ZB2L3 not counting

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VanUnamed

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Joined
Dec 25, 2023
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18
hello!
I have bought 6 of these modules, and one of them does a weird thing.
the resistor heats up, voltage drops, but it does not show a load on "A"
nor a reading on "Ah" while discharging.
Any idea what might be at fault?
 
I have a couple dozen ZB2L3 testers on my test board. Over the course of a couple thousand cells, I have had one fail just as you describe. It appears to work, but the digital readout doesn't display anything. (You don't mention voltage, but I assume yours is like mine and just does not display at all.) I haven't ever investigated -- I suspect there's a fault in the display or in the board/wiring to the display. I just don't use that slot on my test board anymore. For better or worse, they are basically disposable devices. Replace it, and consider ordering a spare or two to have on hand in case it happens again.

Cheers, John
 
your resistor is not working correct, replace resistor and or check your connections.
Also it could be a soldering fault on your side.
What i noticed during the years is that the zb's are connected via the - bus somehow.
(i even order diodes)
So there is a chance that the other zb's will count that cells mah to their counters.
Also their is a chance that the other zb's will use that zb its resistor.

What i would do:
check resistor and connections.
If that was not helping:
Check the feeding v line into your zb's
If all is correct--->replace.
I bought 100 of them in the course of years, never had this,
But i was the cause of several ones.
Incl spiders that wanted a warm place in my shed.......
wrong soldering.
Some small connection between here and there.

I would bed on my first sentence: resistor connection.

With best regards Igor
 
thanks.i tried to solde the resistor even, no luck. contacted seller, maybe i get a refund.
 
Ok, i found the fault. I have damaged the 360 ohm resistor that feeds the lm321. i had no idea the module had a + and - pads to connect voltage, and i just soldered the plus onto the resistor and damaged it.
now, i am unsure about something. I did not find a 360 ohm smd resistor and used a 330 one instead.
the module did count and work, but i am unsure if it is counting correctly? I saw different versions of this module and some have all 330, and other all 360.
this is my module
https://imgur.com/zr7ghV9
this is another from the internet
module with 330
never mind how ugly it looks, i was just testing the theory. I do have an air gun to properly flow it.
Still, it seems the configuration for the lm321 is "low pass active filtering"
So i am just unsure if this difference between resistors is significant or not. the resistor i damaged came from the +5V rail and went to pin 5 *VIN of the LM321.

Thanks for your help!
 
thanks for the replies! I changed the 360 resistors with 330 on the 1 module, so all are 330. the ones i removed, i used to repair the other one with the one damaged. now it all works!
Also, the modules are a bit "off" with voltage read, but i know these should in theory be calibrated.
But from what i read, it does not really matter. consistency is more important than accuracy.
 
VanUnamed said:
thanks for the replies! I changed the 360 resistors with 330 on the 1 module, so all are 330. the ones i removed, i used to repair the other one with the one damaged. now it all works!
Also, the modules are a bit "off" with voltage read, but i know these should in theory be calibrated.
But from what i read, it does not really matter. consistency is more important than accuracy.
Click to expand...

For giggles, you might grab a few cells that you previously tested on the ZB2L3 unit before the repair, and now re-test the same cells on the unit after the repair. See how close your two readings come out. If you happen to have a sample of ten or twenty, you might have enough data to establish a trend or a "correction factor" for the repaired tester. Just a thought. I very much agree with the "consistency over accuracy" position. If you're using multiple ZB2L3 units, you want to know that their readings are pretty close to one another, or else you won't know whether you have consistency. (If tester A routinely reads out 10% higher than tester B, then comparing batteries that came from both testers will not be an accurate comparison as you build your pack.)

For what it's worth, and I've said this elsewhere around here, I tested a large number of cells (several hundred) in both an Opus type tester and on my ZB2L3 test board. My goal was exactly to look for whether there was a correction factor I needed to apply depending on which ZB2L3 tester is used. I did find consistent differences in test results, varying by ZB2L3 unit. Referring to my old spreadsheet, it looks like the correction factors (across 24 separate ZB2L3 units) averaged about 4.5% higher readings than the Opus and LiitoKala testers. (This is despite doing the calibration routine on the ZB2L3 units with a benchtop power supply -- I was never very convinced that the calibration did anything.) The vast majority of my two dozen testers read between 3% and 6% higher than the reference testers, with only one unit showing an inaccuracy below 1% and only one unit showing an inaccuracy higher than 7%.

Now...what's to say that the Opus or LiitoKala should be treated as any kind of a reference? Fair question. Again -- consistency over accuracy. I just wanted to know if one of my ZB2L3 units was reading far out of line with the others -- and if so, whether it was consistent enough to adjust its result based on a comparative average.

Cheers, John
 
I bought more modules, and these all have a 330 ohm resistor. So i should get like 5 cells, test them on the 360 ohm ones, and then the 330 ohm ones?
 
VanUnamed said:
I bought more modules, and these all have a 330 ohm resistor. So i should get like 5 cells, test them on the 360 ohm ones, and then the 330 ohm ones?
Click to expand...
Yes. I think you need a sample size larger than five, though. At least ten or twenty. (It's been a long time since I took statistics, but I imagine that if you get to twenty data points through both the 330 and 360 testers, you'll start to have some meaningful significance in your data.)

This is slightly complicated because you're really looking for two things. First, you're looking for whether the 330 ohm testers give you the same results as the 360 ohm testers -- and if not, you're looking for whether the difference is consistent enough to "correct for" the difference when you're no longer testing batteries twice, once in each tester.

However, you're also looking for whether your testers are fairly consistent when compared to one another. To do that, you either need a reliable / trusted reference that you compare each ZB2L3 against, or you need to consider testing a sample of cells repeatedly -- each battery tested once in each ZB2L3 -- and comparing the results. Assuming the battery itself is reasonably consistent, this will tell you what variance you have between the tester modules. Again, if you see real consistency in the differences between testers when controlling for the battery, you can establish a correction factor to apply to each tester to give you consistent / fairly comparable results when testing large numbers of batteries.

Hope that makes sense --
Cheers, John
 
Ok i made a test. I got 4 cells, and tested 3 times on the 360 ohm type modules. i got readings with a + or - 40-50mAh from one another.
so my cells were around 1700~1750mAh. But when these were tested onto the 330 ohm one, it read 1900+. So those 30 ohms are indeed significant.
On the bms from original laptop batteries, i can only find 330 ohm resistors. I do have 360 ones but are a bigger package than the one on the modules, hence = more wattage rating resistors.
 
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