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View Full Version : I just keep learnin'


gmrulz4u
10-11-2002, 04:43 PM
I've been looking for a lot of stuff online regarding GM alternators, and happened to find something interesting...

The CS-130, which is what all of our cars have, something that causes them to STOP charging the battery if the voltage goes below 12 volts!?

"The CS-130 alternator's voltage regulator has what is called "Low Voltage" protection. This means that the voltage regulator looks at the state of charge of the vehicle's battery and if that charge is 12 volts or less, it will not allow the alternator to turn on. This protects the alternator from working too hard to charge a low battery. After all, the alternator is not designed to be a battery charger. This is why so many people think they are getting alternators that are bad when in fact there is nothing wrong with them except for the fact that the vehicles battery was discharged, or there was a voltage drop between the battery and alternator due to bad connections or deteriorated cables."

I don't think this seems right??
Brian P
10-13-2002, 12:43 AM
I think not! When the alternator dies, it's because it's a POS!
GnatGoSplat
10-13-2002, 01:38 AM
That makes no sense to me. The alternator IS a battery charger!
If it weren't, then how would one explain how if a battery gets drained, jumpstarting it can bring the car alive again and recharge the battery!
crc
10-15-2002, 02:00 AM
I don't think this seems right??

Makes sense actually since the Alternator is not designed to fully recharge a battery. Yes, it can certainly recharge a battery but whatever recharging it's suppoed to do happens on the top end. If the voltage on your battery is constantly well bellow 12v (or some other threshold) than there is no quicker way of damaging the Alternator than to let it try to fully recharge a dying battery, that is why the electronic circuitry is present to initiate voltage cutoff. If you replace your Alternator and/or Battery, always check the charge of the battery. A new battery should be fully charged before it is put in (charged on an off-vehicle charger). Even if you are only replacing your Alternator you should have a fully charged healthy battery in there. The two are like siamese twins, if one goes bad both suffer.