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Author Topic: Alternator Recommendations?  (Read 648 times)

Offline OllieVRS

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Alternator Recommendations?
« on: July 03, 2023, 11:03:18 am »
It seems like my alternator's been on its way out ever since I accidentally shorted it because I forget to disconnect the battery while taking it out for a thermostat job.

Running voltage is 13.7-14.2V depending on factors like RPM and lights etc. When car is turned off voltage eventually settles at 12.2V. Battery was replaced a year ago with a new OEM VW 72AH one.

All my voltage readings are taken from my Sony stereo.

Wondering wether to go for OEM, aftermarket or used?

Cheers  :smiley:
'06 Skoda Octavia vRS TFSI

Offline OllieVRS

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Re: Alternator Recommendations?
« Reply #1 on: July 05, 2023, 12:59:05 pm »
Measured battery with a volt meter after 4 hours of standing. It's at 12.3V.

Am I right in thinking that even with a weak alternator it should be able to charge a battery to 12.6V? Could the battery perhaps be at fault?
'06 Skoda Octavia vRS TFSI

Offline Octoparrot

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Re: Alternator Recommendations?
« Reply #2 on: July 05, 2023, 06:11:44 pm »
I'd say your battery is more likely at fault. A healthy charged battery should be over 12 volts. The running voltages seem ok to me.

Offline OllieVRS

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Re: Alternator Recommendations?
« Reply #3 on: July 07, 2023, 12:16:25 am »
I'd say your battery is more likely at fault. A healthy charged battery should be over 12 volts. The running voltages seem ok to me.

You're probably right. Took the battery out, using a halfords car battery charger, charged it for 6 hours. Voltage was a 12.5. Remeasured next morning, without anything even having have connected anything and it was at 12.2 again.

Phoned my VW dealer that I got the battery from last year about a warranty. Said he'll put in a request with the Skoda dealer as I have a Skoda, and it's up to them to honour the warranty (???). Despite me buying the battery from the VW parts department at the dealership  :thinking:. But on a positive note he said that if Skoda doesn't honour it, he's personally ordered in a replacement battery that he can give me that will arrive Monday, a.k.a being shipped in from the UK as they don't have any on hand.

'06 Skoda Octavia vRS TFSI

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Re: Alternator Recommendations?
« Reply #4 on: July 07, 2023, 08:46:03 pm »
I'd say your battery is more likely at fault. A healthy charged battery should be over 12 volts. The running voltages seem ok to me.

Agreed.  I wouldn't be wasting money on an alternator based on those engine running voltages.

A new battery holds 12.6V for days.  If it's dropping to 12.2 over night, it's got a bad cell or 2. It is more likely that didn't like the short circuit over the alternator.


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