About the YR1035+ meter

[Solarod]

I recently received a YR1035+ meter and I wanted to see just how good it is. I have a Hioki LCR meter that was recently calibrated to compare to. One of the things I did was to see if the YR could measure the ESR of an electrolytic capacitor. First I measured the capacitor on the Hioki and this is what I got:

In another post I've seen it suggested that because the YR uses AC to make its measurement it may be measuring impedance rather than resistance. Hedges explained in another post what impedance is. The usual expression is Z = R + jX, so impedance has two parts, the resistance part R and the reactance part X. In the image above the Hioki meter is able to separate those two parts--Rs is the resistance part and X is the reactance part. Impedance magnitude is a vector combination of the two parts, and the magnitude of that combination is denoted |Z|; the Hioki only shows Z in the image above, but it's really displaying |Z|. You can see that the impedance magnitude is about 60 milliohms although the resistance part Rs is only 9.07 milliohms. If the YR were in fact measuring the impedance magnitude that would be a gross error when we really want to measure the resistance.

So, I'm happy to report that when I measured that capacitor with the YR, I got a reading of 8.1 milliohms--it is not fooled by that fact that the capacitor has a reactance part of -59.63 (minus sign because it's capacitive reactance) milliohms. That large reactance part is causing a few percent error, but this is an extreme case. A typical battery impedance won't have a reactive part that is more than 5 times as large as the resistance part! This all means that the YR is able to reject the effect of a reactive part and measure only the resistance, not the impedance magnitude.

I also compared the YR's performance when measuring a length of hookup wire. The Hioki read 5.6 milliohms, and the YR read 5.52 milliohms. I can't complain much about that.

 

[sunshine_eggo]

I have used a YR-1030 for important battery IR measurements for several years.

 

[Noday]

Thank you for the insights. I have an IM3536 that I bought used in Japan a while ago and I just received an YR1035+ from Aliexpress, I was curious about your results and I can confirm I got about the same results you had. I didn't expect that since the prices and quality of the two devices are very far apart. It looks like the YR1035+ can be used with confidence.

Anyway, I decided to buy the YR1035+ to have it on me when I move around, but unfortunately the unit came with a dead battery. The unit only works while connected by micro-USB. Is your battery able to take some charge?

 

[Solarod]

Here's a document put out by Hioki about their BT4560: https://www.hioki.com/download/32951

It talks about Cole-Cole plots and shows an example of one on page 2 of the document. The red line which is the Cole-Cole plot crosses the horizontal axis on the left at 1 kHz and that point corresponds to the resistance R1 of the battery model. At 1 kHz the resistance R2 can't be measured because the high frequency current injected by whatever meter you're using to measure resistance is bypassed by the capacitor C. But, even though AC is being used to make the measurement, if the frequency is reduced from 1 kHz to 1 Hz (yes, that's one Hertz), the resistance R2 can now be measured, which is what a DC IR measurement would see.

On the bottom half of page 4 there is a section titled "Checking the battery deterioration level" we see two Cole-Cole plots, a blue one and a red one. The blue one is for a new battery, and the red one is for a degraded battery. Notice that the measurement made at 1 kHz is at the left end of the plots where they cross the horizontal axis at about 30 milliohms, corresponding to the the R1 resistance, and this is the same for both the good and bad battery. So a measurement at 1 kHz can't really distinguish the bad from the good battery. However, if the measurement is made at 1 Hz, where the plots reach a minimum we get the value of the R2 resistance, which can tell us that the battery is bad.

From another document here is a chart showing the correlation between DC IR and AC IR when the measurement is made at 1 Hz. This is from measurements on small primary cells like AA flashlight batteries, and similar.

Now all we need to do is to persuade the manufacturer to make a version of the YR1035+ that uses an AC frequency of 1 Hz to make the measurement.

I can tell the difference in value of a battery IR just by using my LCR meter to measure the IR. At a frequency of 1 kHz, I measured the IR of a Duracell AGM LA battery as 24 milliohms, but at 20 Hz (as low as it goes) the IR was 40 milliohms, substantially larger. The YR1035+ got the same 24 milliohms as my LCR meter.

 

[Noordsolar]

CAn you make cell IR measurements with YR1035 of a cell in an existing battery - ie (1) all wired up and (2) when connected to to charger / or inverter. It should be able to as it has a very narrow 1 kHZ bandbass filter I 'm sure.

 

[RCinFLA]

Now all we need to do is to persuade the manufacturer to make a version of the YR1035+ that uses an AC frequency of 1 Hz to make the measurement.

The minimal Z magnitude freq changes based on electrode design thickness, condition of cell, temp of cell, and discharge load on cell. It needs to be swept over a frequency range. Generally, it goes up in frequency with heavier DC loading. There also can be more than one minimal point of slightly different values at different frequencies.

It's primary interest is to give an indication of ion diffusion depletion recovery time associated with overpotential voltage effects due to cell loading.

Overpotental vs current is caused by several factors within a cell, most significantly from cathode electrode and anode electrode ion migration which have different overpotential versus load. From a total cell measurement perspective, you see the combined internal components effects mixed together on battery terminal impedance.

To a user, the important info is how much terminal voltage slump there is versus load current on cell.

 

[Solarod]

A couple of interesting articles about measuring DCIR and ACIR by a Keysight engineer:

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