C5 Battery Deficiency

cachaciero · Unread post by **cachaciero** » 05 Jul 2011, 16:43

Well there i was two hours from home fading light and "bing!" and a warning message which I hadn't seen before "Battery Deficiency"
Well a quick mental inventory left me feeling sure that I had a battery before staring out so maybe it was trying to tell me that more was coming out than was going in.
So thought I "well should last a couple of hours on the battery" I mean the XM would have no problem going three or four hours on a fully charged battery
Then the horrible truth struck home this was an electric everything car and the drain on the battery was going to be way more than the XM and whats more I didn't have a clue of just how many amps was being consumed.
After a bit of mental calculation based upon guestimates I came to the conclusion that I was going to be lucky to get home before it died. There followed an exercise of switching everything off that I could but cabin fan and radio wasn't going to do much to stop the drain

.
Then the warning went out

SInce then it has come back briefly but once so from this I have a few questions.

Does anybody know just what the total current draw of an HDi is?
Assuming the message means what I think it does then it would suggest that the alternator is on its way out presumably brushes.
Is brush failure a common failure at around the 100K mark?
Are brushes available? if so where from? Can I change the brushes without removing the alternator?

cachaciero

Unread post by **Peter.N.** » 05 Jul 2011, 18:50

Hi Cachaciero

The actual electronics don't use much power its motors and headlights that do. It could be that the alternator output is low, connect a voltmeter across the battery with the engine running, you should have about 14.4 volts, much less and either the regulator is faulty or the belt is slipping, around 12 volts and its not charging at all. In 15 years of running XMs I have never had an alternator fail - but of course yours is modern

Peter

Unread post by **RichardW** » 05 Jul 2011, 20:55

If it's a Bosch injection then it will have an electric in tank lift pump. This is pretty hefty and pulls somewhere like 20A - the battery on its own won't last long! POssibly the alternator had a blip, or the battery is going duff - low voltage on multiplex cars can cause all sorts of mayhem!

cachaciero · Unread post by **cachaciero** » 06 Jul 2011, 13:09

Yes it is Bosch, 20Amp for the Lift pump, the suspension pump takes another 20/40 when it runs so lets average that out as a 2 Amps If I allow 0.5 Amps for each computer thats 12 amps. So 40 Amps would seem to be a reasonable estimate.
So about the Max time one could expect from a good fully charged battery would be about one and a half hours tops and practically probably closer to one hour. Probably half that if lights are needed.

Food for thought indeed

cachaciero

Unread post by **daviemck2006** » 06 Jul 2011, 14:38

My alternator went just before 100k. It came up with all sorts of messages and battery gauge was swinging about from side to side randomly. Got me home nearly 50 miles in the dark and a blizzard. Called out AA next day, they diagnosed alternator, was quoted something ridiculous like £650 from citroen stealer for exchange reconditioned one, got one from alternatormart.com, think it was about £150 delivered, got new belt as well about £10 and was quite an easy fit, just enough room to revove without dismantling anything else. Still have the broken one, keep meaning to get it fixed just in case.

cachaciero · Unread post by **cachaciero** » 06 Jul 2011, 20:14

daviemck2006 wrote:My alternator went just before 100k. It came up with all sorts of messages and battery gauge was swinging about from side to side randomly. Got me home nearly 50 miles in the dark and a blizzard. .

Can you remember what the 50 miles was in terms of time?

cachaciero

Kowalski · Unread post by **Kowalski** » 06 Jul 2011, 21:57

The post facelift C5s have electro-hydraulic power steering, that'll consume a fair amount of current. There is also the suspension pump although that won't operate very often.

Unread post by **daviemck2006** » 07 Jul 2011, 19:51

cachaciero wrote:
daviemck2006 wrote:My alternator went just before 100k. It came up with all sorts of messages and battery gauge was swinging about from side to side randomly. Got me home nearly 50 miles in the dark and a blizzard. .
Can you remember what the 50 miles was in terms of time?

cachaciero

Normally takes just over an hour to get home would probably been a little bit longer in the snow, maybe as much as 1 & 1/2 hrs. Car did start next morning, just. Just looked up, new alternator was £117 plus delivery, that was not exchange, kept the old one, the delivery was prompt as well.

cachaciero · Unread post by **cachaciero** » 07 Jul 2011, 22:48

daviemck2006 wrote:
cachaciero wrote:
daviemck2006 wrote:My alternator went just before 100k. It came up with all sorts of messages and battery gauge was swinging about from side to side randomly. Got me home nearly 50 miles in the dark and a blizzard. .
Can you remember what the 50 miles was in terms of time?

cachaciero
Normally takes just over an hour to get home would probably been a little bit longer in the snow, maybe as much as 1 & 1/2 hrs. Car did start next morning, just. Just looked up, new alternator was £117 plus delivery, that was not exchange, kept the old one, the delivery was prompt as well.

Ah! that was what I figured it might be given the conditions

.
That did better than I expected then, so with a good battery and a little luck an hour and a half is do-able with headlights, that's worth knowing.

cachaciero