C5 Battery Meter

mooseshaver · Post by **mooseshaver** » 22 May 2008, 12:06

I can't remember if I have asked this before or not, I couldn't find a similar post.
My C5 has a needle with a battery symbol. Whats it telling me. It has no numbers on it. Just red bits on both the left and right. Before starting, with the ignition on it is before 50% of the way. After starting it moves to after 50% and stays there.
Is it load? Or somehow battery voltage? Why does it not move around much?
Thanks

mooseshaver · Post by **mooseshaver** » 22 May 2008, 12:14

There is a picture of it here
http://www.mooseshaver.co.uk/meter.jpg

JohnD · Post by **JohnD** » 22 May 2008, 12:16

I read mine as a volt meter. Once the alternator works the needle maintains a more-or-less central position. I think my battery is on its way out, and when I first switch on, the needle tends to move to the left of centre. But bear in mind that the battery has done quite a bit of work before the engine starts with central locking and hydraulic pump levelling.

mooseshaver · Post by **mooseshaver** » 22 May 2008, 13:31

Thanks John.

Should a new battery be any different? Mine has probably not been changed in its 6 years of life. But no problems starting that I can see.

If its too far to the right, would that indicate overcharge from the alternator?

JohnD · Post by **JohnD** » 22 May 2008, 15:16

If the voltage of the battery was low, it would show on the meter. My C5 only gets used on our longer runs, therefore it stands idle for several days at a time. Even so, it shouldn't lose voltage so quickly. On one occasion recently, after it had stood for a week, I had to jump start it.
To check your own charging system I would put a meter across the terminals and see that you have around 14.5+/- with the engine running. I doubt whether the dashboard voltmeter is very accurate. Regarding the life of starter batteries - I've just replaced our 10 year old Saxo factory fitted battery.

Post by **myglaren** » 22 May 2008, 15:28

Might be best to take it for a load test, done by someone who has a clue how to read it.

I should take my own advice. Although all appears to be fine, never had any problems, I have no idea how old the battery is, could be the original one. Had the car 15 months and never looked at the battery. Tried to locate the AC yesterday when I filled the screenwash* up and gave up after a couple of minutes.
*only ever lift the bonnet to fill the screenwash. Not like the old days.

I'm inspired by my own post - I'll get right to it - maybe next week javascript:emoticon(':D')

steelcityuk · Post by **steelcityuk** » 23 May 2008, 16:04

It's mentioned in the handbook.

On starting mine registers just about half way then after starting goes slightly more than half way, which is normal. When George connected up his Proxia at Whetherby it actually gave a reading of 14.? volts.

I'd say that if the needle doesn't rise up the scale after starting the car the alternators on it's way out and if the needle is much under half way before starting the car the battery is being flattened whilst stood or is on it's way out.

Just my interpretation.

Steve.