Modern Alternaters don't charge?

Gday John

Pretty sure my alternator puts out 13.8v constantly, you may have a fault with your alternator or charging system.

Cheers Andrew

My battery voltage is 12,8 after standing overnight
Alternator voltage with engine running 14,3
This is certainly keeping the battery voltage more than just over 12 volts

I would not expect the tyre guys to advise you on alternators.

Most batteries sit at 12.3 to 12.5 volts when the engine is not running.

Sounds like he is guessing. Buy yourself a cheap $20.00 multimeter and test it yourself. You should have min 13.8 volts and max 14.8 volts. Ideal is around the 14.3 to 14.4 mark. Your Hi-lux looks quite new. Is it still under warranty.

What is drawing power from the battery ?

Do you have a dual battery ?

What isolator are you using ?

Regards Derek.

The bloke from Beaurepaires is a goose.

Generators got superceded 40 years ago, for good reason. Alternators put out between 14.1 and 14.4 volts because that is what a battery needs to charge.

From first hand experience I have seen a car with a flat battery jump started and two hours later it got sunk in a bog hole. That same battery then cranked the motor over for an eternity until it finally fired up. Being a start battery it accepted a heap of charge in a short time.

The slow charging of your aux battery may have something to do with the type of battery. If it is a basic deep cycle wet cell, I believe they only accept charge at a slow rate, I've heard as little as 5 amps/hour.

Still, there could be a problem with your alternator. Get a multi meter and check the voltage going into the battery; if it's under 14 I'd get it looked at. However I'm no Auto Elec and some professional advice may be needed.

Cheers,

Jim.

I agree with what Jimo said, Generators Do NOT charge at idle altenators do, mind you the last car i owned with a generator was an fc holden , my first car, had more ground clearance than some modern soft roaders
Cheers Pete

The charging voltage on alternators hasn't changed in the last 30 years.

Cars that are fitted with Calcium-calcium batteries will charge up to 14.8 volts.

Don't ask an Auto Electrician for advice about tyre problems, don't ask a Tyre dealer to do any more than bolt in a battery.

Go easy on the bloke, he was just trying to be helpful! Even if he is wrong!

At least it got me thinking a little more.

To highlight my ignorance a little more . . can someone point me at some instructions on how to use a mulitmetre to measure current draw? ie to find out what a radio / gadget / whatever is drawing from the battery?

Cheers,
John

You need to buy one that has a built in 10 or 20 amp test function.

Disconnect the battery positive and place the multimeter between the two.

If there is more than a 1/2 amp draw start pulling fuses and accessories till the draw drops.

Make sure you know where the multimeter fuse is and buy some spares.

Regards Derek.

Jimbo hi,
Off topic i know, But i get all nostagic about my fc. Owned in 69 70. Wish i still had it in a shed. Mate of mine just paid thousands for one with orinigal 70000m on it . Had chractor
Cheers Pete

If your dual battery set up is not right it will restrict the charge to the 2nd battery before it is fully charged, maybe get someone familiar with the piranha system to have a look at it.