Question on batteries, how to test them

[84cucv1ton]

its a m1008. with his set up he needs 4 batteries. he got some older red top optimas for a pretty good price. checked them with a meter. said all 4 12v. all 4 are new. few years old. his truck doesnt even crank over. says 12v. never been used??

missing something. ideas? thanks

 

[Sephirothq]

Did you use a load meter or just a volt meter? you really need to use a load meter to determine how strong a battery is.

 

[84cucv1ton]

volt meter is what i used. anyway to test with out load meter? dont have one here

 

[Michael]

If they are in the truck you can turn the headlights on.

 

[Ken_86gt]

If you test the voltage while the key is turned, while trying to start, and it still says 12V- then you have a problem other than the battery. It is normal for the voltage to drop some while cranking, but if you see it drop close to 0V then it is likely that the batteries have issues. As stated above you could use a load meter- take the batteries to your locals parts store and ask them to test them, they should not charge you anything.

 

[Michael]

I have never seen a M1008 with four batteries. How does he have them wired up?

 

[Crash_AF]

Without a load tester, put your leads across the battery while he's trying to crank it. If it drops below 9V while cranking it is probably bad. Optimas have a real bad problem with being discharged and recharged too many times, causing the plates to sulfate and the battery to lose capacity quickly. If your friend has access to a desulfating battery charger, try to run it through a desulfate cycle and see if that helps.

Oh yea, yes it is possible for a battery to have 12V and still be bad. The true test is the available cranking amps.

Later,
Joe

 

[papercu]

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Prestolite / Indiel / Leece-Neville Alternators and Starter Motors

 

[84cucv1ton]

thanks