric forever (Well not quite, but you'll get nearly 2 miles)

I'd say its nothing to worry about.

.

July 1, 2010

Glad to hear that.

Off to the dealers on Monday to get the squeaky seat looked at (again) and have mentioned about the above carry on so will get them to double check the HV Battery whilst I'm in. I'm curious as to why it got hot when the inside temperature was 20c. I was working the car hard with lots of fairly heavy braking and then acceleration etc. I'm sure if there was a problem then a warning light would show, but equally I'd rather get it checked whilst I'm at the dealers.

I would say that my mpg is up quite nicely now that summer is here. I've just got my 6 monthly fuel bill at £1800 which is projected at £3,600 for the year. This is well down on the £6,800 last tax year when fuel costs were lower. So, despite some niggles I'm still more than happy with the car and the main dealers. :thumbsup: