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Discussion Starter · #1 ·
Im going to use my multi meter to test my batteries. I just want to see the voltage on each battery. Is it ok to do this with both batteries hooked up? I think it would still show a bad battery even with them still hooked up. Im not sure if the amperage of both batteries being hooked up would cause a problem? I don't want to fry anything.
 

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Make sure DVM is on DC volts, and do each battery seperately. With both connected, you should read the same voltage on both batteries. With the B+ & B- removed from each, true voltage from each can be read. After disconnecting, give it about 15 minutes or so for the batteries to 'recover' if you opened your door(s), have a hood light, etc. Opening a door, having a light come on etc. will wake all modules and the TIPM, and can draw up to 3 - 4 amps when first activated (with nothing else on). I spent the last month troublshooting an electrical problem (bad stock audio amp), so if you need any help, feel free to PM me.
 

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if you want a true reading of the battery itself, then you should unhook it. but beware, the voltage can be deceiving, you can have 12 or so volts, but not enough amperage capability to run things for a decent length of time. your best bet is to get a load tester ( i think any auto parts place should have them) and disconnect the battery during the test.
 

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Im going to use my multi meter to test my batteries. I just want to see the voltage on each battery. Is it ok to do this with both batteries hooked up? I think it would still show a bad battery even with them still hooked up. Im not sure if the amperage of both batteries being hooked up would cause a problem? I don't want to fry anything.
You must disconnect the batteries before testing with a multimeter, else you're measuring the average of the two. Tells you nothing.

Having said that, you can't really test a battery with a multimeter. You need to go to Batteries Plus (or the like) and have them load tested. Load tester measures voltage with a good load applied. Load testers are usually computerized and have a good/bad threshold (must hold a certain voltage for a fixed amount of time like a minute, with a load of 100A or so on the battery). This must be done individually with the battery parallel cables disconnected, or you won't end up finding out which battery if any is bad.
 

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Discussion Starter · #5 ·
Thanks guys. Im going to buy the 4 dollar battery terminal puller cause the last time I tried to remove the cables a while back I couldn't get them to come off. The posts started flexing so I figured i would stop before I broke the seal. Someone told me I could use a flathead screw driver to spread the terminals and that was after the fact but I can still see imagine terminals flexing by doing that. I have a 130amp load tester. Im not sure if 130amps will do much good especially since it will only test for 15 seconds or it will overheat. Used it on a battery on a boat one time and it showed the battery was good even though it didn't have enough juice to fire the engine over.
 
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