RC3563 Tester: Inconsistent Readings and Voltage Deviation on Molicel p42a - Seeking Guidance

[Moroz]

Hello, thank you for accepting my forum membership request. I purchased an RC3563 based on @Wolf's recommendations. Upon receiving it, I tested it on my 50 new Molicel p42a batteries. The internal resistance and voltage results are inconsistent. When I remove and reinsert the battery on the holder and wait for 3 seconds, there is a fluctuation of 0.010 to 0.030 milliohms, either increasing or decreasing. I observe the same variations with the probes provided with the tester. Additionally, the voltage result deviates by 0.015V from my highly accurate Aneng AN870 voltmeter. Is the RC3563 defective? I made this short video to illustrate the issue.

Should I return it to the seller? Thank you for your help!

 

[Wolf]

Fist off welcome to the board @Moroz

The internal resistance and voltage results are inconsistent. When I remove and reinsert the battery on the holder and wait for 3 seconds, there is a fluctuation of 0.010 to 0.030 milliohms, either increasing or decreasing.

Of what I see from your video there is no inconsistency in the voltage readings, first battery always showed 4.162V and the 2nd battery was 4.159V at both measurements. Compared to your "highly accurate" Aneng AN870 voltmeter yes there is a difference of about 0.015 milli volt.
That discrepancy can be adjusted on The RC3563. Go into your menu option 2 and hit the plus or minus on the buttons till your readings match your Aneng AN870 with an accuracy of 400mV/4V/40V(+/-0.5%+4) Reasonable accuracy for the price. Oddly enough the RC3563 also claims to have an accuracy of 0.5%.
So lets go with your first measurement of 4.162V. 0.5% plus would be 4.18281V and 0.5% minus would be 4.14119V. Quite a spread I would say. So your deviation of 0.015V between meters is acceptable.
So compared to my Agilent 34401A with a DC basic accuracy of 0.0035% my RC3563 is quite on the money I would say considering the Agilent costs 20 times more than the RC3563 I think that's pretty good for this inexpensive piece of test equipment.
As far as your IR fluctuating 0.010mΩ to 0.030 mΩ at that low of a resistance a speck of dust could change that or merely your body heat handling the cell. Also since you are measuring really low IR ( 8mΩ to 9mΩ) I would set the scale to 20mΩ not Auto, see if that makes a difference. Now if you where to see a difference of 1mΩ to 2mΩ I would be concerned.
Wolf

 

[OffGridInTheCity]

Hello, thank you for accepting my forum membership request....

Welcome and very interesting post - thanks for sharing

 

[Moroz]

Hello @Wolf, okay, this is reassuring. I followed your advice and calibrated the tester. I thought the resistance test would always be perfectly identical, just like the voltage test, with 3 decimal places. I will keep this model.

 

[Stingray]

So compared to my Agilent 34401A with a DC basic accuracy of 0.0035% my RC3563 i

from 1 to 100V the difference 0.0035%?
the problem with my - it is not possible to calibrate it to full range my previous measurement

 

[Wolf]

from 1 to 100V the difference 0.0035%?

That is the accuracy of my Agilent 34401A


Not my RC3563. Which is only 0.5%

If I recall correctly you have a VR1220H which does not calibrate the same way as the RC3563.
In either case you have a special need to measure up to 120V I believe.
Most of us don't have that need so I concentrate on the 0V to 5V range which is what is important to me/us.
Therefore the RC3563, YR1035, ER-D, or any equivalent reasonably priced IR/V meter with reasonable accuracy is better than having no IR measuring device. I suppose in your case the ""accuracy" of the RC3563 decreases to >0.5% after 18V.
As said before most of us do not need or require that high of a voltage measurement with an IR reading.
If I want to measure my whole battery voltage ( ≈ 48V to 57V) I certainly don't use the RC3563 to do that, I rather use my Fluke 8842A.

I/we tend to focus on 1 cell at a time rather than a bunch of cells in series or parallel. In my case I want to know the IR and voltage of each individual cell and for that measurement the RC3563 in my case is perfect.
Wolf

 

[Stingray]

my whole battery voltage ( ≈ 48V to 57V) I certainly don't use the RC3563 to do that, I rather use my Fluke 8842A

I have 3 different now:
ER-D is very accurate and small but only up to 30V
RC3563 for voltage up to 100 also show IR and more or less well (even on a working UPS), +PC connection.
VR1220H can measure voltages up to 120V, but!!! IR measurements of this high-voltage battery do not correspond to reality (maybe UPS interferes, but if you disconnect the battery there is no reason for VR1220H).
I didn't buy the yr1035 when it was calibrateable.
As far as I understand the sold ones now have a locked calibration, and if I don't like the factory setting, I can't change anything.