One thing that I have noticed is when a set of batteries (alkaline) are close to fully discharged, they also tend to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working. This suggests to me that the batteries are changing size, resulting in a poor fit within the battery compartment despite a prior good fit when the batteries had a good charge. The change in size, if any, is very small because the batteries don’t look any different, and don’t have any surface distortions that would indicate an internal change in volume. But it should be noted that it would be quite unlikely that the battery components of a discharged battery would have exactly the same volume as the battery components of the corresponding fully charged battery.

Could be. Or maybe spending that long in a tight-fitting compartment compresses them slightly.

No.

If it does change it may be the mass, but I suspect even if it did it would be so small a change as to be basically immeasurable

KJW said:

… they also tend to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working.

I do not experience this.

sibeen said:

No.

If it does change it may be the mass, but I suspect even if it did it would be so small a change as to be basically immeasurable

so the small change is too big to be measured?

what is the device?

I suppose the anode could shrink during charging? It might oxidize during discharge and expand.

transition said:

what is the device?

Remote controls (typically using AAA batteries).

Bubblecar said:

Or maybe spending that long in a tight-fitting compartment compresses them slightly.

I guess that’s a possibility. However, one could distinguish this possibility by checking rarely used devices (long time in battery compartment but still charged).

sibeen said:

If it does change it may be the mass

I assume that such batteries are sealed, so no change in mass (apart from that associated with relativistic mass-energy equivalence).

KJW said:

sibeen said:

If it does change it may be the mass

I assume that such batteries are sealed, so no change in mass (apart from that associated with relativistic mass-energy equivalence).

There’s a gas vent in alkaline batteries, so there may be a little mass change (in addition to the 4 ng/g relativistic mass change). There may be a little length change in cheap batteries if the compression due to the springs is enough to deform the end caps. More likely is that the spring pressing the end of the battery has a reduction of tension by being compressed for so long.

party_pants said:

KJW said:

… they also tend to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working.

I do not experience this.

I’ve experienced it with a few different remote controls. However, it was only recently that I associated it with nearly discharged batteries.

btm said:

KJW said:

I assume that such batteries are sealed, so no change in mass (apart from that associated with relativistic mass-energy equivalence).

There’s a gas vent in alkaline batteries

Ok, I didn’t know that.

btm said:

More likely is that the spring pressing the end of the battery has a reduction of tension by being compressed for so long.

I don’t think so, because the problem seems to be fixed by replacing the batteries. That is, the problem seems to be with the batteries rather than the battery compartment.

KJW said:

One thing that I have noticed is when a set of batteries (alkaline) are close to fully discharged, they also tend to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working. This suggests to me that the batteries are changing size, resulting in a poor fit within the battery compartment despite a prior good fit when the batteries had a good charge. The change in size, if any, is very small because the batteries don’t look any different, and don’t have any surface distortions that would indicate an internal change in volume. But it should be noted that it would be quite unlikely that the battery components of a discharged battery would have exactly the same volume as the battery components of the corresponding fully charged battery.

I change a lot of batteries and swelling does occur but none ever shrink. The contacts weaken but this is not due to change in battery size.

KJW said:

transition said:

what is the device?

Remote controls (typically using AAA batteries).

The dislodging may be due to frequent dropping or moving the remote control.

Divine Angel said:

KJW said:

transition said:

what is the device?

Remote controls (typically using AAA batteries).

The dislodging may be due to frequent dropping or moving the remote control.

Indeed. The connectors are easily deformed.

>Remote controls (typically using AAA batteries).

couple things

any tarnishing/oxidation of terminals (spring or whatever) causes voltage drop, which is worse in the situation of battery types that start off with a lower terminal voltage (comes closer to minimum V operating threshold easier). Different battery types have different terminal voltage (and discharge slopes). Also, in very light duty devices self-discharge is an important factor, even with batteries that have low self-discharge rates). Further, related, a knackered battery can appear charged based on the terminal voltage, but have little or no Ah capacity.

the diameter of battery types can vary a bit, manufacturers sometimes go to a slightly larger size to get more Ah, to the extent they can be a very tight fit*

*related – the plus terminal that sticks out (on the battery) are sometimes larger and won’t fit into the plastic indent that holds the metal terminal contact properly (in the device).

party_pants said:

KJW said:

… they also tend to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working.

I do not experience this.

From ancient memory, I have experienced this. Or to put it more precisely, I’ve noticed that batteries sometimes become dislodged from battery compartments after time. It hadn’t occurred to me that discharging had anything to do with the volume change.

My father in law has noticed that supposedly similar batteries (AA or AAA) have slightly different dimensions, newer batteries have a noticeably (eg. 0.5 mm) shorter height on the positive terminal. This difference in height was making it impossible to replace the batteries in a TV remote control, until I bent the terminals within the remote a bit.

I would have thought no too, searched for “battery changing size discharged”

http://physics.stackexchange.com/questions/34421/does-the-mass-of-a-battery-change-when-charged-discharged

Does the mass of a battery change when charged/discharged?

Yes, the total mass of a battery increases when the battery is charged and decreases when it is discharged.

The difference boils to Einstein’s E=mc2 that follows from his special theory of relativity. Energy is equivalent to mass and c2, the squared speed of light, is the conversion factor.

Tau.Neutrino said:

I would have thought no too, searched for “battery changing size discharged”

http://physics.stackexchange.com/questions/34421/does-the-mass-of-a-battery-change-when-charged-discharged

Does the mass of a battery change when charged/discharged?

Yes, the total mass of a battery increases when the battery is charged and decreases when it is discharged.

The difference boils to Einstein’s E=mc2 that follows from his special theory of relativity. Energy is equivalent to mass and c2, the squared speed of light, is the conversion factor.

Yeah, that has already been mentioned.

An example: You can pull approximately 5 million Joules out of a 12 volt 100 amp/hour battery. The weight of the battery is about 33 kg. The change in weight is about 55 pico kg (55 × 10^-12 kg). That would be fairly hard to measure.

Far be it from me to challenge someone who knows about electickery, but I’m not convinced by the confident “no”.

There is a chemical reaction going on. Electrons are changing orbit. Why shouldn’t there be a change in volume (may orders of magnitude greater than the change in mass)?

Batteries can change physical size with corrosion

Tau.Neutrino said:

I would have thought no too, searched for “battery changing size discharged”

http://physics.stackexchange.com/questions/34421/does-the-mass-of-a-battery-change-when-charged-discharged

Does the mass of a battery change when charged/discharged?

Yes, the total mass of a battery increases when the battery is charged and decreases when it is discharged.

The difference boils to Einstein’s E=mc2 that follows from his special theory of relativity. Energy is equivalent to mass and c2, the squared speed of light, is the conversion factor.

Battery mass changes much more than that, because of chemical reactions with oxygen and water in the air, and reactions with chemicals in the materials of the battery holder. More to the point, there’s also evaporation. Water in the electrolyte will be lost through evaporation.

There’s a difference between size and mass. In batteries we have phase changes as solids dissolve and come out of solution. Add to that the absorption of liquids by solids and the production of gas (rare but happens), and changes in density due to pressure. As a result even at constant mass the volume will change a bit.

PS. Who’s Tau.Neutrino?

mollwollfumble said:

Tau.Neutrino said:

I would have thought no too, searched for “battery changing size discharged”

http://physics.stackexchange.com/questions/34421/does-the-mass-of-a-battery-change-when-charged-discharged

Does the mass of a battery change when charged/discharged?

Yes, the total mass of a battery increases when the battery is charged and decreases when it is discharged.

The difference boils to Einstein’s E=mc2 that follows from his special theory of relativity. Energy is equivalent to mass and c2, the squared speed of light, is the conversion factor.

Battery mass changes much more than that, because of chemical reactions with oxygen and water in the air, and reactions with chemicals in the materials of the battery holder. More to the point, there’s also evaporation. Water in the electrolyte will be lost through evaporation.

There’s a difference between size and mass. In batteries we have phase changes as solids dissolve and come out of solution. Add to that the absorption of liquids by solids and the production of gas (rare but happens), and changes in density due to pressure. As a result even at constant mass the volume will change a bit.

PS. Who’s Tau.Neutrino?

me, CrazyNeutrino

Tau.Neutrino said:

me, CrazyNeutrino

Thank’s for dropping the “crazy”. I’ve often wanted to share your posts with my daughter but haven’t dared, because her middle name is Neutrino and I don’t want to suggest to her that she might be crazy.

mollwollfumble said:

I’ve often wanted to share your posts with my daughter but haven’t dared, because her middle name is Neutrino and I don’t want to suggest to her that she might be crazy.

That’s crazy :)

The Rev Dodgson said:

mollwollfumble said:

I’ve often wanted to share your posts with my daughter but haven’t dared, because her middle name is Neutrino and I don’t want to suggest to her that she might be crazy.

That’s crazy :)

I’m feeling less promiscuous without crazy, like its having a placebo effect.

Tau.Neutrino said:

The Rev Dodgson said:

mollwollfumble said:

I’ve often wanted to share your posts with my daughter but haven’t dared, because her middle name is Neutrino and I don’t want to suggest to her that she might be crazy.

That’s crazy :)

I’m feeling less promiscuous without crazy, like its having a placebo effect.

That is the way of the Tau

mollwollfumble said:

party_pants said:

KJW said:

… they also tenhttps://tokyo3.org/forums/holiday/posts/1002450/d to become dislodged within the battery compartment of the device, requiring frequent readjustment for the device to continue working.

I do not experience this.

From ancient memory, I have experienced this. Or to put it more precisely, I’ve noticed that batteries sometimes become dislodged from battery compartments after time. It hadn’t occurred to me that discharging had anything to do with the volume change.

It doesn’t.

The Rev Dodgson said:

Far be it from me to challenge someone who knows about electickery, but I’m not convinced by the confident “no”.

There is a chemical reaction going on. Electrons are changing orbit. Why shouldn’t there be a change in volume (may orders of magnitude greater than the change in mass)?

Yes but the spring in the contact is well able to cope with it unless they have been compromised.

roughbarked said:

mollwollfumble said:

party_pants said:

I do not experience this.

From ancient memory, I have experienced this. Or to put it more precisely, I’ve noticed that batteries sometimes become dislodged from battery compartments after time. It hadn’t occurred to me that discharging had anything to do with the volume change.

It doesn’t.

It’s possible if the electrolyte evaporates due to a faulty container, or if hydrogen escapes through the container. But you’re right in that it’s more likely to be dimension change of the compartment in which the battery sits.

mollwollfumble said:

roughbarked said:

mollwollfumble said:

From ancient memory, I have experienced this. Or to put it more precisely, I’ve noticed that batteries sometimes become dislodged from battery compartments after time. It hadn’t occurred to me that discharging had anything to do with the volume change.

It doesn’t.

It’s possible if the electrolyte evaporates due to a faulty container, or if hydrogen escapes through the container. But you’re right in that it’s more likely to be dimension change of the compartment in which the battery sits.

It is all about cheap shit fittings.

I think I need to stress that the problem was fixed by replacing the batteries. Thus, the cause of the problem was the batteries, not the battery compartment. Nor was the problem caused by general use such as moving or dropping the remote control.

I should remark that the problem developed rather quickly from a long period of no problem to requiring very frequent readjustment of the batteries in the battery compartment, and immediately returning back to no problem when the batteries were replaced. That is, the changes were rather drastic and not in any way subtle.

KJW said:

I think I need to stress that the problem was fixed by replacing the batteries. Thus, the cause of the problem was the batteries, not the battery compartment. Nor was the problem caused by general use such as moving or dropping the remote control.

I should remark that the problem developed rather quickly from a long period of no problem to requiring very frequent readjustment of the batteries in the battery compartment, and immediately returning back to no problem when the batteries were replaced. That is, the changes were rather drastic and not in any way subtle.

I still believe that you are using too small a sample. The power of one isn’t good enough. How many remotes have you looked at to come to this conclusion? How many brands of batteries have been involved in coming to this conclusion?

The problem is always fixed by changing the batteries. The old ones are flat or in other terms can no longer supply the power required.

If anything at all, moving the batteries gives the contacts slightly different purchase by relieving the spring contacts enough and by breaking the film that develops between battery and contact. The lower the power supply gets, the more the contact importance becomes. By moving the batteries you will get a few more minutes or hours, perhaps even days out of a battery which if removed and put on a battery tester will actually show you how they are perfotming under load.

On my Citizen multi tester, I added a switch and a light bulb from a digital watch. I put any suspect battery on it and apply the load of the light bulb. Any good battery will not show much drain but the ones that still show full voltage quickly drop away to way below the voltage required.

roughbarked said:

The problem is always fixed by changing the batteries. The old ones are flat or in other terms can no longer supply the power required.

If anything at all, moving the batteries gives the contacts slightly different purchase by relieving the spring contacts enough and by breaking the film that develops between battery and contact. The lower the power supply gets, the more the contact importance becomes. By moving the batteries you will get a few more minutes or hours, perhaps even days out of a battery which if removed and put on a battery tester will actually show you how they are perfotming under load.

So we are in agreement that it was the batteries that were the cause and not the battery compartment. And we are in further agreement that it was the nearly discharged batteries that were the cause. However, it needs to be stressed that there was enough charge for the remote control to work after readjustment of the batteries within the compartment, that the batteries were not completely discharged, although it was not known how much charge remained.

I initially thought that perhaps there was a thin oxide film impeding the current flow, which was broken when the batteries were readjusted, enabling metal-to-metal contact. But the key thing that led me to reconsider is that the batteries became dislodged within the compartment. It wasn’t just that the nearly discharged batteries couldn’t deliver enough power, but that they no longer fit properly in the battery compartment.

roughbarked said:

I still believe that you are using too small a sample. The power of one isn’t good enough. How many remotes have you looked at to come to this conclusion? How many brands of batteries have been involved in coming to this conclusion?

We are not dealing with statistical events. Think of it like a car crash where each crash has its own cause to be determined, and that it doesn’t need a lot of crashes to form a statistically significant sample size.

Note that my question was specifically about whether or not batteries change size during discharge. It wasn’t really asking about possible causes for the frequent failure of the remote control.

KJW said:

roughbarked said:

The problem is always fixed by changing the batteries. The old ones are flat or in other terms can no longer supply the power required.

If anything at all, moving the batteries gives the contacts slightly different purchase by relieving the spring contacts enough and by breaking the film that develops between battery and contact. The lower the power supply gets, the more the contact importance becomes. By moving the batteries you will get a few more minutes or hours, perhaps even days out of a battery which if removed and put on a battery tester will actually show you how they are perfotming under load.

So we are in agreement that it was the batteries that were the cause and not the battery compartment. And we are in further agreement that it was the nearly discharged batteries that were the cause. However, it needs to be stressed that there was enough charge for the remote control to work after readjustment of the batteries within the compartment, that the batteries were not completely discharged, although it was not known how much charge remained.

I initially thought that perhaps there was a thin oxide film impeding the current flow, which was broken when the batteries were readjusted, enabling metal-to-metal contact. But the key thing that led me to reconsider is that the batteries became dislodged within the compartment. It wasn’t just that the nearly discharged batteries couldn’t deliver enough power, but that they no longer fit properly in the battery compartment.

roughbarked said:

I still believe that you are using too small a sample. The power of one isn’t good enough. How many remotes have you looked at to come to this conclusion? How many brands of batteries have been involved in coming to this conclusion?

We are not dealing with statistical events. Think of it like a car crash where each crash has its own cause to be determined, and that it doesn’t need a lot of crashes to form a statistically significant sample size.

Note that my question was specifically about whether or not batteries change size during discharge. It wasn’t really asking about possible causes for the frequent failure of the remote control.

I know what your question is about. I also want to point out that no, we are not in agreement that batteries are the cause and that battery compartments are not nor did I suggest anywhere that nearly discharged batteries were any different from fully charged ones in fitting existing battery compartments. Others have pointed out that different batteries may appear to be different sizes. I’ve asked you how many brands of batteries you have tested the theory on.

I’ll also remind that all batteries though maybe looking different, carry an identity, which actually happens to be the size. A lot of batteries look different but they all actually fit the same vernier caliper. Some people have tried changing their watch batteries and a few succeeded, I’ll point out that a 626,621 or 616 battery all have one common featurem the initial 6 = diameter. the following numbers = height.
The one thing that may be different, is the battery compartment. These differ with the design of every device. Designers may know stuff but it doesn’t make them the sharpest knives in the drawer.

Others have mentioned batteries banging about inside battery compartments which you have tried to deny but other designers screw clamps down tight in an attempt to avoid this problem.

Solid state electronic circuits work better why? Because nothing can move and if it for some reason does, the thing is dead.

We have covered the fact that batteries may swell and even explode. A railway line originally had gaps to allow for expansion but where did they contract back to?

Spring contacts in battery compartments allow for expansion but have a poor track record of coping with contraction. A rate of battery contraction may exist but it will be infinitesimal.
It will also first require expansion and will be constrained as to how far it can contract.
However, most battery spring contacts will survive numerous battery changes without problems. Which leads me to point at the bleeding obvious that they are quite capable of surviving the tiniest of battery contractions.

Now, to do an experiment. Why don’t you try? : putting batteries of known charge from full to almost flat in the freezer for 24 hours and then record the results of installing them in your unadjusted battery comparrtment.

roughbarked said:

I also want to point out that no, we are not in agreement that batteries are the cause and that battery compartments are not

Then why did you say: “The problem is always fixed by changing the batteries.”? If the problem was the battery compartment, it would not be fixed by changing the batteries.

roughbarked said:

nor did I suggest anywhere that nearly discharged batteries were any different from fully charged ones in fitting existing battery compartments

That’s actually my claim.

roughbarked said:

I’ve asked you how many brands of batteries you have tested the theory on.

I haven’t “tested” the theory at all. I’m simply recalling what I have noticed and asked whether a particular explanation has any likelihood of being true.

roughbarked said:

Others have mentioned batteries banging about inside battery compartments which you have tried to deny but other designers screw clamps down tight in an attempt to avoid this problem.

I’m not sure what point you are making here. In those particular battery compartments that I have observed, the batteries happily fit for a long period of time until suddenly they stop fitting properly. Then when the batteries are replaced, those new batteries happily fit. Whether new batteries rattle around inside other battery compartments is beside the point. On further consideration, I recall that the problem has also occurred with battery operated wall clocks, for which the only movement is the gentle ticking of the clock.

roughbarked said:

We have covered the fact that batteries may swell

Is this during normal discharging? If so, why are we continuing to debate this? If it occurs abnormally, it is irrelevant to the discussion since I’m only interested in normal use.

roughbarked said:

Now, to do an experiment. Why don’t you try? : putting batteries of known charge from full to almost flat in the freezer for 24 hours and then record the results of installing them in your unadjusted battery comparrtment.

It would be easier to simply change the batteries and be done with it. But if I were to do an experiment (unlikely), it would be to measure the change in size of a battery during discharge. In the opening post, I provided indirect evidence that the battery changes size. But a direct measurement would settle the issue once and for all.

roughbarked said:

Spring contacts in battery compartments allow for expansion but have a poor track record of coping with contraction. A rate of battery contraction may exist but it will be infinitesimal.
It will also first require expansion and will be constrained as to how far it can contract.
However, most battery spring contacts will survive numerous battery changes without problems. Which leads me to point at the bleeding obvious that they are quite capable of surviving the tiniest of battery contractions.

I didn’t indicate it in the opening post, but I think it’s the cross-section of the battery that changes size rather than the length.

KJW said:

I didn’t indicate it in the opening post, but I think it’s the cross-section of the battery that changes size rather than the length.

In which case it wouldn’t be loose. Batteries are designed to touch the contacts, not the sides.

KJW said:

roughbarked said:

I also want to point out that no, we are not in agreement that batteries are the cause and that battery compartments are not

Then why did you say: “The problem is always fixed by changing the batteries.”? If the problem was the battery compartment, it would not be fixed by changing the batteries.

Because the batteries are flat and they won’t power the unit. That’s why you open it to take them out.

You believe that they are more loose than you thought they were.

leave ‘em in there all snuggled up, you know, i’ve done it myself, not in a battery compartment though

roughbarked said:

KJW said:

I didn’t indicate it in the opening post, but I think it’s the cross-section of the battery that changes size rather than the length.

In which case it wouldn’t be loose. Batteries are designed to touch the contacts, not the sides.

On the contrary, when a battery is inserted into the battery compartment of a typical remote control, the battery is in contact with the back surface of the compartment. If the battery swells, then this will tend to push the battery out of the compartment. On the other hand, if the battery shrinks, then the battery will lose contact with the back surface of the compartment, more-or-less becoming suspended within the compartment by the terminal contacts. But the terminal contacts are exerting a compression force on the battery, which leads to mechanical instability and the likelihood of the battery becoming dislodged.

KJW said:

roughbarked said:

KJW said:

I didn’t indicate it in the opening post, but I think it’s the cross-section of the battery that changes size rather than the length.

In which case it wouldn’t be loose. Batteries are designed to touch the contacts, not the sides.

On the contrary, when a battery is inserted into the battery compartment of a typical remote control, the battery is in contact with the back surface of the compartment. If the battery swells, then this will tend to push the battery out of the compartment. On the other hand, if the battery shrinks, then the battery will lose contact with the back surface of the compartment, more-or-less becoming suspended within the compartment by the terminal contacts. But the terminal contacts are exerting a compression force on the battery, which leads to mechanical instability and the likelihood of the battery becoming dislodged.

I’ve been paying particular attention to devices containing AAA batteries, including remote controls. I know you are trying to blame a tiny amount of expansion contraction but I’m still concerned that in the case of an LED torch or an optical sender, that the required amount of power supply isn’t there until the device is given a tap or the battery rotated in the case. This means that it is the mechanical instability that is causing the problem. If these contacts are changed for the type that screw down tight, will the battery become loose?

If it doesn’t change size, then why does it go flat? eh! answer that!

I read something recently about batteries in mobile phones and how they (apparently) expand after a few thousand charging cycles. Damned if I can remember where I read that, though.

Divine Angel said:

I read something recently about batteries in mobile phones and how they (apparently) expand after a few thousand charging cycles. Damned if I can remember where I read that, though.

They need to be changed as soon as this is noticed. If any battery has visibly swollen, it is a sick battery and should be disposed of appropriately.

Divine Angel said:

I read something recently about batteries in mobile phones and how they (apparently) expand after a few thousand charging cycles. Damned if I can remember where I read that, though.

Perhaps they get pregnant cos they are fucked?

bob(from black rock) said:

Divine Angel said:

I read something recently about batteries in mobile phones and how they (apparently) expand after a few thousand charging cycles. Damned if I can remember where I read that, though.

Perhaps they get pregnant cos they are fucked?

yep. :)

probably’s often B+ receiver contact, it’s positive (tending oxidation), it doesn’t get changes like the battery, the contact area maybe small, and the battery may gas at that end.

transition said:

probably’s often B+ receiver contact, it’s positive (tending oxidation), it doesn’t get changes like the battery, the contact area maybe small, and the battery may gas at that end.

yes. I’m thinking it is more about all of that.

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

I have suggested this. For those who think a significant change is measurable.
I’ve suggested freezing some first too.

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

Tamb said:

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

duct tape but you’d need to recalibrate.

transition said:

probably’s often B+ receiver contact, it’s positive (tending oxidation), it doesn’t get changes like the battery, the contact area maybe small, and the battery may gas at that end.

couple other things

on the negative spring end the contacts have some sideways movement ability without much change to the contact surfaces(too it’s a sorta wide circle that’ll somewhat sit flat, and make contact somewhere , further, in contrast, at the other end the B+ has the drag etc of the battery holder.

thing is on the positive end you have the problems of contact area/force and state of contact surfaces. Large contact surfaces are fine if they butt neat flush and are clean and have suitable pressure(for the working life without maintenance)no grime/dirt/oxidation – good electrical contact

otherwise you use a smaller contact surface, which is fine but if that small contact cross section has any high R about it then there’s no other contact point to do the job.

Tamb said:

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

can if you want to. depends on how proficient at using verniers you are, how quick you do it.

roughbarked said:

Tamb said:

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

duct tape but you’d need to recalibrate.

Yes or glad wrap & subtract its thickness

ChrispenEvan said:

Tamb said:

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

can if you want to. depends on how proficient at using verniers you are, how quick you do it.

Also depends on the type of battery. A watch battery would be flat by the time you did it if the vernier handles didn’t insulate your hand from contact.

ChrispenEvan said:

Tamb said:

ChrispenEvan said:

why doesn’t someone, someone who cares, get a vernier and measure the batteries before and after?

Insulate the metal vernier from the battery.

can if you want to. depends on how proficient at using verniers you are, how quick you do it.

It is a dead short so would begin to discharge the battery.

Tamb said:

ChrispenEvan said:

Tamb said:

Insulate the metal vernier from the battery.

can if you want to. depends on how proficient at using verniers you are, how quick you do it.

It is a dead short so would begin to discharge the battery.

immediately.

a couple of seconds. ain’t going to make much difference. and we are talking about aa or aaa batteries in this thread.

ChrispenEvan said:

a couple of seconds. ain’t going to make much difference. and we are talking about aa or aaa batteries in this thread.

I just don’t like dead shorting anything electrical.

Tamb said:

ChrispenEvan said:

a couple of seconds. ain’t going to make much difference. and we are talking about aa or aaa batteries in this thread.

I just don’t like dead shorting anything electrical.

He’s right though about not making a lot of difference to the batteries in question. Their life isn’t expected to be long anyway.

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

So the OP is wrong.

Peak Warming Man said:

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

So the OP is wrong.

strokes chin

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

was it the same battery?

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

For transparency, I should have added:
Vernier: Mitutoyo dial vernier p/n 505-634, device stated precision ±0.005mm
Batteries: Eveready Gold Alkaline AAA, p/n A92 LR03, “Use by” date stated on batteries: 12-2025. Batteries were used in a Bose Quiet Comfort 15 noise cancelling headphone.

ChrispenEvan said:

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

was it the same battery?

Yes.

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

to what level of accuracy is your measuring equipment.

My guess would be thermal expansion due to discharge?

btm said:

ChrispenEvan said:

btm said:

Eveready Gold AAA batteries:
Charged: 44.280mm
Discharged: 44.490mm

Measurements repeated several times (before and after) for confirmation.

was it the same battery?

Yes.

I knew they weren’t getting looser as they discharged all along.

Dropbear said:

My guess would be thermal expansion due to discharge?

chemical reaction.

roughbarked said:

btm said:

ChrispenEvan said:

was it the same battery?

Yes.

I knew they weren’t getting looser as they discharged all along.

sure you did

Dropbear said:

My guess would be thermal expansion due to discharge?

That’s possible, but it might also be that the expansion was due to ambient temperature, since that was higher after discharge. I’d need to control that for meaningful measurements.

btm said:

Dropbear said:

My guess would be thermal expansion due to discharge?

That’s possible, but it might also be that the expansion was due to ambient temperature, since that was higher after discharge. I’d need to control that for meaningful measurements.

I assume the batteries were measured at the same temperature before and after?

dv said:

btm said:

Dropbear said:

My guess would be thermal expansion due to discharge?

That’s possible, but it might also be that the expansion was due to ambient temperature, since that was higher after discharge. I’d need to control that for meaningful measurements.

I assume the batteries were measured at the same temperature before and after?

I didn’t measure or control that.

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

Even when not charging…just ask Samsung and Boeing.

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

steady lad…

poikilotherm said:

roughbarked said:

btm said:

Yes.

I knew they weren’t getting looser as they discharged all along.

sure you did

said it in almost every post.

poikilotherm said:

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

Even when not charging…just ask Samsung and Boeing.

the bulging is what is suspected to have caused the shorts, leading to the fires.. expansion caused a crack in the battery case which lead to electrical shorts

poikilotherm said:

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

Even when not charging…just ask Samsung and Boeing.

Indeed so and it isn’t new only to LION batteries.

Dropbear said:

poikilotherm said:

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

Even when not charging…just ask Samsung and Boeing.

the bulging is what is suspected to have caused the shorts, leading to the fires.. expansion caused a crack in the battery case which lead to electrical shorts

I’ve araldited the battery casing on this laptop.

stumpy_seahorse said:

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

steady lad…

he aint lion

dv said:

stumpy_seahorse said:

Dropbear said:

bulging during charge is a real phenomenon with LION batteries and the results can be disastrous

steady lad…

by the look on her face, she wasn’t happy with the amount of bulging… nor the speed of discharge…

i doubt .2mm is going to make a difference either way. there is that darned spring to give or take up and change.

ChrispenEvan said:

i doubt .2mm is going to make a difference either way. there is that darned spring to give or take up and change.

I’m with you. 200μm is well within thermal expansion tolerance. According to TATE new AAA batteries are 44.5mm long.

there’s various thresholds with IR remote.

there’s minimum operating V of the eletronics(which it may dip under when loaded), and down the lower voltages it may still work but the range of the unit is reduced. Quite often with a flat battery the units will work still if the distance between sender and receiver is reduced, like right up close. So really a flat battery, in context, might be that it doesn’t work to the distances you’d usually use it.

IR LEDS get dirty, as do receiver unit. Light on the receiver also can desensitize the receiver.

thing is the remote signal could be dropping into the receiver noise, unable to be decoded, which appears the same as the remote has stopped working.

a small voltage drop on the terminals may take a fringe reception down into or near the receiver noise (including ambient light) at typical distances.

Anyway, I haven’t yet found a loose AAA battery. They constantly stop sending power of the correct amount required yes but the battery isn’t loose. Though rotating the batter or giving the unit a jolt will right the problem.

My headlamp often has loose batteries but that is due to spring contacts that weaken from movement.

roughbarked said:

… They constantly stop sending power of the correct amount required yes …

need The Joule Thief.

ChrispenEvan said:

roughbarked said:

… They constantly stop sending power of the correct amount required yes …

need The Joule Thief.

;)

ChrispenEvan said:

roughbarked said:

… They constantly stop sending power of the correct amount required yes …

need The Joule Thief.

6.2 B