Low voltage output to battery - 13.3 volts

[Jamo]

I seem to be getting a low voltage to the battery, on a multimeter I'm only registering 13.3v

Any ideas on what the problem could be?

[mcandmar]

Charging current should be ~14v so it dosent seem that bad. The voltage regulator on the alternator do break down with age, in my experience they get a little below 13v before they die, and usually will only produce a charge over 2000rpms. i.e. you get the battery light on at idle. There cheap to replace and only held in with two screws. An old battery could also pull the voltage down.

What is the volt gauge in the car saying? I find they usually read a little lower than actual battery volts.

[Acidburn]

How longs the car been parked up and when was the battery fully charged up last, might just be due to sitting.

[Jamo]

Battery is fully charged athough even if it's flat you should see 14v across it because of the alternator output.

I may get a new 15v voltage regulator in that case.

[twoqu]

See if you get a better reading directly off the alterantor. Probably a large voltage drop through the cable back to the battery due to its length/age!

[Jamo]

Ah very true, I need to do something about it as with my afterrun mod the fan will come on after the coolant gets to 90c

[Jamo]

Forgot to add my battery is an Optima Yellow top

[s2_bo]

Optima yellow top kicks ***! They should last forever or there abouts.

I have a 15v regulator they are cheap enough and work well. There is a tread somewhere about them.

Good luck.

[Jamo]

Cheers Bo I found it late last night and order a 15v regulator

[macspring]

Jamo,

Would you be able to post a link to the thread ?

or to where you ordered the 15 volt regulator from ?

I presume a Becker radio will take 15v?

Thanks and kind regards.

[Jamo]

It's now the top sticky thread in the electrical section so it is easy to find

[Jamo]

Well the 15v was a 3B item, I now have a new 14v ABY to install.

Does this seem like the problem I get about 14v on the voltage gauge then as soon as the lights ( HID ) are switched on it's dropping to 12-13V?

I'm going to change the VR regardless as it's seen better days but it's hacking me off as sometimes have to jump the car, it's fine and then have to be jumped again days later

[Phil Payne]

I'm going to change the VR regardless as it's seen better days but it's hacking me off as sometimes have to jump the car, it's fine and then have to be jumped again days later

You probably don't need to change the VR - it's usually just the brushes and changing them is fairly trivial. Maplins do a nice text device for finding current drains - product code is N48CY. It plugs in place of the fuse and gives a direct reading - so you go down the fusebox.

The shortcut is to unplug the CD changer from the boot light circuit - that's often the cause.

[Jamo]

I haven't got a CD changer, never owned one.

[pixsaudisex2]

Take it your batterys in your volt meter are ok they start giving poor reading when they are flat.