How To Check Battery Condition

[R Gage]

What is the correct way to check for truck battery health, how many amp load for testing etc. or do you go to a dealer or parts shop and use their FREE testing offers? will they tell you the real condition of your battery or just try to sell you new one. thanks for any input

[dewfpo]

If you only have a voltmeter, wait 8 hrs after you last ran the vehicle and check for voltage. If it is 12.7V or better it is considered to be in good shape (all 6 cells making enough voltage). But that doesn't measure amperage output which is what you need to turn the starter motor. A load test is better because it measures the capacity of the battery instead of just the static voltage.

 

DEWFPO

[Matt427]

+1 on the load tester. I've seen plenty of bad batteries show 12-14 volts until you hit that load button, then they drop to almost nothing.

[Riverjet502]

Use A hydrometer if you don't have a seal battery to measure the specific gravity of each cell, this will tell you real quick if you have some bad cells...As mentioned above a battery can show good voltage but may not be able to carry a load due to dead cells.

[LeoS41280]

You can do a load test by putting your volt meter on the battery, then crank the starter. Watching the meter before the engine starts the voltage should not drop below about 10.5 volts.

[68haywagon]

The voltage only tells half of the story. I've seen a battery at my job holding 12.6 volts that only had 175cca. The battery was rated at 625cca. You need to have a load test done or have it tested with the newer electronic testers at the major auto stores.

 

Mike

[thearborbarber]

Good Idea

 

 

 

 

You can do a load test by putting your volt meter on the battery, then crank the starter. Watching the meter before the engine starts the voltage should not drop below about 10.5 volts.

[R Gage]

I found for sale a 50amp and a 100amp load tester.does anyone know which is the correct amp rating for GMC truck battery or none of them? or what should the amp rating be for testing. Thanks

[thearborbarber]

You want 50% of the Cranking Amp rating of the battery.