economy mode comes on dash before car is started,C5 2008

[Stickyfinger]

I have mine flat on the dash pushed tight towards the passenger side screen pillar/screen bottom R corner. Wires run down via the pillar.

I reasoned that the more horizontal the better and it takes it off the screen, I kept hitting it when cleaning the inside of the screen and do not like it so close to a cold surface and then having hot demist air hitting it.

[Xantippa]

I think you can get more advantage if you clean battery terminals than by using that solar panel. In fact that´s what my garage told me to do. Those small toy solar panels give so little amps that they couldn´t even hold normal car battery´s charge, even if the battery wasn´t connected to a car.

[Stickyfinger]

Well the other one I have keeps my spare battery topped up via the office window...I know because I use it to power the C5 Leather electric seat at my desk

And I always rub Vaseline on my terminals ....I rub it in real good

[Xantippa]

OK. Now I understand your avatar much better.

I guess your spare battery is located inside?

[Stickyfinger]

Its is Sir, nice and snug with a pillow and a onesie.

[deano1970]

Hi everyone, C5 newbie here!

Got my 2009 C5 4 months ago and was always in economy mode before starting the car (from door unlock).
Looked at the battery and it was a Halfords battery, must have been a replacement so thought there should be some life in it. Cleaned the terminals and put some lithium grease on them and not had an issue since.
Hope that helps

Economy mode active is a feature on the C5 and nothing to do with a weak battery as stated on here before. The manual says on page 16 it is because many features still have power for up to an hour after engine switch off, like Windows, sunroof, mirrors, electric tail gate, wipers etc. This is all turned off after an hour so as to preserve battery power, doesn't mean your battery is weak