Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

ur battery is getting over charged if it reads 15.x + volts with engine running.
The regulator which built into the alternator would be the cause, just take it off and have it checked out for FREE at autozone and stop guessing.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

My battery is being drained when it is sitting as well. I can drive the car for a while and disconnect the battery and when i come out itll start up just fine, shhowing me that the battery is being charged

LEave it connected and the voltage on the battery starts to drop, i cant figure out how to find out how much, I have a 2 prong multimter but on every setting I use I either get an error reading or something complrely different that 50 milli amps. I dont even know what sign to put it on to get a milliamp reading

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

If it has a SHORTED cell it will drain itself over time!!! THINK about it. If you take a AA battery with a piece of wire and a resistor, and connect the 2 ends, it will be similar to a shorted battery seeing as the resitor would be a 'shorted cell' similar as to your car battery. Now, connect a bulb to it also with the resitor connected still in paralell circuit to it, and it will light up ok (bulb is load of engine trying to start). Leave the resitor on, but remove the bulb, wait 1 hr, try the bulb again, doesnt light does it? (like trying to start your car again) It just drained itself from its own shorted cell. Think about it real slow, its not that hard. Get a new battery, replace the alternator, and it will be 100% again. If dont want to take anyones advice, dont ask.

Re: 2 Batteries NOT Charging - Alt Is New/ Battery new- Car Runs With Terminal Disco
 

dude just for the record u r not sposed to run ur car with either of the battery cables disconnected..ur battery acts like a buffer for any surges of power that ur car shoots out...also if u still want to check if ur alternator is bad then get a multimeter and put it on AC voltage...then while the car is running stick it on the two terminals and if it reads more then .5v in AC then that would mean that your diods in ur alternator are shot and its letting voltage back the other way and causing a draw on ur battery...also try cable to post voltage drops...see if u have any resistance in ur connections