capacity?

[susieqz]

hiyqa, guys.
@Jazzman helped me get my mc3000 doing what it should.
i'm charging batteries exactly like i want.
.7 charge to 4.05.
i know the IR too.
i can track IR over time.
does this tell me enow?
i can check capacity.
do i need to do that?
is that better data?
i think checking capacity isn't great for the battery.
it gets discharged all the way down, then filled to the brim.
i don't wanna do that unless you tell me i should.

 

[Rossum]

hiyqa, guys.

What IR values are you seeing? And what kind of batteries are you using?

Most batteries are rated to go 300-500 full depth cycles before they loose 20% of their capacity, so putting them through a full cycle to check capacity every once in a while shouldn't have a big effect on them.

 

[susieqz]

4 months old hg2s from 23 to 24
kinda disappointed in 30qs.
8 week olds are 24 to 25,
they get charged once/week.

haven't tested the green ones yet.

 

[Jazzman]

hiyqa, guys.
@Jazzman helped me get my mc3000 doing what it should.
i'm charging batteries exactly like i want.
.7 charge to 4.05.
i know the IR too.
i can track IR over time.
does this tell me enow?
i can check capacity.
do i need to do that?
is that better data?
i think checking capacity isn't great for the battery.
it gets discharged all the way down, then filled to the brim.
i don't wanna do that unless you tell me i should.

Don't overthink it @susieqz . With the exception of the initial IR reading on a new cell you don't really need to do any of those things unless it amuses you.

What I do is take an IR reading when I first get the battery in case I got a bad one. High IR would be a very good indicator. Just takes a second to do. Then Discharge>Charge the battery and read the IR at the end of the charge. There shouldn't be a big difference. There will be a little, but not that much. After that I don't need to check the IR again unless I notice the performance is dropping which is pretty easy to tell just by vaping. I might check at other times just because it amuses me or I'm bored, but it's not really needed.

With discharging, I discharge when it's new before putting a full charge on it. Probably not needed, but I do that anyway. Then I charge and use it. I won't do a discharge again unless performance drops off. Too time consuming, which doesn't amuse me.

I rely on @Mooch and all the battery testing he does. I couldn't begin to do the testing he does, and don't really want to. So I just buy batteries he has reviewed from places he recommends and with the initial IR check I'm pretty sure my batteries are OK.

It is interesting to do a couple of Charge>Discharge>Charge cycles and it's good to practice how so when you do suspect a battery going bad you'll know how to do it. If you want any tips on how not to spend so much time learning that, just let me know. I made a couple of stupid mistakes that cost me a lot of time. Most of it involves proper setting for safety features so the program doesn't stop part way through.

 

[susieqz]

yes. please, @Jazzman
i'd like to know the charge discharge thing.
i thot that was for capacity.
not so?
i also thot capacity was how you checked for fakes.
if IR will suffice, that's handy.
still, i wanna see capacity, at least once.
i'm very interested in this machine n i wanna become competant with it.

 

[Rossum]

i also thot capacity was how you checked for fakes.

Capacity and IR. In order to be confident in spotting fakes you really have to measure both. It's possible to make cheaper cells at just about any given capacity, but they will have higher IR than the real deal. Its also possible to make cheaper batteries with low IR, but the will be lacking in capacity.

One problem is that you need reference numbers. Capacity is of course specified by the manufacturer and everyone knows what it's supposed to be. IR usually is specified too, but you have to find a data sheet, and that's usually an AC value with a fairly broad acceptable range. The trouble with DC IR is that there's no standardized way to measure it, and variations in measuring techniques will produce different readings. How big a current pulse? How long?

Based on your numbers in post #3, this charger is measuring DC IR. I've posted a whole bunch of AC IR numbers (I'll find the thread later when I'm at my real computer) and have quite a few more I've been saving for a new thread.

Another thing to look for in a batch of new cells is consistency. Brand new genuine cells from a top-tier manufacturer should have minimal variation in both capacity and IR.

 

[susieqz]

thanks @Rossum.
i wan't aware that testing for fakes is so complicated.
is there a way to translate DC to AC numbers?
this is what i have to work with.

 

[bombastinator]

thanks @Rossum.
i wan't aware that testing for fakes is so complicated.
is there a way to translate DC to AC numbers?
this is what i have to work with.

Afaik, no. My charger won’t test AC resistance either, so it presents something of a problem.

 

[jandrew]

Afaik, no. My charger won’t test AC resistance either, so it presents something of a problem.

I thought most chargers only report AC ir, which is less useful and usually lower than DC ir -- DC ir measurement requires switching discharge rates and measuring voltage change (if I recall one of Mooch's posts correctly).

 

[bombastinator]

I thought most chargers only report AC ir, which is less useful and usually lower than DC ir -- DC ir measurement requires switching discharge rates and measuring voltage change (if I recall one of Mooch's posts correctly).

Might be true. I was told my charger couldn’t read ac because it has no ac connection. It runs through an ac-dc wall wart. I’d trust mooch before that guy though.

 

[RayofLight62]

When you measure the internal resistance of a battery with an AC load, we call it impedance measurement.

Basically, the measure of impedance is the measurement of the resistance at the standardised frequency of 1Khz.

Mathematically, resistance (DC) is a scalar value, while impedance (AC) is a vector. Both are measured in ohms, but impedance is described with a complex number, where the real part is the DC resistance, and the imaginary part is the reactive component.

You need a specialised test equipment to measure battery impedance.

As a note, good quality mods (and all quality electronic devices for that matter) have a bypass capacitor in parallel to the battery, so to avoid large AC components flowing thru the battery, and to comply with RFI regulations.

The latest mods I acquired include a battery IR meter - which is pretty accurate.

As it is truly simple to use, I found myself checking the battery IR quite often; but there isn't really much to see, as the IR value is stable (18 to 30 mohm - depending on which battery is installed), and all variations I spotted were caused by the battery cap not fully screwed in, or some dirt in the threads.

 

[Rossum]

I've posted a whole bunch of AC IR numbers (I'll find the thread later when I'm at my real computer)

Sorry about the delay. That was here:
Playing with a Vapcell YR1030 AC Resistance Tester

 

[jandrew]

Might be true. I was told my charger couldn’t read ac because it has no ac connection. It runs through an ac-dc wall wart. I’d trust mooch before that guy though.

I could certainly be recalling incorrectly (it is Wednesday after all -- anything can happen day). I do believe my zanflare C4 does AC ir -- and mine does not provide very consistent results, either across slots, or with reinsertions of the same battery in the same slot.

 

[susieqz]

well, mine is very consistant, in all slots.
so, it should give me good info, weither a/c or d/c.
i don't wanna buy more equipment.
rossum, this is strange, my charger shows that 30qs have higher IR
than hg2s.
your tests show the opposite.

 

[bombastinator]

I could certainly be recalling incorrectly (it is Wednesday after all -- anything can happen day). I do believe my zanflare C4 does AC ir -- and mine does not provide very consistent results, either across slots, or with reinsertions of the same battery in the same slot.

Wasn’t referring to you when I said “that guy”. Sorry. I was referring to the person that told me it wouldn’t be able to check ac IR. He said other things that weren’t very correct as well which lead me to be somewhat untrusting of his opinion. The one that leaps to mind is that there have been no actual changes in lithium batteries in the last ten years.

 

[Jazzman]

yes. please, @Jazzman
i'd like to know the charge discharge thing.
i thot that was for capacity.
not so?
i also thot capacity was how you checked for fakes.
if IR will suffice, that's handy.
still, i wanna see capacity, at least once.
i'm very interested in this machine n i wanna become competant with it.

You are correct @susieqz , discharging is the way to check capacity. I've talked to some people that swear that charging is the way to check capacity, but I don't agree. Discharging the batteries is what we do when we vape, so that's really the only metric that's interesting for us and how we know when a battery goes bad... it just doesn't last as long as it used to.

Before I can talk about discharge methods I need to know if you will be doing this with the computer interface or the charger buttons? Computer interface has many more options and can be automated with multiple steps chained together as well as the ability to save the data from the program cycle (which can easily be graphed in Excel). Saving the data on new batteries can be handy to reference if you think it's dying 6 months later and do another test. If you will be using the charger buttons are you in advanced mode? Let me know.

 

[susieqz]

@Jazzman , i'm trying to do everything right on the charger.
i've always been in advanced mode n i wanna save the programs.
i thot to get capacity you did a full discharge then charge in one program, but if there's an easier way that gives me accurate numbers, that would be great.
i don't wanna hurt the batteries tho.

 

[Mooch]

Sorry about the delay. That was here:
Playing with a Vapcell YR1030 AC Resistance Tester

This is a great little unit, especially considering its price. It was only off by about 10% from a BK Precision Battery Analyzer that costs far, far more. A great deal.