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Any experience with Autoxray EZ-charge?

I’ve already got an Autoxray scantool and just saw after the software update that I can use the EZ-charge battery tester attachment. I’m wondering if it’s worth the extra expense for that attachment vs just a voltmeter which I already have.

I’m not familar with the EZ battery tester attachment that goes to the Autoxray. But unless it has a way to load the battery, I wouldn’t purchase it. It might simply turn your scan tool into a digital volt meter as you suggested. The better way is to buy a battery voltmeter/load meter. This little device will let you put a load on a battery as well as check voltage. I bought mine for 20 bucks at Harbor Freight, and does almost everything a more expensive unit will do for you, providing you know how to properly read a volt meter. You can’t tell if you’re putting a 50 amp load on the battery or a 75 amp load, but who cares, it does the job.

If it meaures the battery’s capacitance? Buy it! This technology is the latest in testing the battery condition without having to recharge the battery.


Yeah, it does something like that. Here’s what it supposedly does.

* Battery Conductance Tester for use with EZ-Scan
* Tests for battery condition, voltage, and available power
* Voltmeter Function with high and low voltage capture to test the starting and charging system
* CCA, CA, EN, and DIN battery rating systems for foreign and domestic vehicle batteries
* Conductance technology helps find weak batteries before they fail
* Safe, Fast, and Simple to use
* Uses technology required by car manufacturers worldwide for battery warranty testing

Sounds like it might be useful.

How much for the upgrade?


It’s just under $30 for the 1st generation attachement. Current version, 2nd gen., is about $45. These are ebay/amazon prices. Retail is running $100+ I believe from a lot of places.

If you feel that you need this feature on your scanner, it’s worth it.

Just to buy a stand-alone battery tester with these features costs over $200.00.


thanks for the input

Mr. Tester is way more knowledgable than I am, but the language “Conductance technology helps find weak batteries before they fail” makes me leery. What the heck is “conductance technology”. If we’re talking linear circuits, then conductance is just the reciprocal of resistance.

I look forward to becoming educated about this new technology.

It did sound a bit odd to me too. Found some info online though.

Impedance and Conductance Testing

The discussion about the battery equivalent circuit in the section on Performance Characteristics shows that we can expect the battery impedance to increase with age.

Battery manufacturers have their own definitions and conventions for Impedance and Conductance based on the test method used. Though not strictly correct they serve their purpose.

The test method involves applying a small AC voltage “E” of known frequency and amplitude across the cell and measuring the in phase AC current “I” that flows in response to it.

The Impedance "Z " is calculated by Ohm’s Law to be Z=E/I

The Conductance “C” is similarly calculated as C=I/E (the reciprocal of the impedance)

Note that the impedance increases as the battery deteriorates while the conductance decreases. Thus C correlates directly with the battery’s ability to produce current whereas Z gives an inverse correlation. The conductance of the cell therefore provides an indirect approximation to the State of Health of the cell. This measurement can be refined by taking other factors into account. These are outlined in the page about State of Health.

In addition to impedance and conductance these tests will obviously detect cell defects such as shorts, and open circuits.

These test methods can be used with different cell chemistries however different calibration factors must be built into the test equipment to take into account differences in the aging profiles of the different chemistries.

Impedance and conductance testing are reliable, safe, accurate, fast and they don’t affect the battery performance. They can be carried out while the battery is in use or they can be used to continuously monitor the battery performance, avoiding the need for load testing or discharge testing.

Here’s the site if your interested in reading more of what they say…

Thanks. (Boy , am I lazy – or maybe internet incompetent.)

So, the incremental (that is, “small signal”) impedance (or conductance) increases (decreases) as the battery degrades. That’s reasonable. And it’s reasonable that if you test a bunch of batteries you can get values for the impedance as a function of whatever degraded parameter you want (e.g., CCA). BUT, it’s different for each technology (but there’s hope because most low-volt automobile batteries are lead-acid) and the btty makers have their own definitions (and test methods?). Looks like it might be real, but maybe have to wait for the degradation curves to get developed enough to be generally available.

I’ll read more of the web page.

GM made the battery conductance tester a essential tool back in 1997. I have been preaching the value of the conductance test method for months on this Forum with little results.

The capacitance tester sounds like a great tool, and I would like to have one. I’ll have to put it on my grocery list.

I can see how conductance testing can give an indication of sulfation on the plates, but it won’t help predicting if and when the material that falls from the plates builds up enough to short out a cell.

Well the article quoted in rripstop’s post does say that the gadget “…will obviously detect cell defects such as shorts, and open circuits.” But so will my ancient analog VOM. (Still, if you’re gonna have the gadget, it might as well also do the simple things.)

And I still get huffy about their calling it “conductance testing” instead of “impedance testing”. That sound like marketing “water for gas” as “HOH”.

And I think batteries might have capacity, but not capacitance.