ZTS tester - what is this pulse tech ?

[zband]

I received my ZTS tester a couple of days ago and its done what it was suppose to do so far. That has helped me send a bunch of alkaline cells to the recycle center.

I was wondering if someone could explain to me this "pulse tech" that it uses to determine the charge left in my batteries.

1. I understand as Lithium ion batteries age they lose their ability to hold their original capacity of charge. For example, my ipod used to be able to play for hours on a full charge (according to its own battery indicator), now despite the the ipod's indicator saying its fully charged it cant seem to last as long. It seems that its capacity has decreased, and I assume that the future of my 18650 cells are going to be similar. will the zts tester show this decreased capacity as the battery ages or will it state that an older 18650 is "fully charged" with this pulse tech?

 

[Exit32]

ZTS battery testers applied a "Pulse Load" to the battery being tested. I suspect this is done to remove the surface charge from a resting battery and stress the battery a little before it's tested.

You didn't say which ZTS tester you own. The larger ZTS Multi-Battery Tester is capable of testing 3.6-volt lithium-ion rechargable batteries. The more common ZTS Mini Multi-Battery Tester will not test 3.6-volt rechargables like your 18650 cells.

I own the smaller ZTS Mini MBT, so I don't know if the larger ZTS tester is capable of determining reduced capacity in an older, fully charged lithium-ion cell. I hope someone will be able to answer this, because I am curious about this too.

 

[zband]

You didn't say which ZTS tester you own. The larger ZTS Multi-Battery Tester is capable of testing 3.6-volt lithium-ion rechargable batteries. The more common ZTS Mini Multi-Battery Tester will not test 3.6-volt rechargables like your 18650 cells.

Sorry I own the big one , the mtb-1

With the press release on "pulse load tech" I'm throughly getting confused about the ZTS being able to estimate capacity in the battery right now (even though it could be old and thus lost its original higher capacity) versus what it was new and its "state of charge"...

 

[SilverFox]

Hello Zband,

The ZTS tester pulses a load on the cell and notes the voltage of the cell under that load. It then compares that information with what is stored in its look up table to give you an idea of the state of charge of the cell. The pulse load takes very little capacity from the cell under test.

The look up table has been developed by a series of tests done by ZTS on a variety of cells. Not all brands have been tested, and their target use may be different from your use, so there are some differences in the results.

For example... If you are using CR123 cells in a SureFire M6, you may find that the ZTS displays a lot of capacity left after the M6 has depleted the cells. I believe that the ZTS is thinking that the CR123 cells will be used in a typical camera.

While it is not very accurate, it is very consistent. This allows you match cells for multi cell applications, and once you have used it for awhile in your applications, you can get a very good idea of where you stand based on its results.

Tom

 

[abvidledUK]

I believe that the ZTS is thinking that the CR123 cells will be used in a typical camera.

Tom

It would be nice if they could add the capability to accurately test high discharged cells, as used in torches.

 

[zband]

I emailed ZTS and received a quick response!


"...Thank you for your email. Regarding the Li-Ion rechargeable batteries, the MBT-1 will indicate remaining capacity or State-of-Charge. For example, a new/good 18650 that is simply somewhat discharged may test 40%. That same battery should test at 100% when fully charged (if it is indeed good). A battery that has aged or deteriorated and is no longer capable of taking a full charge, will test lower even after charging (i.e 60% or less). In either case the tester will indicate the battery's remaining capacity. Using that test result to determine battery condition (loss of capacity) requires knowledge of when the battery was last charged...."


Wow, I had no idea the MTB could do that!

EDIT : I emailed Dave at ZTS to confirm my question, which he did.

 

[Zenster]

A battery that has aged or deteriorated and is no longer capable of taking a full charge, will test lower even after charging (i.e 60% or less). In either case the tester will indicate the battery's remaining capacity. Using that test result to determine battery condition (loss of capacity) requires knowledge of when the battery was last charged...."
Wow, I had no idea the MTB could do that!

It's been said by many that it isn't necessary to put a load on a LiIon battery to test it's condition, but the explanation by the company as you note is exactly why it's still a good idea.

IF you know your battery is healthy and you just want to know it's general state of charge, then putting a load on it isn't necessary. A simple Multi-Meter voltage reading will give you what you want.
However, that doesn't test the battery's condition, only it's "apparent" state of charge.

But putting a load on a battery every time you check it is a good idea because you'll be able to find out much sooner if the battery is on the brink of failure.
You may get a similar loaded reading for a couple of years or so right after a full charge, but when it begins reading just a little off from it's just-full-charged norm, you know it's just beginning to fail.

 

[zband]

It's been said by many that it isn't necessary to put a load on a LiIon battery to test it's condition, but the explanation by the company as you note is exactly why it's still a good idea.


But putting a load on a battery every time you check it is a good idea because you'll be able to find out much sooner if the battery is on the brink of failure.
You may get a similar loaded reading for a couple of years or so right after a full charge, but when it begins reading just a little off from it's just-full-charged norm, you know it's just beginning to fail.

Tested my rc123 cell MM showed 3.99V but the ZTS indicated 40%. Its an older abused cell.

 

[louie]

Try doing 10-20 ZTS tests in a row - I'd be interested in your results. On some RCR123 cells, I'm seeing a drastic ZTS reading drop.

 

[zband]

Interesting, I just did 20 tests like you suggested and it dropped from 40% (first couple) to 10% afterwards I checked MM its voltage dropped to 3.91.

Maybe the ZTS sucked the last bits of charge outta it?

 

[Meterman]

I'm just running a test on the older model of the ZTS MBT-1 (with only 8 places for different batteries instead of 10 at the newer model) with an eneloop AA. The result looks a bit confusing, because the percentage shown in the beginning is too low and at the end it's too high.

Method used: full battery discharged at 0.2C in steps of 400mAh each and then ZTS-tested in between directly and after a pause of half an hour.

Results will be shown when cell is empty.

Any better proposals?

Wulf

 

[Meterman]

Testing results ZTS MBT-1 / eneloop AA:

discharged 400mAh, tested immediately: 40/60/60; + 30min: 60/60/60
discharged 800mAh, tested immediately: 40/40/40; + 30min: 60/60/60
discharged 1200mAh, tested immediately: 40/40/40; + 30min: 60/60/60
discharged 1600mAh, tested immediately: 20/20/20; + 30min: 40/40/40
discharged 1979mAh, tested immediately: 0/ 0/ 0; + 30min: 10/10/ 0

These results are not that reliable. Ideal values should have been 80 - 60 - 40 - 20 - 0.

(OK, OK, the empty cell is indicated pretty precisely, but this can't be all! )

Any idea, how to come to reasonable results when using the MBT-1?

Wulf

 

[SilverFox]

Hello Wulf,

Eneloop cells hold a higher voltage than other cells, and were not part of the database used for the look up table used by the ZTS testers. It looks like you got reasonable results with the immediate tests, but the tester was thrown off after the cells had rested for awhile.

Tom

 

[Meterman]

Hello Tom,

thanks for your explanation concerning the look up table, that's plausible.

I use dozens of eneloops since they are in the market and know their characteristics, but the first two lines of the test are disappointing though.

Some day I may offer up some primaries to see what I can expect from the MBT-1 in that sector.


Wulf

 

[louie]

Interesting, I just did 20 tests like you suggested and it dropped from 40% (first couple) to 10% afterwards I checked MM its voltage dropped to 3.91.

Maybe the ZTS sucked the last bits of charge outta it?

I've seen similar results with RCR123 - but then doing a runtime test gives me reduced, but much better than 10 or 20% indicated by the ZTS.

The ZTS pulse draw is not a whole lot of current IIRC. I conjecture it has something to do with internal resistance of the protection circuit or cell itself.

A couple of AW cells I've had for a few months aren't showing this phenomenon.

 

[Monocrom]

For example... If you are using CR123 cells in a SureFire M6, you may find that the ZTS displays a lot of capacity left after the M6 has depleted the cells. I believe that the ZTS is thinking that the CR123 cells will be used in a typical camera.

While it is not very accurate, it is very consistent. This allows you match cells for multi cell applications, and once you have used it for awhile in your applications, you can get a very good idea of where you stand based on its results.

Tom

Thanks Tom. I really wish I had seen this thread before buying my ZTS MBT-1. I think I could have lived without it. Just guess I'll have to count the minutes on my M6 after switching it on. :shakehead