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Discussion Starter #1 (Edited)
Can someone check their battery voltages in accordance to mine...

I've been having electrical troubles (As if I'd switched the ignition key off and back on again when moving!) and after reading lots of threads it could be the battery. However, I've had it tested and it is supposed to be ok and the condition indicator light on the battery itself is also bright green, But....

Putting a voltmeter across the battery on a morning reads about 12.3V.
I've plugged a voltmeter into the cigarette lighter (12V power supply)

1. When I turn the ignition on (just to ON, not starting the engine) it goes down to 11.6 Volts for about 8 seconds (whilst all the engine checks are getting done ??)

2. Then it comes back up to about 12.3V

3. with the engine running it is a nice steady 14V (down to 13.7V with everything turned on)

The car starts on the first turn of the key so I really doubt the battery is bad, but 11.6V is not good!


Any ideas??
 

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Stop worrying! The voltage with the ignition on but the engine not running tells you nothing. The charging voltage seems OK. If you really want to test your bttery, you need a heavy discharge test which is what accessory shops and quick fit type places will probably do for free.
 

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After the pull from the heater plugs has finished? The rest of your observations appear as normal, so.... is the battery discharging, going flat with a permanent drain on it?:):
 

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Discussion Starter #5
Ah!! heater plugs. That explains a lot. Thanks.

I got the battery test done at the local motor factors and they said it was ok.

Just the volts always seem low, apart from when the engine is on.

I've read loads of threads/posts and a lot of problems have been cured by the battery so I'm going to try that first. It's already ordered and I'll be picking it up soon.

As for worrying, well, yes I am worried.
Losing all power when moving is not good, even worse if my wife is driving with the kids in it.
I mean power and everything.
Consider, at night,slowing down before/as you start turning to go round a corner..... and everything goes off!

You lose head lights, you lose the power steering, you lose braking performance (no engine) - YES, I am worried!
 

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had a similar experience with my 147 jtdm, It felt like you would be driving along and momentarily it felt like it had a hesitation through the car, it could be a cell in the battery failing, I changed my battery for a Halfords Calcuim replacement on Friday, cured the problem and all running fine.The Alfa needs a good battery as is the nature of its complex electrical system.Most batterys need replacement after 2-4 years
 

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Discussion Starter #8
That seems to be the case. I've bought a Bosch Silver series with lots of Oomph so I'll see how it goes and post up the outcome.

Cheers for the replies so far.
 

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Discussion Starter #9
Quick update..
Did a volt check on the old battery whilst still connected (key out of the ignition) = 12.3V

Disconnected it and it read 12.7V straight away??? so I wonder why?? ) 0.4V going somewhere??

Anyway, put the new one on and I'm getting another 0.2V above the old Alfa one so it is slightly better.

Just need to give it a week and see if the problem is still there or not.
 

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Posi lead disconnected. ammeter from battery post to lead, pull fuses if you have a massive drain? On the 147 we had, 36Ma. was suggested as about normal, although ours read about 46Ma I think.:): Clock, ECU, Blah, Blah.?:):
 

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All these voltages seem ok. However, in order to test alternator output, turn everything on and raise the engine speed to about 2000rpm- it should climb back up to about 14v (13.6v minumum).
 

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Discussion Starter #14
Yes,
No problem with the alternator, nice steady 13.8 - 14 Volts depending on the load.

I got an ampere check about a week ago and although I can't remember the figure I was told, it was a little high, but ok. If I remember from the table he had, it would last over 4 days before needing a recharge???

Fingers crossed that little bit more Voltage will keep the electronics happy.
 

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Discussion Starter #15
Update,
Same problem with the electrics so the old battery wasn't the problem.

No idea what the problem is now :confused:
 

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battery was sound as far as I could see from your voltage. Do you have mobile phone carkit ? they sometimes use power with contact off.
 

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Discussion Starter #17
No, no extras are fitted.

The car has always started fine, and really the battery was a hopeful grasp (of thin air).

Would a faulty immobiliser cut all the electrics?? including dashboard lights?
 

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What exactly is the problem?
 

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Discussion Starter #19
Every now and again. Tha car goes OFF

can't pin it down to any particular happening though.

so driving along merrily...... Everything goes off.. 1 or 2 seconds later everything comes back on again.

By OFF I mean it's like turning the ignition key off, all the lights go out (exterior and dash), radio goes off,...... and of course the engine stops so you lose power steering and brake boosting.

It's as if I had a loose battery connection/wire or loose wire on the ignition switch but I've checked them all and put extra Earth connections on. :confused: :confused: :confused:
 

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Check all major switches and relays especially underbonnet. I suppose you've checked battery connection. Check earth connections as well- especially battery and engine earth.

There is an igntion release relay, which interrupts power to every other circuit whilst cranking the starter motor. Check this, it's terminals and inside the cover for signs of burning.

I think you can forget about alternator and related things. It will be a wire, switch or relay.
 
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