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[tunnie]

As per my other post, started the car again today, only just started... really was on its last legs. Gave it a 20 min run on Sunday.

Just went to reading and back .. about a 1 hour drive at 70+ 80+ on the return, went to uni picked up a grade and it started fine.

But when i got back and checked the battery (its a Vx Go) the little inspection thingy is black not green.

So the battery is buggered  

Its about 6 months old, but i think I have lost the receipt, however i bought it at the Battery at a dealer on TheBoys trade club card.

Can I just take it back to the same dealer and say its buggered give me a new one? They can go by the serial number?

[Kevin Wood]

Have you checked the voltage across the battery while it's running? Could be that it's just not charging well.

Kevin

[bigall]

My green dot disappeared from top of battery yesterday - battery 2 weeks old
started car ok and when running ignition light not on - so I thinks must be charging OK therefore knackered battery

While having new egr and O₂ sensor fitted this morning asked for test on alternator output
(via Tech2)  full load indicated battery voltage 12.4V LOW!!!!!! just about charging battery. Only slightly up on no load 12.8v. No ignition light showing either case.

Outcome - Alternator on the way out(only done 156K) To keep battery charging (slowly) run with low load til I can change it.

Old knackered battery was charged when I took it off 2 weeks ago  Today volts read 12.9
 Knackered my ar**.

Moral - don't condemn battery when it "fails" get an alternator output test as well.
            cost of new battery would equate to half of cost of replacement alternator alternator

[tunnie]

Cheers guys,

Unfortunetly no real time to test power at the moment (damn project in the way)

Not checked the output on the alternator, Vx Go batterys are usually very good so i suspect this could be my problem (mine has just done 100k)

When doing the cambelt James mentioned the alternator was loud...

Are 2.0 & 2.2 ones the same? Thinking of getting a scrappy one. Not sure how much they are from Vaux

[Kevin Wood]

Don't need a Tech2 either. A £5.99 multimeter across the battery is probably more accurate! Do make sure it's on the Volts range first though - NOT Amps!

I would follow this procedure:

Battery voltage - Engine stopped, rested battery, all loads turned off:

<12.5v - battery charge low
=12.5v - reasonable level of charge
>12.5v - fully charged

With a fully charged battery, headlights on for a minute or two. Voltage should drop maybe 0.2 volts and then stabilise. Should not steadily drop, certainly not below 12v otherwise battery dead.

Battery voltage - while cranking engine with a FULLY CHARGED battery:

<9v  - battery knackered (or occasionally excessive current draw from a bad starter motor)

Start engine. Run at fast idle (2000 RPM). Accessories off as far as possible.

<13.8v - alternator knackered
14 - 14.5v - Charging well
>15v - alternator knackered - DANGER - regulator giving too many volts.

Continue at fast idle. Switch on some loads (e.g. Headlights, wipers, heater fan).

<13v - alternator knackered

Before condemning anything, however, check all connections are secure, especially earth connections between chassis, battery -ve and engine block, block to alternator case and the charge cable from alternator B+ terminal to battery.

Measuring voltage between the alternator b+ terminal and alternator case and comparing with battery reading can sometimes highlight bad connections (voltage drop).

These voltages are a general guide (especially the running figures under load) and some cars show more variation than others. It depends on the resistance in the wiring loom and the alternator output. It's a good idea to make a note of what's "normal" for your car while it's in good condition so you can more easily identify when a problem has appeared.

Kevin

[bigall]

Im getting prices of £70ish for recon ones,

Original , in my case, is Bosch 0123505002  14V 100A

This ebay 160076530792   gives a listing of cars that the alternator fits - may be useful if you go scrappy hunting

[Kevin Wood]

You might find you can replace the brushes &/or the rectifier / regulator pack. It's bound to be one of those rather than the windings themselves.

Then again, once you've gone to the hassle of getting it off you might as well replace the whole thing I guess, especially as the bearings have been known to get noisy too.

70 quid is not too bad.

Who was it who had a bootfull of alternators at the cambelt party?

Kevin

[tunnie]

cheers Kevin again for that, think i am ashamed to saw never checked the alternator output on my car  

Did it to a project one some time ago, but never to mine!  

I have removed the Backup Alarm module on mine as it kept going beep beep beep, i suspect the alarm will go off if i leave the car for too long again. (say over a week)

Do you think its best to disconnect the battery? After this weekend I won't need to the car again for about 2 weeks.

I have limited tools here (i stupidly forgot to put them back after the cambelt party) I can get the negative supply off, but not the positive. Would it be ok just to remove the negative connector on the battery?

[Kevin Wood]

Just the negative off would be fine. at least that would prevent it losing any more charge, even if the alternator is the real issue.

I take it you're down at Brunel, in which case you're probably not too far from me if you want a hand & a multimeter (I work in Fleet).

Kevin

[tunnie]

Just the negative off would be fine. at least that would prevent it losing any more charge, even if the alternator is the real issue.

I take it you're down at Brunel, in which case you're probably not too far from me if you want a hand & a multimeter (I work in Fleet).

Kevin

Cheers Kevin, yeah might do that your just down the M3?

I need to do some more food shopping soon, then after that I won't need the car for a while. So might do that on Thursday, it should just start again hopefully.... do the shopping and then disconnect it when i get home.

However I might see what i am doing Saturday, be good to know if it is the alternator.

[Auto Addict]

My battery (9 months old) very rarely shows green, even after a long run.

Charging is spot on though.

[tunnie]

it a long run today over an hour, so i'll give it 2 days and see how it starts.

[The Barge Captain]

Mark DTM's guide to repairing alternators is quite useful.  Need to look at mine sometime (MID flickering) I was chatting to an auto electrician mate who recons that a new set of slip rings if needed cost about £8, brushes a couple of quid, and probably worth spending a tenner on new bearings whilst it is apart, so all told, might be worth getting yours overhauled rather than get a replacement.  Try a local independant auto electrician for a price mate.

[Kevin Wood]

Cheers Kevin, yeah might do that your just down the M3?

Yep. I work at Junction 4a but I could always trundle over after work on Thursday or meet you somewhere in-between.

might be worth getting yours overhauled rather than get a replacement

The downside to this is that the car's off the road for a while whereas an exchange unit only needs a few hours. Not a problem if the car is only used occasionally I guess.


Kevin

[Andy B]

.....
The downside to this is that the car's off the road for a while whereas an exchange unit only needs a few hours. Not a problem if the car is only used occasionally I guess.

The upside though is that if you get your own repaired you'll be dealing with a known quantity/alternator. I know it doesn't apply to all recon suppliers but ... you just get a set of brushes & a coat of paint at many.