alt overcharge fried battery? help!!

[jmd2914]

I'm still battling my alternator overcharging issues and I'm curious if the alt over charging the battery could fry the battery and cause it to not hold a charge as well i.e. starting issues like if the battery were dead. im really stumped and can use all the help i can get.
thanks in advance

J

 

[jrichker]

Usually overcharging results in a battery that boils the electrolyte out and leaves you with exposed plates. Supposedly when air hits the plates, the exposed parts don't work as a battery after the exposure. This results in a battery with reduced capacity to start the car and keep the alternator working properly. Proper charge voltage is 13.8-14.2 volts at 72 degrees measured at the battery terminals. Cold days will cause the alternator to get up past 14.5 volts and not harm things.

 

[jmd2914]

so right now my car feels like its having charging issues ( battery not holding a charge) but the alt is working overtime ( overcharging) what would be the best way to go about this? take the alt and battery both down and have them tested?

 

[jrichker]

Most of the major auto parts stores like AutoZone or Advanced Auto Parts will test your charging system for free in the car. That's what I would do, since removing stuff to have it tested is a lot of extra work.

 

[jrichker]

Sorry, double post...

 

[jmd2914]

i yanked the alt an battery out and had them tested. Alt checked out, battery was good but they said it wasnt charging very well so they gave me a new one. so far it seems to be working, although my voltage is still a bit high. anything else i can check other than the voltage reg?

 

[HISSIN50]

If voltage seems high, have you checked actual output? Compare the reading at the charge stud (on the alt) vs the solenoid's battery lug.

Check the output stud vs the sense-circuit voltage. If the latter reads a good bit lower than voltage at the solenoid, this can cause the alt to send out a bit of extra juice.

 

[mustangsquared]

Sorry gotta bring her back to life...

where is the sense circuit voltage checked?? I had under hood smoke, electric fan stopped working and my battery is dry... so I figure its gotta be the alt...

 

[HISSIN50]

Sorry gotta bring her back to life...

where is the sense circuit voltage checked?? I had under hood smoke, electric fan stopped working and my battery is dry... so I figure its gotta be the alt...

It's the regulator wire labeled A.

 

[mustangsquared]

Thanks, get parts tomorrow and do some testing...