Internal impedance/resistance of batteries

Where can you get the SM8124 for 25 USD?

That is a typo, I forgot that I am using £ in my ebay setup. I will fix it.

Well, I use KT-98 and it measures IR in both directions, might be a better alternative if that ebay metter is supposed to burn the first time you switch poles.

It does not have a 4-wire connection, if you can use the rel button on the range, it might be useable.

This is a nice write up. It should be stickied or something for easy future reference.

Nice one HKJ, thanks. Very useful info to measure battery internal resistance with stuff we already have.

Very nice article! You answered a question I had. Thanks very much for the details. Sticky’d.

Accucel 6 has a way to measure IR supposedly. I have an Accucel, but haven’t done it, because it apparently involves using some additional cabling which I don’t think that I have. If I did do that, do you all think it would be an accurate IR measurement?

It will probably do a DC measurement at a unknown current. If it uses four wires and you connect them correctly to the battery, I would expect it to do a accurate measurement.

But if it only uses two wires, it will not be very accurate.

What is most interesting is the repeatability, i.e. does it give the same reading (or very close) each time. If it does, you can use it to follow the ageing of the batteries.

Hi,

I didn’t look into it much, because, like I said, I got info that you had to use the side-port and I think cable using something like a balanced charging type configuration, and I only have the default cables that came with the Accucel. But, they do make a deal about it, with even a small yellow flyer that says it’s like the most important thing to measure (but no instructions how to cable) :).

Thanks. If I ever get around to doing it, I’ll post about it.

Jim

Thanks for this great info HKJ!

Thanks HKJ for a very interesting read! Of course, I’ll have to read it about 10 more times for 25% of it to sink in….

+1 except I’d be lying if I understood 2%.

As usual, sure I can learn new thing by reading HKJ post. Thanks for sharing, HKJ.
I had long wanted to have easy way to keep track on my battery condition, but recently lazy to keep track on them.

I think I remember seeing an iCharger 208B in one of your many informative posts. Have you looked at its IR measurement function, and if so, what do you think of it?

Yes, I have a iCharger 208B or two. They can measure IR, but I have not really used it or analysed it. It uses two wire and will give an error due to that.

Thanks for the quick response. I will have to study the OP more closely to learn about what the error may be.

meant for capacitors but does ok for batteries.once you get the feel for good esr readings for a certain cell go/nogo tests are fast.like when grading laptop pack salvage cells.
http://www.amazon.com/Anatek-Corporation-blueesrkit-Blue-ESR/dp/B005NB6CKS
i have one of the original kits from 15+ years ago.great tool.

I’m new to all of this but would like to replicate this set up. Would you be able to explain how the resistance/capacitor boxes were built.

I bought a Reed R5001 LCR meter for measuring impedance. Can I use that with this set up?

Thanks!

That is just resistors/capacitors connectors to the binding posts. When doing a lot of different test setups this is much easier than soldering the wires each time.

Even though I have a bunch of electronic loads, I uses that resistor box all the time.

Probably not, the problem is the battery voltage. When measuring the internal resistance you are not going to work on a voltage free circuit, due to the battery it will have about 4 volt.