[jessestylex]

Whats the correct way to test the Battery with my Meter? the meter didnt come with instructions on how to test different things. i suspect my battery isnt holding a full charge and my wife said her car is acting strange also. im guessing the 90+ degree heat is playing a role in them. thanks.

 

[ostaF]

 

[bestatchess]

Remove battery from vehicle, connect to charger and fully charge, disconnect from charger and rest with open terminals for 12 hours.

State of charge can be estimated from open terminal voltage. Generally speaking, for 12V lead acid starter batteries, 12.65 and up after 12 hours rest is 100% charged.

Battery Tutorial

 

[Walrus]

You don't use a MM.
You use a load tester.
I bet you can buy a load tester for 12 bucks at HF tools.
Autozone, or pretty much any other nationwide parts store will load test it for free.

 

[VQP0WER]

walleeme is right. Multimeters will just tell you voltage, but not amperage. The battery could read 12-13v, but soon as you put a load on a weak battery, it will go down.