Lithium Ion memory batteries Voltage?

[CalG]

I've got a pair of automated equipment that makes use of GE Fanuc PLCs.
The logic memory retention batteries are replaceable (BR-2/3A) Nominal 3 Volt
I just pulled one and replaced it with a spare that has been on the shelf for this purpose.

The pulled battery was placed in service in 2006. (amazing when I consider it is still doing the job!)

I also have an "old battery" of unknown history, but is likely the one replaced in '06.

Any way

The battery just removed displays a measured voltage of 3.37 volts
I should have measured the "new" replacement battery, but I didn't. and it's a pain to replace. "big fingers and bad eyes)

the "very old battery" measured 3V when first compared last week .

I did a "recharge" using my bench supply.
1 Hour at ~4.2 V constant current at 150mv. and then 2 hours "saturation charge" at Constant voltage of 4.12 v Charge current falling to about 80 mv at the end)
(The batteries have a warning label "Do NOT Recharge!" But hey, where is the fun in that? ;-)

Now, that old battery measure 3.37 volts after sitting on the bench for 24 hours . Just the same as the battery recently removed.

Question.??

Are both batteries still "GOOD"?

How can one know?


And sure, for $12 , JUST BUY NEW ONES! but that is not the question.

I have new ones. ;-)

 

[technocrat]

you need to put a load on them, say 100mA which would be a 27 or 33 ohm resistor. The old battery will drop in voltage much faster than a new one.

 

[CalG]

you need to put a load on them, say 100mA which would be a 27 or 33 ohm resistor. The old battery will drop in voltage much faster than a new one.

And then?

Charge 'em up once more ? Keeping the better for "emergency use"?

I'm all about ampacity, but it's a tough game. Trying not to kill the patient and all that sort of stuff.

Without a detailed comparison curve of a fresh new item, "Faster" has no reference.

eta

"Faster" also begs the question. The old battery was in service uninterrupted since 2006. What sort of "service life decline" should one expect? It sure must not take much to hold a small amount of machine memory.

But when I put the equipment in service, the memory WAS dead. I have the backup on a hard disc, but I would rather not reload it ever again.

 

[technocrat]

And then?

Charge 'em up once more ? Keeping the better for "emergency use"?

I'm all about ampacity, but it's a tough game. Trying not to kill the patient and all that sort of stuff.

Without a detailed comparison curve of a fresh new item, "Faster" has no reference.

yes it does, good batteries will rapidly return to their resting voltage after their test, faulty batteries will remain at a much lower voltage. Batteries die when their internal chemistry fails, this is how you test them.

You are right that memory backup only needs a very small current and they type of batteries chosen for this application usually have very low self discharge. You may find that the battery that has been in service will be in better condition than the one on the shelf as it's internal chemistry is being exercised with charge/discharge cycles. 15 years is a long time, probably more luck than design expectation. You don't see much of service life decline, they just stop holding charge one day when they wear out.

Your question was:
Question.??

Are both batteries still "GOOD"?

How can one know?

 

[crickets]

Here is one datasheet for these cells https://biz.maxell.com/en/primary_batteries/CR_17e.pdf
What I'm trying to figure out regarding OP - has he violated safety rule #1, #2 or both ?

 

[CalG]

yes it does, good batteries will rapidly return to their resting voltage after their test, faulty batteries will remain at a much lower voltage. Batteries die when their internal chemistry fails, this is how you test them.

You are right that memory backup only needs a very small current and they type of batteries chosen for this application usually have very low self discharge. You may find that the battery that has been in service will be in better condition than the one on the shelf as it's internal chemistry is being exercised with charge/discharge cycles. 15 years is a long time, probably more luck than design expectation. You don't see much of service life decline, they just stop holding charge one day when they wear out.

Your question was:
Question.??

Are both batteries still "GOOD"?

How can one know?

So..

As A test. If a 33 ohm resister is placed across the terminals for say a draw down from 3.36 to 2.8V.

The "better" battery should see a elf revitalization back to 3.3 Volts after a short time period?
While any "aged" battery" will show a lower value, or may not return to even 3V, the nominal value?
I believe the voltage value for a "dead" Lithium Ion cell is 2.2 V .

This single cell is used in example. There are so MANY Li-Ion cells around these days.
Power hand tools, boot heaters, bicycle power units, yard equipment, Tesla Cars. The list goes on.

It would be nice to "now when to hold 'em, and know when to fold them."
Know when to walk away, Know when to run!

A single cell is just that.

 

[CalG]

Here is one datasheet for these cells https://biz.maxell.com/en/primary_batteries/CR_17e.pdf
What I'm trying to figure out regarding OP - has he violated safety rule #1, #2 or both ?

Certainly the FIRST!

but the last scares me the most!

"Never touch the battery electrodes.
Do not allow the battery electrodes to come in contact with your skin
or fingers. Otherwise, the moisture from your skin could cause a
discharge of the battery, which could produce certain ch blah blah blah!" ;-)

But I protest.

For a fool PERSISTING IN FOLLY, gains WISDOM.

Challenges arise for the "do nothings" every day!

Why would both batteries display such SIMILAR rest voltages after being so unsafely abused? (other than chemistry that is;-)"

Perhaps the larger question is "What differentiates a chargeable Li-Ion battery from one that is NOT rechargeable"?

Is it the assumption that the typical industrial consumer does not have an adequate bench power supply and an accurate volt meter and amp meter?

Or is it an expectation that in service, the damn things will dry out before they fail to produce voltage, and recharging won't put the magic juices back in?

 

[crickets]

Certainly the FIRST!

But I protest.

For a fool PERSISTING IN FOLLY, gains WISDOM.

Challenges arise for the "do nothings" every day!

Either way, I was wondering how did you come up with 4+ charging voltage. These cells are supposed to have OCV of about 3.2

 

[technocrat]

Here is one datasheet for these cells https://biz.maxell.com/en/primary_batteries/CR_17e.pdf
What I'm trying to figure out regarding OP - has he violated safety rule #1, #2 or both ?

Most non-rechargeable batteries will take some charge. Sometimes they lose all capacity, sometimes they explode, sometimes they work for a while and sometimes a long time. You just have to be ready for any of the outcomes.

I can't comment on rule #1

 

[technocrat]

So..

As A test. If a 33 ohm resister is placed across the terminals for say a draw down from 3.36 to 2.8V.

The "better" battery should see a elf revitalization back to 3.3 Volts after a short time period?
While any "aged" battery" will show a lower value, or may not return to even 3V, the nominal value?
I believe the voltage value for a "dead" Lithium Ion cell is 2.2 V .

This single cell is used in example. There are so MANY Li-Ion cells around these days.
Power hand tools, boot heaters, bicycle power units, yard equipment, Tesla Cars. The list goes on.

It would be nice to "now when to hold 'em, and know when to fold them."
Know when to walk away, Know when to run!

A single cell is just that.

yes, the drop under load and the rebound tell you a lot. A dead cell given a zap up to 3.3 volts will drop to 2v under load and stay there. A brand new one will be at 3.3v, dip and rebound quickly. Rechargables lose a bit of capacity with each charge but perform in a similar way.

Multi cell you cannot tell, you have to test each cell individually, and packs are best with matched batteries. Their are battery analysers which do the discharge / rebound test plus an internal database of charge/discharge curves. If you had a big investment in batteries they would be worth having. With most things being throw-away, we don't even have many options for pulling battery packs apart and making one good one out of two.

 

[CalG]

Either way, I was wondering how did you come up with 4+ charging voltage. These cells are supposed to have OCV of about 3.2

Li-Ion literature. It "appears" that the nominal voltage is quite a bit less than "full Charge".

The 48 volt battery pack for the bicycle is fully charged at 54 V. 48 V being it's best "storage Voltage". Above which, life is shortened.

Much as a 12V Pb acid wet cell charging at 14.5, to overcome internal resistance.

 

[CalG]

Multi cell you cannot tell, you have to test each cell individually, and packs are best with matched batteries. Their are battery analysers which do the discharge / rebound test plus an internal database of charge/discharge curves. If you had a big investment in batteries they would be worth having. With most things being throw-away, we don't even have many options for pulling battery packs apart and making one good one out of two.

Your last paragraph is EXACTLY WHY I used the single cell in my question. ;-)

 

[crickets]

Li-Ion literature. It "appears" that the nominal voltage is quite a bit less than "full Charge".

The 48 volt battery pack for the bicycle is fully charged at 54 V. 48 V being it's best "storage Voltage". Above which, life is shortened.

Much as a 12V Pb acid wet cell charging at 14.5, to overcome internal resistance.

Okay, so you're a bit confused. The nominal voltage (as well as the max voltage of a rechargeable cell) is a product of cell's chemistry. Most common Lithium Ion cells (LiPo, NCA, NMC) have the nominal voltage of 3.7v, with maximum voltage being 4.2v. The bicycle cells you're referring to are LFP cells with 3.2v nominal and 3.65V max.

Then, Lead-Acid batteries behave completely differently than rechargeable Lithium batteries, so comparing to them is pointless.

Finally, the cells you've got are PRIMARY cells, for which max voltage is typically not specified since they're not rechargeable, but pushing them like 25% over their OCV seems like a strange move.

 

[CalG]

Okay, so you're a bit confused. The nominal voltage (as well as the max voltage of a rechargeable cell) is a product of cell's chemistry. Most common Lithium Ion cells (LiPo, NCA, NMC) have the nominal voltage of 3.7v, with maximum voltage being 4.2v. The bicycle cells you're referring to are LFP cells with 3.2v nominal and 3.65V max.

Then, Lead-Acid batteries behave completely differently than rechargeable Lithium batteries, so comparing to them is pointless.

Finally, the cells you've got are PRIMARY cells, for which max voltage is typically not specified since they're not rechargeable, but pushing them like 25% over their OCV seems like a strange move.

well, 3.2 is to 3.6 as 48 is to 54. So there is that... As I wrote.

Lead acid technologies were NOT compared, only used in example of charge voltage HIGHER than battery nominal.
'taint rocket science!

Pushing them, That remains.

The batteries were monitored by feel. They remained "felt" just above ambient in a cool room. I doubt the internal tamp exceeded 80 degrees F. 150mv for an hour is not much heat.

Pushed or not, How to tell? I'm going to run then each down to about 2.8V and go after them again and see how they do.

Of course, this little exercise will not help me maintain or optimize any of the other battery packs.

Do you know the pack for the bike costs $500. and I could spend more!

Planed obsolescence has never been an alluring feature for me.

 

[crickets]

well, 3.2 is to 3.6 as 48 is to 54. So there is that... As I wrote.

Lead acid technologies were NOT compared, only used in example of charge voltage HIGHER than battery nominal.
'taint rocket science!

Well, I get no cookie even if I educate you. Just remember that nominal means "at 50% on the discharge curve (even if it's a flat line)" and that Lead-Acid is purposefully charged above its max voltage, while Lithium is never charged above the max voltage.

 

[rons]

Discharge your battery fully before a recharge operation.

 

[CalG]

Discharge your battery fully before a recharge operation.

I believe that is not applicable to today's Li Ion cells.

 

[greif1]

Recharging primary cells will cause some gas and venting, causing some drying. Add that to the age which also causes drying and you have a cell of diminished capacity. Many batteries use part of the outer case as part of the circuit, so as time goes by, the walls get thinner and leakage likely. All in all- recharged would not be anything close to reliable.

 

[Tony Quiring]

Lithium batteries come in both types...

Had some smaller cells from a flashlight that went weak.

Also had one of those popular high power lights with the charger, voltage looked same so tossed it in charger and left it.

This was on the steel bench, all good.

Came back a couple days later, charger and battery GONE!

The cord still plugged in so found it hanging off bench, no battery.

About 15 feet away in front of another bench we see a black spot on the floor...

It seems the battery became a rocket. Pushed the charger then flew across and landed on the wood floor and torched a hole.

Lucky there was notenough fuel to light the wood floor. 1 1/8 plytainium, has good hole now.

Look close at voltage, rechargeable ones have higher voltage rating than not chargeable.

Coin batteries are not expensive, Amazon has one packs not cheap but bulk packs good price.

Not worth the risk of damage, toss them.

Sent from my SM-G781V using Tapatalk

 

[CalG]

Tony

Your tale and images depict what I would call "An Idiots way of working with batteries".

A charger suited to one task was applied to another, and the blame for the fiasco falls on the attempt to try something.

It's no wonder most of us are scared to go out doors.

By the way.

Battery Number one 3.398 Volts and holding
Battery Number two 3.785 Volts and holding.

I'm measuring them daily over the next few days, then perhaps in a month.

If the take out can supply memory holding current for umpteen years, these "cast offs" just might for years beyond my lifetime ;-)

Heck, I could pair them up and really put a spin on Volts/ amps and hours! ;-) (no, I'm not doing that 'cause one cell would always be fighting the other, and both would suffer for the conflict.)