Simple Battery Tests

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Cochise334ever
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Simple Battery Tests

I am not scientific,I’m analytical and just go by my experience. I’m not sure the exact answer to my title. But what prompted it is this.

I have brand new batteries, GA unprotected button top. After resting overnight they lost 0.04v. Not a lot but when I compare it to batteries that I have that are a year and a half old up to five and a half years and they’re resting voltage is better it makes me think as to what is the cause?

I know through experience once my resting voltages are 4.10v, 4.11v, the batteries are older, the runtime is less the capacity is less and no doubt they’re degrading which is natural after a period of time.

First thing to note is that the healthy batteries always come out of my S4 Plus at 4.19 volts. Never charges to 4.20 volts. That’s according to my DMM. That 100th of a volt makes a difference to my type A personality.

They came off the charger at 4.19 volts. All four of them. The resting voltage for the Brand New GA unprotected button top are 4.15v after 15 hours.

Vapcell M11 and G53 are 18 months old. The 2 x M11 have a hundred Cycles and the 2 X G53 have 140 cycles. They are used every 3 to 4 days. They’re resting voltages are rarely 4.17 volts, usually 4.18 and sometimes 4.19 volts.

And then you have the most impressive because they’re much older. 2 X VTC5A and 2 X VTC5D are five and a half years old. They have around 300 cycles. I just started using them again because I’m getting two hikes a day in early AM and PM.I am starting to use some of my older lights.

I have left these batteries alone for months and they were still at 4.17 volts. Once in awhile 4.16 volts. Now that I’m using them again every few days they’re usually at 4.18 volts or 4.17 volts

Am I driving you guys nuts yet?!

I do know this with some sets of batteries, through experience, when one starts out with a lower resting voltage they seem to degrade quicker.

I still believe the GA’s are going to serve me well, but Wonder why,,,,,, question is below.

I have the mentality that I always want to know the answer.

So after my summary, will be the primary question behind this thread.

To summarize:Resting Voltages.

Brand new GA UP BT. 4.15V after 15 hours.

M11 18 months old 100 Cycles. Resting voltage 4.18 volts.

Vapcell G53. 18 months old. 140 Cycles. Average 4.18 volts.

VTC5A and VTC5D. 5 and 1/2 years old 300 plus Cycles. average 4.17 volts.

Why are batteries that are one and a half to 5 and 1/2 years old with anywhere from 100 to 300 Cycles have a better resting voltage than a brand new battery?

I believe the chemistry for all those batteries are very similar or the same. And I was told by the hometown dealer that these Hi drain batteries will degrade quicker. That is yet to be determined in this case. What is determined is the older and used batteries have a better resting voltage than a brand new one.

Happy Thanksgiving!

To admit is to acknowledge.To Accept is to take action.

Edited by: Cochise334ever on 11/27/2022 - 09:30
kennybobby
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Your intuition is good; based upon your measurements i would agree that there is a defect in the new cells.

The old cells were built with better quality, either in the materials or the processes.

It requires clean room facilities to make precision separator membranes and to assemble cells. Any impurities can cause defects in the electrode layers and the electrolyte. A particle of dirt can cause a high impedance short between the layers. There are numerous reasons and ways for a defect to occur in a cell.

Have you tried to do a capacity test of a new cell to compare with the advertised or specified value? That would provide additional clues about the quality of that cell. Also the same with an internal resistance test?

The new cells may still be usable if the self discharge is not too excessive, but good cells will have less than 1% per month self discharge.

You could try some high current discharges and a few cycles of discharge and charging to see if it “wears in” and becomes more stable. A dust particle might burn itself out and remove the short.

If you have more than one cell, leave one as a reference and just monitor its daily decay for a couple of weeks while you mess around with test the others.

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

Cochise334ever
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^^^

Sorry I should have included this and mentioned that the capacity was fine.

My 4 cell median=3290mAh

HKJ= 3264mAh

If the GA’s stay stable and don’t drop anymore voltage, I think they’ll be okay.

You wouldn’t think that Vapcell are better than Panasonic/Sanyo. Like with everything else, there can be exceptions.

My VTC5A and VTC5D are great cells. I wish they were more available and cheap like they used to be.

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Correllux
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First question….what is the resolution and accuracy of your meter at hundredths? Most meters don’t do so well there and/or because of their accuracy range just aren’t precisely repeatable (same goes for chargers even more so).

If you’re most focused on degradation then you really need to invest in a good setup to measure internal resistance (comparing to an as-new baseline for your cells). That will tell you more than voltage, and sooner. Chargers (any of them) are not reliable for IR measurements.

Kindly, obsessing over hundredths is not important but if you really want to investigate it then be sure your measuring equipment is capable of telling the truth. Generally you can just be comfortable watching 0.05 with a normally-decent meter and call it good, and actually for our purposes tenths are just fine, imho. What’s important is not so much where they settle, but IF they settle, and sometimes with degraded cells how quickly they drop. Obviously these are very small numbers when new/in good health but you don’t usually see them change a bunch until you’ve had many cycles on the cells, provided that they haven’t been grossly “abused” in one way or another.

I don’t know if the current China-factory Panny cells are that much different than the previous Japan cells but it seems like Mooch re-tested the GA and found they were actually better than Japan cells from a few years prior…if it wasn’t Mooch is was somebody else. lol. Whoever that was had three tests on them and they were largely the same, just very small differences. It’s a great cell, holds its own against others. I have a couple that are just reserved for UV lights since they hold their voltage just a smidge better at lower current draw than 35E/VTC6/M35A/MJ1 and for the cranky voltage demands of UV emitters it can help just a little.

Cochise334ever
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Correllux wrote:
First question….what is the resolution and accuracy of your meter at hundredths? Most meters don’t do so well there and/or because of their accuracy range just aren’t precisely repeatable (same goes for chargers even more so).

If you’re most focused on degradation then you really need to invest in a good setup to measure internal resistance (comparing to an as-new baseline for your cells). That will tell you more than voltage, and sooner. Chargers (any of them) are not reliable for IR measurements.

Kindly, obsessing over hundredths is not important but if you really want to investigate it then be sure your measuring equipment is capable of telling the truth. Generally you can just be comfortable watching 0.05 with a normally-decent meter and call it good, and actually for our purposes tenths are just fine, imho. What’s important is not so much where they settle, but IF they settle, and sometimes with degraded cells how quickly they drop. Obviously these are very small numbers when new/in good health but you don’t usually see them change a bunch until you’ve had many cycles on the cells, provided that they haven’t been grossly “abused” in one way or another.

I don’t know if the current China-factory Panny cells are that much different than the previous Japan cells but it seems like Mooch re-tested the GA and found they were actually better than Japan cells from a few years prior…if it wasn’t Mooch is was somebody else. lol. Whoever that was had three tests on them and they were largely the same, just very small differences. It’s a great cell, holds its own against others. I have a couple that are just reserved for UV lights since they hold their voltage just a smidge better at lower current draw than 35E/VTC6/M35A/MJ1 and for the cranky voltage demands of UV emitters it can help just a little.

I do not know the resolution and accuracy.

I do know that I use the same meter for all these batteries so there’s consistency there. That’s all I can ask for and that’s what I go by. Simply if it’s off by a little bit for battery A then it is going to be off by a little bit for battery B.

When you have several batteries consistently measured at the same voltage and then you get a new one that is lower than that. It makes me curious and it’s something that I would question.

This is redundant but I want to make my point clear. You have batteries that are much older and have a higher resting voltage than
BRAND NEW ones. Now if the batteries are the same age and I was obsessing about a few hundreds of a volt I could see that but they’re not. Brand new ones and older ones.

I see nothing wrong with my thinking and questioning of this very important matter!

To admit is to acknowledge.To Accept is to take action.

Correllux
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Ok. Well. Maybe cycle them a couple times at datasheet currents and see what they do afterwards. 0.2C, generally, both directions, rest periods not so important.

I know you’re ok with your thinking (I’m the same way actually), I’m just saying that repeatability may not be there with the measuring equipment…that is a related but separate issue from resolution and accuracy. Many meters simply don’t provide what you’re asking for here and that can’t be wished away…kind of like how some people are wanting the Opple devices to be something more than they are capable of being. You don’t need to buy a new or more expensive meter necessarily, maybe just relax your expectations on hundredths (or maybe not…you don’t know its specs and haven’t said the make/model, so maybe it’s just fine).

Oli
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Batteries can do some funky things when they’re brand new. So your observations prove nothing. So as stated above, cycle them a few times. The bigger issue is that lithium ion batteries should not be charged to full capacity and then just left to sit at full voltage. So your obsession and measuring procedures are doing more harm than good. Apple sells 200 million phones per year. They have put settings in place (in recent years) to help consumers avoid charging to 100% until they’re ready to use the phone. The main goal is to avoid batteries being left at 100% charge through most of the night while people are sleeping. Most EV manufacturers have standard settings to charge the battery to 80 and 90%. You can override this if you know you’re going to need extra capacity for a specific trip. But to get the maximum number of years of life out of the battery they should not be charged to 100%.

You can't compare the big flashlight in the sky to the little flashlight in your hand.

Oli
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This subject has been covered before and there are plenty that would chime in.
“I don’t care if I’m going to get 10 or 50% less cycle life”. “Batteries are cheap and I don’t need to keep them 10 years”. “I keep them full because I want to be able to use them when I need them or in an emergency”. There’s no question that they are more unstable and dangerous when “fully” charged. Plenty of people store gasoline containers and propane tanks in an attached garage or basement.

You can't compare the big flashlight in the sky to the little flashlight in your hand.

Cochise334ever
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Oli wrote:
Batteries can do some funky things when they’re brand new. So your observations prove nothing. So as stated above, cycle them a few times. The bigger issue is that lithium ion batteries should not be charged to full capacity and then just left to sit at full voltage. So your obsession and measuring procedures are doing more harm than good. Apple sells 200 million phones per year. They have put settings in place (in recent years) to help consumers avoid charging to 100% until they’re ready to use the phone. The main goal is to avoid batteries being left at 100% charge through most of the night while people are sleeping. Most EV manufacturers have standard settings to charge the battery to 80 and 90%. You can override this if you know you’re going to need extra capacity for a specific trip. But to get the maximum number of years of life out of the battery they should not be charged to 100%.

You misinterpret, misunderstand and are quick to judge.

Where did I say that I was storing them at full capacity? Letting them sit full for several days is not going to harm them. I’ve done that for many years. I have some NCR 18650A 3100 batteries that are nine and a half years old. Treated the same way.

EDIT.

For 14 years I’ve been rotating my flashlights on my nightly hikes. That means that for 4,5 6 days and sometimes longer they are at full capacity until they get used.

I have lasted anywhere from two and a half years to 9 1/2 years. Depending on the use and the power of the flashlight.

In any event they don’t cost that much. Cost had no Factor at all in my curiosity between the resting voltage differences of brand new batteries and ones that were used for years.

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Oli
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Cochise334ever wrote:

Where did I say that I was storing them at full capacity? Letting them sit full for several days is not going to harm them.

You clearly state that you left two sets for months and measured 4.17v. I’m not going to go back and forth. You do what you want. Your observations prove nothing.

You can't compare the big flashlight in the sky to the little flashlight in your hand.

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Oli wrote:
Cochise334ever wrote:

Where did I say that I was storing them at full capacity? Letting them sit full for several days is not going to harm them.

You clearly state that you left two sets for months and measured 4.17v. I’m not going to go back and forth. You do what you want. Your observations prove nothing.

Yes I clearly state that my older VTC5A and VTC5D we’re fully charged sometimes for a few months and not used.

Why would I put them in storage? They’re old batteries and they’ll be used like they’re being used a lot now. They weren’t STORED! A misunderstanding by you, misinterpretation if you will. I don’t store batteries fully charged. They are stored at 3.5 volts to 3.6 volts. Some lay around longer than others and then they’re ready when I want to use them.

It goes to show you that, unintentionally, my older batteries like the vtc5a, vtc5d,can still work well and hold their resting voltages if they’re fully charged for a week, 3 weeks whatever. Maybe they lost a couple Cycles, who cares!They are Older.

I have to add the first four and a half or five years of their life they were used consistently and taking care of and not abused.

So why are you criticizing me for leaving a few sets of OLD batteries fully charged so they’re ready for when I want to use them?

Read your posts. You contradict yourself. You do the same thing with your batteries because you want them ready and they’re not that expensive yet when I do it you preach to me and criticize and misunderstand.

Did they get ruined? They’re six and a half years old and they still work well.

It’s best that you don’t want to go back and forth. Because I could pick apart your contradictions, misinterpretation, misunderstanding and approach.

Have a good day

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chops728
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My Sony cells always seemed a notch above others in every way, especially Longevity. That settling of the voltage might just be the characteristic of those cells, I would be more concerned if they keep dropping the longer they sit. I have several EVO 14500 cells and for some reason they always settle around 4.13v. But that’s it, they’ll stay there for quite a long time (months)

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That’s a good observation; slight differences in electrolyte composition and electrode materials can affect the “full” resting voltage.

Once all the lithium ions have intercalcated into the electrode matrix then there is no room for anymore; trying to push them in will cause heating and damage. It’s like a brawl that breaks out in a crowded tavern when all the seats at the bar are filled and they announce free beer.

The general charging protocol of CC/CV with cutoff when current drops to .1C was designed to fill most cells without regard to composition.

But if you know that the full resting voltage is less than 4.2V then there is no need to go that high during CV.

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

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chops728 wrote:
My Sony cells always seemed a notch above others in every way, especially Longevity.

I agree 100%. I just ordered 8 X VTC5D from 18650 battery Black Friday sale. Only $4.85. My experience with those and their relatives(VTC5/VTC5A), is that not only do they perform well, they do it for a long time.

According to the gentleman,Stephen, who I spoke to on the phone they got them last September and it’s probably the last batch that they’ll get and may be the last ones Murata makes.

Molicels seem the start degrading noticeably and rapidly after 18 months, 2 years at the most. They are good for a while then they begin to lose capacity quickly.

Sony/Murata as I used examples in the beginning of my op continue to work well. Capacity is still good and the resting voltage drop is minimal even after 5 and 1/2 years.

My 30q seem to work very well also after several years.

I ordered several Samsung 50S on sale also. I look forward to getting them Monday. I’m sure they’ll do better then my P42A.More capacity and according to mooch slightly better at 10 amp and 20 amp and about the same at 30 amp. We’ll see how they do in the degrading Department.

I think it was a thread on here and what mooch may have said. Because of their high capacity and their ability to push amps pretty well, something has to give and that may be the cycle life. Time will tell.

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Cochise334ever
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Always been satisfied with my 30Q’s.

Purchase November 3rd 2020. Four slot medium was 3003mAh.

Today, November 26th 2022. Little more than 2 years later and 195 cycles.

Four slot median is 2705mAh. Only 10% capacity loss. Thumbs Up

Compared to my Molicel P42A which Had 150 Cycles and a 15% capacity loss in just 15 months. Facepalm

I like numbers as you can see. This isn’t about money. Cells are relatively cheap ,but I like to get the best ones. Who wouldn’t?

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I got my Samsung 50S today. Thumbs Up

I’m satisfied with the capacity. I believe mooch discharges down to 2.5 volts.

My Opus goes down to 2.8 volts.

My 3 cell median is 4884mAh

Mooch test 1.

July of 2021=5119mAh. Two cell median

Test#2 on 8.10.22= 5060mAh median. Two cells.

I’m using them in my modified K1.

I hope the runtime and Longevity is better than my P42A.

The light is so powerful after 10 minutes of combined Max output the voltage is around 3.48 to 3.55 volts depending on the battery.

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Cochise334ever
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Very satisfied with the run time using the 50S in my K1.

I expected better run time and I got 15% more runtime than the 40T or P42A.
As mentioned prior,
the light only gets 10 minutes of cumulative Max output.

The low voltage warning came on at 7 and 1/2 minutes for 40T and the P42A.

9 minutes and 7 Seconds for the 50S. Cool

With that said you’re not running the light for 10 straight minutes. It would get way too high even if it was 10° Fahrenheit out. So this battery between Max output and cooling light off will last me 15 to 18 minutes. I’m sure you’re all very excited about all this!

I’m so excited about it I bought three more 50S last evening before 18650 battery stores Cyber Monday was finished. Thumbs Up

Oh, yeahh.. the only question remains, and time will tell is the longevity of this battery and how fast it will degrade compared to the others.

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Limsup
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I have two 18350 cells from Keepower (UH1835P) that self discharge very fast. One lost 0.20v from full in 26 days and the other in 20 days. I think my cells are defective.

I would monitor if the voltages are dropping for a week. If there is significantly high self-discharge, then it would not settle. At least my Keepower cells do not.

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^^^

That is pretty rapid. I remember I had this older, about 2 years old, Orbtronic 26650. Supposedly had that popular PLB 5500mAh cell in it.

I still have the stats on it somewhere but from a full charge it was basically down to 3.6 volts in less than 1 month.

How old are your batteries?

EDIT.

I found the info. It went from 4.23 volts on September 13th to 3.63 volts on October 26th. So that was about a month and a half it lost 0.60 volts.

Not as rapid as self-discharge as I thought but fast enough to make the battery useless and get recycled. Yours is in a similar position almost as fast as a self-discharge. I would definitely get new ones if you haven’t already they’re not going to all of a sudden get better.

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Limsup
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The keepowers I have is purchased on May 2021. And they did not see much use. When I first used it, I had a feeling that battery levels go down way faster than what I am used to. I thought it may be because of lower capacity (1200mAh) than 18650 cells that I normally use. I recently decided to investigate it and decided to measure voltage every day after fully charging them and I got the numbers. Interestingly battery capacity seems to be within spec, despite the high self discharge rate.

Had I known about it, I would have complained to the AliEx seller, but so many days have passed… My 18350 light is not used a lot, so I charge them once in a while. Moreover, I couldn’t find reputable cell brand for 18350 to spend my money on.

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I still have these aspire batteries. I used them for about 3 years and their capacity was still good. This test was when they were brand new. That was the best 18350. Mine were the original ones that had 1,300 milliamps written on it. The ones after that which I believe were the same exact thing had 1100 milliamps on it.

When I got the Vapecell M11’s I put the Aspire 18350 in storage. I recall their capacity was as good as brand new m11s!

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Cochise334ever
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Almost 3 years old.

About 20 months old VS. KP!!

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Limsup
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Wow! Seems like you accumulated a lot of capacity data! Thank you for sharing the information. I think I will look into Vapcell M11 and Aspire.

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Here it is.

The Aspire were 4 years old! They had 90% of the capacity of brand new cells!

It is a shame that they stopped making that cell. Facepalm

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Limsup wrote:
Wow! Seems like you accumulated a lot of capacity data! Thank you for sharing the information. I think I will look into Vapcell M11 and Aspire.

Yes I like numbers. For 12 years I have kept track of everything. Battery cycles, capacity tests, run times ect..

That’s what happens when you’re a flashaholic and have a type A personality. They seem to go together.

As I mentioned they don’t produce that Aspire cell anymore. The M11 is doing okay I’ve had it about a year and a half.

To admit is to acknowledge.To Accept is to take action.