Harbor Freight 12V Battery/Alternator Tester: does it really work?

[slacktide_bitog]

I found this plug-in battery and alternator tester at Harbor Freight, which claims to be able to read battery and alternator voltage just by plugging it into the 12V cigarette lighter power outlet

How good is this plugin tester? Has anyone here used it or something like it before?

 

[RooflessVW]

I don't see why it wouldn't work.

I just use my DMM

 

[Creekside]

It’s just a meter with lights instead of a gauge. Isn’t accessory plug voltage regulated on newer vehicles? If it is then the alternator side may not be accurate but everything else should work fine.

 

[DriveHard]

Pretty straight forward, can also be accomplished with a simple multi meter.

 

[slacktide_bitog]

Pretty straight forward, can also be accomplished with a simple multi meter.

the best part is that HF has an actual mutlimeter for the same price as this thing, and if you're lucky enough to find a coupon, you can even get that multimeter for free

(I have that free HF MM)

 

[Cujet]

It is not uncommon for the cig ligher outlet to have some resistance and show a lower voltage under load.

Get a meter and measure at the battery. You can find meters just as inexpensively and they are much more helpful. Maybe more importantly, various cars and various battery types have different voltage requirements. Only a meter will give you the results you need for this.

 

[JeffKeryk]

My batteries let me know when it's time...

 

[JMJNet]

Get a load tester.
OR
Amazon have some fancy battery load tester, alternator, starter tester very economical.

 

[Furious]

AutoZone sells the OEM Tools Digital tester for $50, It is a good purchase for any DIY'ers or mechanic and tests many different types of batteries, it tests cold cranking amps, it will perform alternator tests.

Consider buying the OEM tools instead. Just because a battery has 12 volts does not mean it is good and without a decent tester you could end up stranded one day.

 

[Furious]

My batteries let me know when it's time...

Or hear me out... get a good tester and test your battery every few months or so that way when the battery is actually starting to fail you get it replaced while under warranty considering most decent batteries offer 3-5 year warranties now.

Or you can choose to lose money and ignore the warranty and wait until you are stranded.

 

[zzyzzx]

They make ones with digital readouts that give actual voltage. Get one like that instead.

 

[JeffKeryk]

Or hear me out... get a good tester and test your battery every few months or so that way when the battery is actually starting to fail you get it replaced while under warranty considering most decent batteries offer 3-5 year warranties now.

Or you can choose to lose money and ignore the warranty and wait until you are stranded.

My post #7 was kidding. I regularly service my batteries cleaning them and the terminals. I have 2 tenders for the cars that sit. I also believe in big fat negative cables. I keep a battery pack jumper in wifey's daily driver and another in the garage for trips or emergency use.

And old skool jumper cables in each of our homes.

 

[dishdude]

Get a load tester.
OR
Amazon have some fancy battery load tester, alternator, starter tester very economical.

This, you can't properly test a battery without putting a load on it. I've used the headlights and ignition to on without the engine running in a pinch...but that's far from scientific.

 

[LDB]

An actual meter that presumably does this and a lot more and for less money.

7 Function Digital Multimeter

Amazing deals on this 7 Function Digital Multimeter at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[eljefino]

This isn't for us. It's for our daughters off at college three states away.

 

[LDB]

This isn't for us. It's for our daughters off at college three states away.

Oh, so for a smart, capable young woman who could easily learn the basics of the meter. Even better.

 

[spackard]

Use it every time you’re driving, to get a feel of how the alternator keeps up with loads, and how quickly voltage drops once the key is shut off. I used one a long time ago and I could spot an alternator with bad diodes and a battery on its way out.

It’s not useful as pure idiot lights.