Yes with any of the charger/analyzers contact cleanliness, battery positioning and tension on the contacts (especially over time with springs that can change) are all factors that conspire to make consistency difficult.
Both with the MC3000…
That’s the part I believe you will find rather disappointing from a value perspective; but It will however be fun to play with 
Regarding the aforementioned results of my little ‘consistency / repeatability’ test, I will post a link to it in this thread. Were I not dealing with a sore finger, that would have already been done!
I wasn’t yet aware of other MC3000 threads here. I’m relatively inexperienced with this system, but sounds like I should learn to ‘subscribe’ to threads here!
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All of the above, certainly. I believe that reference was also addressing the fundamental matter of 4- vs 2-point / wire resistance measurements. While that is absolutely a valid / important consideration, I believe that some many fail to prioritize it correctly given all the considerations involved in the practical choice of what to use for routine cell testing - such as other fundamental criteria, such as exactly what property / parameter is being measured in the first place, which I believe is an even higher priority. I will explain that comment at some point soon.
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Wow! Looks like I not only have a lot of typing to do, but a lot of reading as well!! That’s OK. I come here to learn.
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The SKyRc Mc3000 thread is probably the best one to use for what you want to do.
BTW, I have a small favor to ask, for after you receive your impedance meter / tester. I’ve done a fair bit of studying (elsewhere) of late to expand my impedance measuring experience / knowledge with info specifically regarding Li-ion cells, which I know very little about, relatively speaking. I’ve done RF and audio apps, etc., but never cells / batts.
Something I haven’t run across / don’t have (surprisingly) but would very much like to is this: One example of a simple, same cell, A-B comparison of measured cell DCIR (like your MC3000 provides [and please use that just because I have one ‘like it’]) vs measured cell impedance @ 1kHz (like your new gadget likely provides). Since there is no constant or conversion factor I can use to compare the 2 numbers (which will also vary by cell type), it requires that someone measure it for me. The relationship will likely vary with the size (and perhaps type) of the cell.
It would be particularly nice if you could get those 2 numbers for 2 different cells. Ideally 1 should be an 18650, and the other should be a smaller cell, such as a 16340 or 14500. It would be good if they’ve been fully charged to 4.20V, but then allowed to settle a bit to their initial, stable resting voltage, just as good practice since the DCIR test puts load pulses on the cell. EDIT: You’ll want to use the same MC3000 slot for both tests as well.
If you would be so kind, I’d greatly appreciate that info. Besides, I know you’ll be looking for an excuse to play with it anyway:-)
I just now noticed this post, but…
It is a little ironic that this thread is about IR testing, and HKJ’s only beef(?) w/ the S4 was regarding that. However, this very well might be the best way for you to go even given that. Since the discrepancy he noted was fairly constant, and the readings it provided were consistent, your use of an offset to correct for the issue sounds OK. Having 2 units of the same type and thus having all your measurements comparable with each other would also be a major advantage in itself.
Do be cautious about one thing though (no matter what device you’re using).
" …MFG data specs…
Note my previous comment that one possible advantage to using one of these impedance meters being discussed might be comparability with some manufacturer specs, who have increasingly begun to specify ‘Internal Impedance’ (aka ACIR, aka 1kHz resistance, and others). rather than the more traditional DCIR, like the S4 measures. So regardless of what device one uses, to compare with mfg. specs first requires that one is measuring the same parameter. Then assuming you are, if your unit has an error offset, that can be applied. I think I’ve read that different manufacturers / suppliers or providing specs which specify either one or the other, and some are providing both. I haven’t really checked around, but apparently it varies at this time. Be sure to check, and they also use differing terminology / designations, just to make things more confusing.
Also important to keep in mind that it is yet unknown whether or not changes have been made to recent revisions (like V3, or whatever) which would correct that issue with the earlier model. I posed the question earlier in this thread, but I don’t think it’s been answered. If changes have been made / the issue corrected, the correction factor you mentioned may not be needed or appropriate, so keep that in mind.
Hope that makes sense. Let me know if it doesn’t.
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This
seems relevant here. Looks like an update to one discussed above.
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I will do that. As you said, I will want to play with the device. More importantly, at some point I want to be able to try and correlate the readings with my records from using the MC3000 over the years.
This was purchased through AliExpress. from China. So I am not sure when I will receive it. If you don’t hear somethin in two to three weeks, feel free to remind me…
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Yeah… and about $6 less than what I paid. Typical of my luck. But at least I was able to find a few review/test reports on the specific meter that I bought.
EDIT: I just notice the shipping charge. It would really be about $5 more than what I paid… The USB C port is nice. The extra digit for voltage…??. Accuracy claim… Well TBD.
Thanks in advance, and that sounds good. I guess my request won’t take you far out of your way, as it sounds as if you’ll be as interested in the results as I am, albeit perhaps for different reasons. I gather/believe our expectations regarding the results are likely very different, but we will be equally interested in them.
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What are your expectations? I am very curious.
I am not sure what mine are exactly. Though, I am quite sure they will be considerably different than what I am used to seeing from the MC3000.
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AX seems to have quite a few of these “cheap” IR meters…makes one wonder whether those MFG will calibrate each batch
I saw the price of a hioki battery tester such as the BT-3554 and …oh wow
but comparatively my uni-t ut139s is quite on par with my fluke basic multimeter
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If you decide to buy one of these ‘impedance meters’ (which I do not personally recommend for those with requirements similar to my own [testing and documenting the health / quality / condition / performance of cells for use in flashlights], I recommend choosing one that has been reviewed on lygte and has documented accuracy. Although most are very ‘cheap’, many are fairly accurate (sufficiently so) at doing what they do; but do choose wisely, especially when buying ‘cheap’ stuff.
That said, I believe you’ll find (as this thread develops in the near term - if you stay tuned for it) that the most important issue will not be accuracy (if you verify that as above), but will rather be what these devices actually measure, which is apples and oranges compared with the charger / analyzer you’re using. If you don’t fully understand the technical differences, I highly recommend you not buy one until you do. Those differences involve things well beyond comparability of data with other sources - that’s just the tip of an iceberg. IOW, I think if you buy one it will likely end up collecting dust in a closet in fairly short order; or if you decide to use it, you may not get the information you probably should be wanting to have if you’re using it for measuring cells for use in flashlights. There are however other uses for these devices for which they are indeed quite useful, if you have other applications / needs in mind.
I keep seeing this kind of thing in your posts, but you haven’t explained it.
If I can get reasobaly accurate and repeatable measurements of cell internal resistance using on of these meters that uses AC (1 kHz I think), why would it be any less applicable to our use of cylindrical cells and correlating that to the same parameters…
??? Are we not gathering information about those same things, just using a different method of getting the data?
Do you think that using AC IR measurement with a 4 wire system will somehow lead to different conclusions.
I am really curious as to your specific reasons for indicating that you believe that these meters may not be suitable for accomplishing the stated goals.
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Patience, @Mandrake50. I’m not only older and slower now, but am also somewhat preoccupied with other things of late. I believe my planned response (which I am still finishing formulating) will address all the issues you raise (and perhaps more), but it will likely be neither short, nor simple (to explain), so don’t expect that. It may well be somewhat long, and somewhat complex, because the issues behind my general statements involve fairly complex factors for the average reader (such as ‘complex impedance’). I’ve been researching and thinking, not typing. I don’t want to address these various issues piecemeal, as they are interrelated, and should be addressed in full context. I do, however think the info is worth documenting for those attempting to find answers to the questions I’ve been asking myself, which I believe are questions shared by many, and is info I’ve not seen documented in this thread (or anywhere else that I can recall). I don’t want to present my own conclusions / decisions without adequate explanation for such readers. I’m not that guy;-)
I don’t think you’ll have a single question after you read it (if I’ve done my job correctly), and if you do, I’ll address it easily in the context of what I’ve already stated by that point. There is method to my madness here.
You’ve already thought this stuff through, formed opinions / reached conclusions, and purchased equipment for the job. That train has left the station. Others may still be trying to answer the questions I had / have to answer, and possibly to make purchase decisions. Those people (if any) are why I want to document my conclusions, because I believe it would be of benefit to them. I know it would have been valuable info for me, and this is a rare case where I think I have info to offer which will advance the discussion significantly beyond where it is currently.
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My statement was based almost entirely on expectations already expressed previously in this thread by both of us. If you go back through this thread, you will find them. Instead of revisiting those statements, I would prefer to move forward and expand on them, which I intend to do.
The aforementioned tangential information may be found here, for those who might be interested:
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Those numbers look pretty consistent for the MC3000.
I did some tests on my Vapcell S4+ and YR1030+ (AC IR tester). I’ll post the results here instead of over in the MC3000 thread.
As you see from the data below, the S4+ isn’t that great at consistency (per slot or across the slots). Seems like my slot #2 gives the most repeatable values. As you can also see, the AC IR tester is very consistent.
I tested a cell with the highest IR and also one with the lowest.
16340 (protected)
| S4+ (slot 1) | S4+ (slot 2) | S4+ (slot 3) | S4+ (slot 4) | YR1030+ | |
|---|---|---|---|---|---|
| Test #1 | 153 | 143 | 150 | 157 | 147.6 |
| Test #2 | 175 | 159 | 165 | 154 | 147.6 |
| Test #3 | 173 | 164 | 181 | 175 | 147.7 |
| Test #4 | 187 | 154 | 168 | 205 | 147.6 |
Molicel P45B
| S4+ (slot 2) | YR1030+ | |
|---|---|---|
| Test #1 | 12 | 6.63 |
| Test #2 | 14 | 6.64 |
| Test #3 | 10 | 6.67 |
| Test #4 | 12 | 6.66 |
| Test #5 | 10 | 6.63 |
| Test #6 | 10 | 6.60 |
| Test #7 | 12 | 6.62 |
| Test #8 | 12 | 6.60 |
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