My garage has told me my alternator is producing too high a voltage and over chargeing my battery "cooking it".
How is this possible - I don't know much about cars, but I know a bit of physics. Any ideas Anyone >
2007-03-02 03:47:26 · 15 answers · asked by mot 1 in Cars & Transportation ➔ Maintenance & Repairs
The alternator provides anywhere from about 14v to 17v typically - which, when applied to a battery that needs some charge, is "pulled down" a little anyway - to around 13.8 - 14v. As the battery comes upt to charge, however, if the regulator does not kick in, the alternator, keeps providing around 15-16v typically which does indeed start to boil off the electrolyte.
It will also make filament bulbs die a GREAT deal sooner - though you probably have lovely bright headlights at the moment.
Sounds like you need a new regualtor - or if built into the alternator - a new / recon alternator.
sorry, he may well be telling you the truth.
Pop a voltmeter on your battery after a long drive and with enginr running. If you see a voltage higher than 13.8, he is being honest with you.
Above 15v and you might want to switch off any expesive ICE - they may well have capacitors only rated at 16v - and you might well be pushing them to destruction.
Mark
2007-03-02 03:53:35 · answer #1 · answered by Mark T 6 · 3⤊ 0⤋
There's a vital component on all alternators called a "voltage regulator". It sort-of works like a dimmer switch for room lighting.
The alternator makes a constant output of around 16-18 volts of DC, which it sends to the voltage regulator to administer to the system as-needed. If your battery is fully charged, the voltage regulator allows a minimal amount of power to pass through to the system [your car's wiring, battery, etc]. Under a full-load condition [headlights, wipers, ventilation system blasting, etc], the voltage regulator will allow a maximum of around 13.8 volts to flow towards the battery, keeping everything in-check.
If the VR fails in its duties, it will either "stick" at the 13.8 level, and you may not for years know your VR has died, or it can stick at a lower level and your battery will always seem low. Also, the VR can go wide-open and allow all +/- 17volts out into the system, essentially "cooking" your battery as the acid within starts to boil and escape out of the vents in the battery. In some cases, this high voltage can also harm electronic components in the car.
On most all cars of the last 20 years, the VR is built-in to the alternator and not typically replaceable, at least not easily. Specialty shops can replaced that component for you, but its costs usually outweighs any benefit. In my experience, it's best to just replace the worn alternator with a new or remanufactured one that has a warranty.
Good luck~
2007-03-02 12:02:57 · answer #2 · answered by gtimandan 2 · 1⤊ 0⤋
As you know a bit about physics then this will be easy for you. The alternator generates an A.C. voltage. This passes into a diode pack (bridge rectifier) where it is half-wave rectified. The battery (having BIG internal plates) acts as a massive smoothing capacitor. The only way to cook a battery is if one or more of the diodes in the rectifier has packed up, causing A.C. to be generated. This unrectified A.C. voltage passes into the battery causing it to bubble / not charge / cook. Although it does clean the plates nicely!
I hope that this information is useful to you.
If I was you I would buy a diode pack from a retailer and fit it myself. They are only a plug-in device on the back of the alternator.
2007-03-02 12:01:46 · answer #3 · answered by ? 3 · 2⤊ 0⤋
the alternator will put out all the voltage and ampers that the car requires and that is controled by the regulator, so that is where the problem lies and that is mounted inside of the alternator .that also can be replaced when you take the alternator apart..if you have no nohow get someone that has the experiance ..you can get the insulating washers in the wrong place and that will not let the alternater do its job..good luck
2007-03-02 12:01:19 · answer #4 · answered by sparkey 1 · 0⤊ 0⤋
There's a control box on the alternator that regulates its output. If this is defective then the full output of the alternator is applied to the battery and fries it. Unfortunately the control box is an integral part of the alternator in most cases and means broken control box=new alternator.
2007-03-02 11:53:03 · answer #5 · answered by Del Piero 10 7 · 3⤊ 0⤋
Yes, I think this is possible, I believe that the alternator has a regulator on it to control the level of power that it pumps into the battery, if that regulator goes the amount of power going into the battery can overcook it.
2007-03-02 11:56:50 · answer #6 · answered by Anonymous · 1⤊ 0⤋
The regulator, sometimes called a diode board has got damaged, sorry you will have to change the alternator, as the regulator is a part of it, you may be able to get an " exchange" one that is you put your old one in part X for a new or reconditioned one.
2007-03-02 12:02:29 · answer #7 · answered by ? 6 · 1⤊ 0⤋
your voltage regulator inside the alternator is bad. Actually some are internal some external. You can buy the part yourself.
2007-03-02 13:58:23 · answer #8 · answered by Chawk 2 · 1⤊ 0⤋
Don't think they know physics though. Did you take it to a cafe? (cooking it), Try replacing the regulator, It proves alternator works so its not being limited.
2007-03-02 11:56:19 · answer #9 · answered by mikey_mossom 2 · 0⤊ 0⤋
The settings or something is out of wack as when the battery is full its not suppose to charge any more or lessen the charge.
2007-03-02 13:05:43 · answer #10 · answered by Scott 6 · 0⤊ 1⤋