That helps. Thanks.
Was just wondering why the difference.
@klrman and ActiveAI, thanks for the compliments.
I should get myself a resistance tester, but I already have a 4 wire tester that does the job quite well.
Thanks BlueSwordM for suggesting a SM8124A battery resistance tester. Today mine arrived from AliExpress.
It came with a pouch by the way, although another than displayed in the sellers picture. My 30Q test 7 mOhm and my VTC6 test 6 mOhm. I guess these cells (both from nkon.nl) are real 
Did it come with the new two-prong probes? This seller is displaying pictures of both the old and new SM8124A models together. Thanks!
Can anyone please post a link to the SM8124A we can 100% trust? I mean there are how many sellers on AliExpress….six, seven?…who offer this nice device, sometimes with different brand names, sometimes without the “A”, sometimes with two cables on both probes, sometimes just one cable. I find it hard to decide whom to trust.
I was unfortunately unlucky with some of these Dolidada batteries…claimed to be IMR-55A cells (like Shockli/Keeppower) but they turned out to be of rather poor quality with much less capacity and even less power drain capabilities.
^
Good question. I ordered one from the same ad as slowtechstef.
Thank your klrman, BlueSwordM, tatasal, and others for your contributions to this thread. Been wanting a decent budget IR meter for a good number of years now.
I think it’s worth mentioning that the resistance values from this $50 AC tester should not be compared to other chargers and things that give resistance.
AC resistance measurements are pretty far apart from DC load resistance measurements.
Article:
So while this device is still useful it is not giving you the same measurement you might find in other sources. Also, I don’t think it is as good of an indication of the max discharge a battery can sustain. (like what HKJ or Mooch are giving you)
+1
I forgot to mention. The resistance measurements are at AC 1kHz sine wave. So while accurate, the resistance numbers are often measured to low.
A 4-wire constant current tester is the only way to measure the real DC load resistance measurement.
I read through the article you linked and it was helpful. Thanks. Fortunately, there is a lot you can do with AC resistance measurements, such as:
- Measure new cell when you first get them, and then take periodic reading afterward to monitor their health.
- Compare measurements against the battery's datasheet to determine if it is in specification. For example, the Samsung 30Q datasheet identifies a typical 1 kHz AC resistance specification of 13.13 ± 2 mΩ. The SM8124A I recently purchased measured my six Orbtronics 30Qs with an average resistance of about 11.5 mΩ (See Table 2.), which is within the datasheet specification. I was shocked that my $50 AC tester was able to provide measurements with this seeming accuracy. Perhaps this is a one-off fluke.
- Compare a known battery with one that is suspected of being a fake. For example, if a battery measures considerably more AC resistance than a real 30Q, then it is probably not a 30Q.
Update: I saved this post too quickly and had to make edits. Thanks!
ActiveAl, those numbers are really close to the spec sheet. I would say more than good enough for a $50 tester, especially considering the consistency of the readings which is what I really like about it. My numbers are higher on my cells as they are all protected, but soon my 30Q's will arrive and I can see what numbers they read.
I have the latest model with the two prong cables that BlueSwordM linked in post #3 https://www.ebay.ca/itm/Battery-Resistance-Voltmeter-Internal-Impedance-Meter-LCD-Rechargeable-SM8124A/273104104104?hash=item3f9645eaa8:g:BEIAAOSwWmNapAyf
I also purchased mine from the same ebay seller (i.e., tangzhimin1008) as Kirman (link above). We got the new model with the double-pronged probes and, so far, it is exceeding my expectations in performance. I used it to determine that six 30Qs from the LiitoKala Factory Store were probably fakes. In this endeavor, my SM8124A readings were very consistent and reasonable. See Table 1 and Table 2 in this post for my data. Note that the average reading for the six real 30Qs (Table 2) was within the typical 1 Hz AC specification of 13.13 ± 2 mΩ given in the 30Q data sheet. This blows me away.
The cheapest purchase alternative for a SM6124A appears to be from this Ali Express Store. But there is no confirmation that they are selling the new model. Suspiciously, this store is displaying pictures of both the old and new models.
Did you get the SM8124A with the two prong-probes or the predecessor without the „A“ and single-prong probes?
Has HKJ already put an eye on this fine device?
I sent the following message to the AliExpress store in question (NewBeautifulLife Store, #1183073) last night:
Reference: Battery Resistance Voltmeter Internal Impedance Meter LCD Rechargeable Battery Impedance Internal resistance Tester SM8124A
Are you selling the newer version of this meter that has the two-pronged probes, or the older version that has the thicker single probes? The reason I ask is because you have both versions pictured on the product page. Thanks!
And got the following response this morning from Summer Sun:
Just the new version SM 8124A with two pronged probe.
After receiving this documentation, I would be willing to take a chance on ordering from them to get the best known deal on a SM8123A. Thanks!
Thanks for asking. I just bought one via your link.
One thing I noticed with the newer version is that you can't test eneloops as the prongs are too far apart. Older version with the single prong could do that, but I purchased this for lithium batteries so it's fine.
Good point. I noticed that you can't test button top Li-ion cells either - the probes are too far apart. But never-the-less, I believe the new version may be more accurate.
You can test button tops, but in my case I needed to use eyeglasses to make sure the probes make contact. A little tricky but I could successfully test all of my button tops Li-ions in no time. Trick is to avoid the vents on the button tops and the two pins will have enough room to make contact.
Talked to the seller and they may contact the manufacturer of the sm1824a and ask if they can make a slip on adapter for smaller batteries for us to use. I think it would be very useful.
You're right about the Li-ion button top batteries, Klrman! Thanks!
An adapter is a good idea. One could probably measure any additional resistance that would result and then allow for it. I would buy one if it was just a couple of bucks. Take care my friend!