Simple guide to using a DMM for measurements

[5S8Zh5]

Great job HKJ. I was wondering . On the ZTS battery tester under 3.6v you see listed a number of batteries but not 14500. My aw 14500's are 3.7. Does it matter ?? . Can the 14500's be tested in the 3.6 spot??

Yes, it can, it is about the same as RCR123A/16340.

I was reading the LiIon Battery tester section, and saw that you were using the ZTS MBT-1. I have the ZTS MINI-MBT, and it has the same 3.6V Lithium-Ion RCR123A, 18500, 17650 terminal for 14500 batteries. I was reading BU-409: Charging Lithium-ion - Over-discharging Lithium-ion: "Li-ion should never be discharged too low..."

Which percentage on the ZTS should be used for when it's time to charge a 14500 LiIon?

 

[HKJ]

I was reading the LiIon Battery tester section, and saw that you were using the ZTS MBT-1. I have the ZTS MINI-MBT, and it has the same 3.6V Lithium-Ion RCR123A, 18500, 17650 terminal for 14500 batteries. I was reading BU-409: Charging Lithium-ion - Over-discharging Lithium-ion: "Li-ion should never be discharged too low..."

Which percentage on the ZTS should be used for when it's time to charge a 14500 LiIon?

I have not checked it but 0% or 20%. I will expect 0% to signal empty, but not necessary over discharged.

 

[5S8Zh5]

I have not checked it but 0% or 20%. I will expect 0% to signal empty, but not necessary over discharged.

Thanks. ...

 

[Crazyeddiethefirst]

Hi CPF & HKJ,
I have been using a DMM for years, thanks to learning of the importance of matching in multi-cell lights from CPF. I recently added a ZTS to measure load. Because I have an extensive collection of lights and rotate their use, I have a maintenance schedule for all lights to have threads & O rings lubed, a quick polish with a protectant and I check the cells. I have over 20 Surefire multicell lights and when testing I was shocked to find Surefire CR123A cells that measured 3.16 V on both cells but under load testing with the ZTS they only showed 20% capacity. This occurred on 3 different lights. A fourth light measured 3.12v on both cells but under load 1 cell was 20% and the other 60%. The remaining lights were all above 3.0v with 100% on load testing. I repeated all tests multiple times to rule out poor contact. None of the batteries are more than 3 years old. Any idea why the voltage would be good but under load fail? Am I correct in assuming these batteries should be moved to my Surefire Hurricane lamp or Joule thief since their runtime could leave me stranded? Thanks for any information you can provide.

 

[SilverFox]

Hello Crazyeddiethefirst,

If you are up for an experiment...

Test your low cells and note the ZTS value associated with each cell that is in question.

Take a cell that showed low capacity on the ZTS and put it into a single cell light that draws reasonable current. If you don't have any, pick two of the cells that showed low capacity and put them into a multi cell light.

Next turn the light on for 15 - 30 seconds, then shut it off.

Take the cells out and let them rest for 30 minutes, then test them again with the ZTS tester.

If the value from the ZTS increases, there is a good chance the cells have developed a pacification layer inside. Once you burn this layer off the cells may perform as normal, at least in the short term.

Tom

 

[Crazyeddiethefirst]

Tom,
Thank you for the guidance! I have plenty of one cell lights, I will get testing asap. What causes a pacification layer, and is there a cause that is avoidable? Thanks again, I really appreciate it!

 

[m4a1usr]

There is some pretty good reading material (as well as calculators) on Passivation and Depassivation on the Spectrum Batteries web site. Well worth a stroll down information lane.

 

[SilverFox]

Hello Crazyeddiethefirst,

I guess I should learn how to spell...

The information provided by M4a1usr seems to explain what is going on.

The topic of passivation came up a few years back when BatteryStation was having some issues with their CR123 cells. They were manufactured in China and while they performed well they did not store well. This prompted Kevin to change manufacturers to Panasonic and the issue went away, for the most part.

At that time I ran across a white paper by Energizer stating about the same thing as is listed in the Electrochem article. In part that was that applying a load to the cell can burn off the passivation layer and restore the cell to like new condition, minus a small amount of capacity.

Digging deeper it seems that additives can be added to the electrolyte to retard this layer from forming and cheaper manufacturing processes may reduce costs by eliminating those additives. Also, impurities in the electrolyte chemicals can contribute to this problem.

The ZTS tester applies a load to the cell. Sometimes all it takes is 5 - 8 repeats of the test to burn off the passivation. Other times it takes a decent load. And still other times nothing helps. I just checked some BatteryStation mismatched cells from 2006. The started out at 80% on the ZTS in 2006 and I have been storing them to see what happens. When I tested I got 0% from these cells. After running them in a single cell incandescent light for a short time, they rebounded to 10%. There are a lot of variables involved and that makes it difficult to come up with a set way to try to recover the cells. I just end up using them in single cell lights.

After a number of tests and extensive evaluation I have decided that the ZTS gives me a heads up that something is going on. From there I usually subject those cells to a brief load and then rotate them to be used immediately. There are far fewer problems with quality cells, but sometimes they crop up.

Tom

 

[CoherentRays]

Wow, I only just discovered this thread because some kind soul resurrected it from obscurity in the past by necro posting to it. Like others, I add my thanks to HKJ and nominate it for a sticky.

Ed

 

[Bullzeyebill]

It's now a sticky.

Bill

 

[CoherentRays]

It's now a sticky.

Bill

Thank you, sir. :twothumbs

It will be much easier to find now when I'm trying to remember one of those more complex (to my mind anyway) techniques.

Ed

 

[Crazyeddiethefirst]

Hello Crazyeddiethefirst,

If you are up for an experiment...

Test your low cells and note the ZTS value associated with each cell that is in question.

Take a cell that showed low capacity on the ZTS and put it into a single cell light that draws reasonable current. If you don't have any, pick two of the cells that showed low capacity and put them into a multi cell light.

Next turn the light on for 15 - 30 seconds, then shut it off.

Take the cells out and let them rest for 30 minutes, then test them again with the ZTS tester.

If the value from the ZTS increases, there is a good chance the cells have developed a pacification layer inside. Once you burn this layer off the cells may perform as normal, at least in the short term.

Tom

Sorry for the delay, a few medical issues have kept me tied up. Well, I tried the testing as suggested, but no change if indeed it was caused by passivation. I tried using both LED & incandescent, in case the load was of consequence-no change.(there was no increase or decrease after application of load and recovery period). Any other ideas? Thanks!

 

[SilverFox]

Hello Crazyeddiethefirst,

Well...

Perhaps it is time to just move on.

Tom

 

[Crazyeddiethefirst]

I came to the same conclusion with one caveat-I am going to give Surefire a call and have a chat with them....thanks for your input!

 

[maniac78]

Very good guide! Could you someone explain how to measure the charging rate from a charger with the DMM ? It will be very helpful. Thanks

 

[CivilGear]

Wow great guide! Thanks for sharing!

 

[jackolantern]

Learned much from this thread! I read section on measuring power in flashlight. I don't have two meters and wonder what is method of measuring that with resistor. I did use resistor method to calculate current draw. Thanks for any reply.

 

[HKJ]

Learned much from this thread! I read section on measuring power in flashlight. I don't have two meters and wonder what is method of measuring that with resistor. I did use resistor method to calculate current draw. Thanks for any reply.

You simply replace the ammeter with a resistor (0.1ohm or less) and the move the voltmeter between the flashlight voltage and the voltage across the resistor.
I have started a new series of articles about multimeters, this series is more general (i.e. not flashlight specific), until now I have published two articles (thermocouplers & current measurement) and more is planned.

 

[MAD777]

...
I have started a new series of articles about multimeters, this series is more general (i.e. not flashlight specific), until now I have published two articles (thermocouplers & current measurement) and more is planned.

Thank you HKJ for your valuable contributions to this community!

 

[jackolantern]

Much thanks HKJ. You're extensive contributions here and on your website is invaluable. Will definitely look for your writings regarding meters.