Battery Testing

[crobar]

What kind of testing beyond a basic voltmeter test is needed to verify the true condition of a 12V vehicle lead/acid battery? At gas stations I see them using the bulb type of tester where they sample each cell looking for ?? I've also heard of a load tester. Is there one test device that will give you the overall condition of the battery?

 

[Silvertip]

Re: Battery Testing

There are two ways to test a battery. 1) A load test. This amounts to a large carbon pile or resistive load applied directly across the battery terminals which tests the ability of the battery to deliver the amperage stated on the label. 2) A hydrometer tests the specific gravity of the electrolyte in the battery. While that test indicates relative battery condition (as in state of charge) it is not as good a test a load test. Do not waste your money on the so called "battery gauges" or "battery condition" gauges. These are nothing more than voltmeters calibrated as Good-Marginal-Bad. They do not represent battery condition. They simply represent battery voltage in using another term. A battery that is incapable of delivering its rated current may still measure 12 volts but be a worthless hulk in your boat.

 

[ziggy]

Re: Battery Testing

if you have a napa by you, perhaps they can help you out.
i took my batt. over to them and they did a load test on it for free. i also did the specific gravity test with one of them cheapo testers from the auto parts stores. so i did both test that silvertip is talking about. i got a clean bill of health back from boat tests and feel my batt. is likely to last the season..

 

[crobar]

Re: Battery Testing

I don't believe I have ever seen a battery load tester. Is this an expensive item? How often would you use a load tester for batteries that are being used to drive an electric bow mount motor?

 

[ebry710]

Re: Battery Testing

At Harbor Freight their not.

 

[dan t.]

Re: Battery Testing

cheep hand held load testers are like polititians,nothing they say can be believed, take your battery to a shop that has a carbon pile load tester,only then will you get true and dependible results

 

[Rancherlee]

Re: Battery Testing

A good battery should be 12.6V fully charged and provide a minimum of 9.5V while cranking the engine over. Most parts stores will do a load test for free though.

 

[ebry710]

Re: Battery Testing

A good battery should be 12.6V fully charged and provide a minimum of 9.5V while cranking the engine over. Most parts stores will do a load test for free though.

Now that I think about it, that should have been my suggestion. Much better then buying, maintaining and storing one.