Altinator out put

[Tamora s6]

Hi does anyone know what volts I should be getting from altinator
On tick over am getting 11.5 v. Running getting 13 .5 I don't have any problems
With it but have got it on tricle charge. Thank 4 any help.

[gruffalo]

Sounds about right.

[Sevenman]

Tamora s6 said:

Hi does anyone know what volts I should be getting from altinator
On tick over am getting 11.5 v. Running getting 13 .5 I don't have any problems
With it but have got it on tricle charge. Thank 4 any help.

What is the difference between 'tick over' and runnng?

At idle / tickover, it should read ~ 13.5 volts.

When driving, it should read ~ 13.5 volts.

I would prefer to see 14, but my CTEK trickle charger provides topups and it all seems ok.

[gruffalo]

The gearing TVR used on the alternators does not really allow it to provide a charging voltage till around 1200RPM hence the low voltage at Rickover. At Rickover you have a reasonable drain on the battery hence the lower than 12 volt reading.

An alternator will only charge a battery to about 80-90% of full charge to ensure that the battery does not get over heated, this is why you see a higher voltage on a battery charger than you do from an alternator.

[EW486]

I was used to know that the alternator should get around 14,4 to 14,6V at all engine speeds, but the explanation about the gearing sounds reasonable to get lower volts at idle speed.
My old alternator brought exactly 14,4V at all engine speeds. Since it suddenly broke during engine rebuild it had max 13,5V and dropped to 7V when hot. So the battery got drained permanently.
My new one is at 14,6V at higher engine speeds and around 13,8V at idle speed.

You can also see here:
http://www.mytuscan.co.uk/faq_main.php#voltage