LiitoKala Voltage reading wrong by -0.30V

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barns

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Dec 23, 2018
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Did anyone have the same experience? I was testing 4 18650s and just an hour after plugging it in charger displayed NULL, which was weird because it takes way more than that. When I plugged the batteries in they couldn't be recognized. I used my MM and I found out that itovercharged the batteries I was testing to 4.55 volts. I tried putting a 4.15v batteryand it was reading it at 3.90v, an hour later I tried again the reading was 4.02v, severly under the MM reading. My Opus BC3100 was only had a 0.03v discrepancy from my MM.


Very weird that the Voltage reading is below under by 0.30v but it can't recognize the ones it overcharged to 4.55v.
 
Sounds like its ready for the trash bin... those testers dont last forever, I have lost a couple to heavy use. Once they start acting up I retire the unit.
 
CrimpDaddy said:
Sounds like its ready for the trash bin... those testers dont last forever, I have lost a couple to heavy use. Once they start acting up I retire the unit.
Click to expand...

Oh boy, it's only 8 months old and have testedless than 200 cells.
 
barns said:
CrimpDaddy said:
Sounds like its ready for the trash bin... those testers dont last forever, I have lost a couple to heavy use. Once they start acting up I retire the unit.
Click to expand...

Oh boy, it's only 8 months old and have testedless than 200 cells.
Click to expand...

I find what ended up killing mine are heaters... some cells get so damn hot when testing I think it ends up damaging the tester.

Maybe you just got a bad one... I have notexperienced a significantvoltage reading issue with mine.
 
thunderheart said:
barns said:
I used my MM
Click to expand...

What multimeter do you use?
Click to expand...

Cheapest DMM I can find on my local hardware. I also have an Opus and a discharge tester bk586and all three are within +-0.03 volts. The Lii 500 is not only reading low by 0.3v, it isalso inconsistent and unable todetect the batteries it overcharged.


CrimpDaddy said:
barns said:
CrimpDaddy said:
Sounds like its ready for the trash bin... those testers dont last forever, I have lost a couple to heavy use. Once they start acting up I retire the unit.
Click to expand...

Oh boy, it's only 8 months old and have testedless than 200 cells.
Click to expand...

I find what ended up killing mine are heaters... some cells get so damn hot when testing I think it ends up damaging the tester.

Maybe you just got a bad one... I have notexperienced a significantvoltage reading issue with mine.
Click to expand...
Heaters are unlikely. I never leave cells unchecked. I do an IR thermometer reading hourly so no little chance of heaters.
 
I agree with you, I think there is something wrong with the charger. Perhaps you just got a bad one, and I would personally retire it at this point. Im glad you are cross comparing with other devices, but the only advise I can give is invest in a decent DMM. I've used the spectrum over many years and if there is one bit of wisdom I can pass on is that the level of confidence and trust in a reading goes a long way. The count and resolution is really nice to have, but accuracy matters as well depending no what you are doing.

With a high resolution / high count meter, you can watch grass grow. The activity is generally pretty boring until you can see it move. The UT61E delivers a lot of that at a budget, 22,000 count meter. Great for what we are doing, monitoring charge/discharge and other activities.

You don't need to spend a lot, but here are my two recommendations.

~$50-$100 price points

UNI-T UT61E

Import market Fluke 17B
https://www.aliexpress.com/item/32802251073.html?spm=a2g0s.9042311.0.0.27424c4dtaoJZM
 
Check your multimeter battery, and leads. A flat battery can make your multimeter do all kinds of funny things. Really cheap multimeters are usually best avoid.
 
barns said:
I appreciate the MM concerns but that's not the issue.
Click to expand...

There are reasons why most would jump to the conclusion of your MM. I'm not certain, but I don't really think an 18650 could even hold 4.55v. I sure wouldn't even like to test it.I imagine somewhere around 4.3-4.4v it would just start burning off the charge as heat. The cell most assuredly would be hot when removed from the charger. It would most likely trigger the CID.

If you were sure that a cell actually hit 4.55v, I would discharge and bin it. The useful life has most likely been cooked out of it. I would definitely handle with care, as it most likely will have some pressure built up inside.
 
Geek said:
barns said:
I appreciate the MM concerns but that's not the issue.
Click to expand...

There are reasons why most would jump to the conclusion of your MM.
Click to expand...

Its a classic case of MM denial Ive suffered though it for years. I now have at least 4-5 meters just to make sure my others are notlying to me.
 
CrimpDaddy said:
Its a classic case of MM denial Ive suffered though it for years. I now have at least 4-5 meters just to make sure my others are notlying to me.
Click to expand...

Yep I've had my share of MM doubt till I bought 2 things well 4 things actually

1.A Voltage reference unit and a resistor reference.

image_tuvlos.jpg

image_ttnbba.jpg


2. A decent Bench MM. well 2.

image_syoson.jpg

:D :D :D
Wolf
 
Wolf said:
CrimpDaddy said:
Its a classic case of MM denial Ive suffered though it for years. I now have at least 4-5 meters just to make sure my others are notlying to me.
Click to expand...

Yep I've had my share of MM doubt till I bought 2 things well 4 things actually

1.A Voltage reference unit and a resistor reference.

image_tuvlos.jpg

image_ttnbba.jpg


2. A decent Bench MM. well 2.

image_syoson.jpg

:D :D :D
Wolf
Click to expand...

Nice toys. Don't have the budget for those unfortunately. Where'd you get the Voltage reference unit?

I've got 8x INA219 sensors for my DIY charger/discharger project. I hope the readings from those will be good enough to confirm thatmy MM and Opusare not that broken.
 
barns said:
Nice toys. Don't have the budget for those unfortunately. Where'd you get the Voltage reference unit?

I've got 8x INA219 sensors for my DIY charger/discharger project. I hope the readings from those will be good enough to confirm thatmy MM and Opusare not that broken.
Click to expand...

Voltage reference unit.AD548

https://www.amazon.com/gp/product/B00NL419KW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Just googleAD548 and you will find many variation to it.

The INA219 ar good little units. They have their own internal reference V I believe.
Just got to write the sketch and still do the calculations and as I have found out with V dividers and even the ADS1015 and/or the ADS1115.
Still had to do some offset calculations. So having the fluke meters helps.
You can occasionally find a good deal on a decent bench MM for under $100 on ebay.

Wolf
 
barns said:
CrimpDaddy said:
Sounds like its ready for the trash bin... those testers dont last forever, I have lost a couple to heavy use. Once they start acting up I retire the unit.
Click to expand...

Oh boy, it's only 8 months old and have testedless than 200 cells.
Click to expand...

Donate it to me for repair?
 
Geek said:
barns said:
I appreciate the MM concerns but that's not the issue.
Click to expand...

There are reasons why most would jump to the conclusion of your MM. I'm not certain, but I don't really think an 18650 could even hold 4.55v. I sure wouldn't even like to test it.I imagine somewhere around 4.3-4.4v it would just start burning off the charge as heat. The cell most assuredly would be hot when removed from the charger. It would most likely trigger the CID.

If you were sure that a cell actually hit 4.55v, I would discharge and bin it. The useful life has most likely been cooked out of it. I would definitely handle with care, as it most likely will have some pressure built up inside.
Click to expand...


are you sure????

I think pretty much every cell will go to 5V.

wouldn't want to do it by accident. and I don't do it on purpose. but I've found cells dumped from 'harvesters' (shame!) at this SoC.. it's not the end of the world ... but definitely out of spec.
 
DCkiwi said:
Geek said:
barns said:
I appreciate the MM concerns but that's not the issue.
Click to expand...

There are reasons why most would jump to the conclusion of your MM. I'm not certain, but I don't really think an 18650 could even hold 4.55v. I sure wouldn't even like to test it.I imagine somewhere around 4.3-4.4v it would just start burning off the charge as heat. The cell most assuredly would be hot when removed from the charger. It would most likely trigger the CID.

If you were sure that a cell actually hit 4.55v, I would discharge and bin it. The useful life has most likely been cooked out of it. I would definitely handle with care, as it most likely will have some pressure built up inside.
Click to expand...


are you sure????

I think pretty much every cell will go to 5V.

wouldn't want to do it by accident. and I don't do it on purpose. but I've found cells dumped from 'harvesters' (shame!) at this SoC.. it's not the end of the world ... but definitely out of spec.
Click to expand...

I had a LiPo that I accidentally overcharged, LiHv setting - 4.35v instead of 4.2. It swelled up like a balloon. I don't know what voltage it hit, as I disconnected the charger immediately.
 
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