Small Battery Questions

No, my fancy shmancy press is AC.

So basically what you're saying is that my idea is impractical? This may be why there are no cordless warmers of this type... because they drain battery life too quickly.

And that's a good to know fact about 9v. I had no idea. Thank you.

Some electronics require more than a few volts to function.

9V are used in the case of portable radios to power the speaker and my IR thermometer is 9 V. Maybe that's because of the built-in laser pointer, don't know.

Insulated cup sounds good to me.

Eh, I use enough insulated cups on the road. Not going to use them at home as well. Plastic lids aren't the same for appreciating good coffee on a weekend.

I'll probably try to cut away a slot in between the double steel bottom of my stainless steel press and slide the plug-in warmer in there. That will at least work better than the crappy insulating properties of the press itself.

Thanx. That's a good site for the basics.

I took apart a 9 volt battery once. As I remember, it had horizontal layers, covered with some kind of wax.

Did I miss something?

Interesting. Maybe they make them differently nowadays. I have some dead ones in the basket of dead batteries to go to hazardous waste. I think I will autopsy some.

As a kid 50 years ago I opened one PP9 and it had 6 rectangular carbon paste cells stacked on top of each other with wax coating same as even modern PM9 9v battery. Today they are assembled using 6 AAA batteries as in Lin's picture.

Thanks, I stand corrected. I was a long time ago I ripped one apart. I suspect it was an el cheapo knock off battery.

Thanks! I thought I was just hallucinating.

That is only one type of 9V battery. Another type uses a stack of little rectangular cells, vaguely similar to "button"cells.

I just recently took my box of dead batteries in for recycling, so I don't have any to dissect and/or photograph...

EDIT: I hadn't read the rest of the thread to see that Bigg beat me to it...

http://goughlui.com/2015/05/05/mega-teardown-an-assortment-of-alkaline-9v-batteries/

Take a look at the Eveready Energizer teardown. I've seen these stacked 1.5V cells = 1 9V battery.

So it appears the series can cells is a more successful battery than the "stacked" cell battery? Or is it just that the mfr. can sell far more of the stack cell batteries to the general public so they need more volume production technique for that class?

Good question. I wonder why a manufacturer chooses to produce a stacked cell battery vs AAAA's in series? I remember taking quite a few 9V batteries apart way back in around 1980. Back then it was the stacked cell type and I don't remember seeing one AAAA series type, so my guess is that it's the older method.

Wow! GA to you!

Probably, it really comes down to speedy reliable automated manufacture of the ones with multiples of AAAA cells, that are made in a really fast line.

I have a feeling it's mostly due to manufacturing efficiencies/costs.

I'm going to create a new post on leaking batteries. I just had some Duracell batteries leak in my cordless mouse.

There is nothing worse than cordless mouse pee all over the desk top.

Or on a mouse pad!

The batteries inside the metal case hoax has been around the web for a while. Snopes debunked it some time ago. The one I saw was a lantern battery shell with maybe 24 batteries in it.

4 A, yes? as in AAAA?

flash edit: I hadn't refreshed in awhile. Now I see several said yes, 4A

I have called foul (OT) on myself for indication that the 6 cells inside a 9V battery were AAA when in reality they are AAAA.

Oh......

So in other words AAA's won't fit.

It's because of people like you that I lobby to ban anonymous posters.

Quad-A, I think.

Thank you. I guess there's a reason I didn't go into electrical engineering.

I find the voltages listed in those bottom tables disturbing! "Avg. voltage During discharge"? It should be quite clear that the voltage during discharge varies considerably depending on the current required by the load.

A Real-Time-Clock in a computer or machine uses almost no current, and can run for years on a single cell/battery, while an incandescent flashlight requires considerable current, and will last only a few minutes or maybe hours, depending on the cell size, number of cells, etc. The voltage of the RTC power cell will remain very near full voltage for most, if not all, of its useful life; the flashlight voltage will drop much more quickly, and by the time the cell voltage reaches that described in the tables, the flashlight will be essentially useless.

A new carbon-zinc cell should have 1.55V, if I recall correctly. If the average voltage is 1.1V, then the final voltage is 0.65V. What common device can operate down to a cell voltage of 0.65V?

I have a number of LED flashlights that run on 3-AAA cells. They stop working entirely when the cell voltage drops to about 1.3V. I have a number of those 1.3V cells, which I haven't discarded, hoping to find a device that can extract more energy before I recycle them.

use them in a clock

I thought about that, but then I'd have to replace the clock batteries more frequently...

GA. To complete the story, one can get AA-sized cells with Li-ion chemistry and an internal regulator to deliver 1.5V for a very long time.

Nice tables!

Actually, I'm better at figuring out alternate ways to get something done, rather than pushing my way through something I know little about. I'll come up with another route to get to what I'm trying to accomplish.

We used to use "thermos" bottles for hot coffee. They had an inner and outer silvered glass bottle with vacuum in between. (It's also called a Dewar flask.) The vacuum prevented heat loss by convection and the silvering heat loss by radiation. I think they'll keep coffee hot for about 24 hours.

https://en.wikipedia.org/wiki/Vacuum_flask

The family joules....

Not ALL cylindrical batteries are 1.5Vdc...ie: the CR123A is 3Vdc and cylindrical and looks like a 2/3's scale version of a 1.5Vdc C-cell.

Thank you, you answered all my questions very clearly.

Back to the drawing board.

I like you response because it instill self education/self help.

Way back when I was in 5th grade, we had to take a science class. We did a lot of things with both sizes of lantern batteries.

Experimenting with batteries was a lot of fun. I often wonder if it's one of the reasons why I became an EE.

I suspect the 12V one will work better, since P = VI, so less current would produce the same quantity of heat in a given time. This might allow the battery "recovery" process to improve the next shot of current considerably, and so on, until it is drained.

A small 12V lead-acid battery properly charged between uses, is not too heavy to take with, unless you are walking, and do not want a battery in your backpack.

Other voltages are available, such as the BLR154, sometimes used in multimeters:

1. yes, the batteries are all approximately 1.5 V, consisting of precisely one cell.

2. 9V batteries are just that - batteries comprised of multiple (in this case 4) cells. Since the 9V batteries are 4 cells in series, the internal resistance gets multiplied by 4 at the output of the battery, hence these are not for high current draw.

You will want to use something other than these batteries to keep your coffee warm, seriously. Get a Thermos. Have you ever tasted 50 hour old coffee, really?

My French press is a vacuum jacketed stainless steel one. It keeps coffee warm until I drink my 2 cups worth.

You may have gotten some bad loco weed, unless those 4 batteries are special 2.25 V each.

Damned Chick-Fil-A salad greens! You are correct, there are six 1.5 V cells required to make 9 V, which multiplies the output impedance of one cell (as in the 9 V battery) by 6. I apologize with all due regret for momentary loss of math functions.

It looks like you need another cup...

That 1.5 V is VERY approximate, with full charge voltages ranging from 1.2-1.65V. From Wiki:

Since, as you say, AAs consist of a single cell, they really should not be called batteries; of course I do know that common usage, and even the packaging (at least on Duracell™ brand) use the term battery.

But your bigger error is getting 9V from 4 cells. It takes at least 6, and I'm virtually certain you knew this...

And I even showed him pictures. Go figger.

Really, I did not see any of the other posts, or I would have easily avoided my mistake. I was also on a sugar high from cookies at break this morning, and a Subway loaded sandwich.

No Lyn has been sniffing around my back shop, and found my supply of locoweed, and accused me of smoking it.

It really wasn't that good.

I've gotten better stuff out of a ditch in Arkansas.

I not have the benefit of seeing other posts when I replied, and I was in a big fat hurry, so much that I left out 2 cells in the "9V" battery, so it was really 6 V. BFS! (Big fat screwup).

None of the phonon cells I have made thus far are good for more than about 20 mA in bright sunlight for a heat source, but the sun does not need focused to the get things up to about 60 C, due to addition of a secret dark ingredient.

I hope to get some with 8" square sheets of magnesium going before too long, hopefully I will be able to get a uniform copper plate on one side, so stack making will be like stacking bricks.

You can get a lot of heat from a Lithium battery this way; https://www.youtube.com/watch?v=AAZ62tUtc0w Jim

I suppose that would re-warm the coffee, but would add to the bitter after-taste, and might actually medicate some psychiatric disorders simultaneously.

Didn't they use to use some form of Lithium to poison coyotes?

GA!

I thought about doing those calculations myself, but haven't had the time.

I'm very used to Imperial measurements (much to my chagrin in US aerospace work), but I'd have done those calculations in metric as you did.

Could you run the numbers for 50 hours?

That's all the OP needed.

My back of the envelop numbers say the insulated flask is still a better choice.

oops - 50 hours - I read it as 90 (it's called engineer-inspired scope creep )

So just 25 or so laptop batteries would do the trick - I suspect even a little more to be honest - but south of 40 I'd guess...

Would the lemons be edible (fit for eating, raw, juiced, marmalade etc) after depleted in battery usage?

Nope! They'd be contaminated with metals.

That's roughly 2,500 lemons.

I would not know how suitable they would be for repurposing, but I doubt they would be unsafe if the areas used as terminals were excised.

You know what the say, "When life gives you lemons, make lemonade"

You could make lemonade for the flies: Fly Killer

Thank you. That's exactly the kind of information I was looking for, just to get a sense of what would be required.

What about the conversion loss from electrical to heat. It's definitely not 100% efficient, so you'll need more than 208W.

That is about the only thing that is 100% efficient! All of the energy fed into a purely resistive device is converted into heat. Now there is also heat created in the battery itself, and in the leads connecting the battery to the resistance. so the battery and leads should be incorporated into the flask, but once again, the powr required makes it impractical.

Yes - agreed... but as you say, you're not likely to get all the heat into your coffee (having the battery immersed in the coffee would give you best bang for buck - but maybe pretty ordinary coffee!)

Whoops, that didn't come out right. Let me try it again.

Electricity will be used to power the heating element. Some of the heat from the heating element will be used to heat the coffee and some will be lost. Therefore, the efficiency of converting electricity to heating the coffee is not 100%.

Yep! You nailed it this time.

Does the part of the energy that heats up the battery count in the efficiency calculation? Really?

As I said,"so the battery and leads should be incorporated into the flask".

Sorry! I missed that sentence, but I was slightly bleary eyed, half-awake this morning.

Good thing I am not a micro-surgeon, or even a height challenged surgeon.

Nothing left to see here. This myth is busted.

Absolutely true.. but I already doubled the result to take into account the higher heat loss - I'm so ballpark already in that calculation I didn't think it warranted an efficiency conversion.

But for a good li-ion laptop battery taken from nominal 100% full to nominal 0% state of charge with a fast discharge rate you might be getting about 75% efficiency (i.e. a very fast discharge rate produces internal heat - running slowly in perfect conditions it might get more like 90% efficiency).

So the nominal 208 W is more like 156 W available.

I did a back-of-envelope for a single good quality deep-discharge lead-acid too. That (a 50 kg (110 lb) battery) might give you about 16 hours of hot coffee. Maybe 24 h if you drain it to empty, which isn't great for it :)

I think that either way, it's not an effective way to heat coffee or ...

I got it! How about using heat from a blow dryer! A suitcase size battery attached to a blow dryer! Absolute genuis! We solved the problem!

A fold up bicycle with its own alternator, small battery, voltage inverter, and cup warmer, $500. Having coffee you might drink 50 hours later (and still enjoy it) - priceless. May I suggest some means of oxygen removal from the head space?

Oxygen removal. Hmmm. I think you're on to something!

By the way, do you remember those old Schwinn bikes with the generator that rubbed on the side of the rear tire? Maybe that could be integrated into the fold up bicycle. Bicycle in a suitcase! Brilliant! http://www.nycewheels.com/brompton-hard-case-travel-box.html?cmp=googleproducts&kw=brompton-hard-case-travel-box&gclid=Cj0KEQjwjem-BRC_isGJlJ-0h-MBEiQAbCimWIBJig3aS-Wgj65GdvQbwGcBiFmHSki2uEErGKvqOGgaAuJG8P8HAQ

Ampacity. The battery voltage follow the rules of the periodic table, and the voltages are governed by that. A brand new alkaline battery is north of 1.6 volts. Lithium, silver, zinc carbon, lead, all different. The little 9 volt batteries have very little current output, and are a stack of cells in a rectangular package. Good for certain electronics. The material in a primary cell battery is consumed, bigger battery more fuel. A alkaline "D" battery can approach 20000 mAh.

This is what I got from a Chinese Supplier in email:

Hello

Amy's greeting here from HPL Battery in China.

Sorry if disturb,we are professional supplier of lithium batteries,following are some of our hot selling models:

12V-----80Ah, 100Ah, 120Ah, 160Ah, 200Ah;

24V-----40Ah, 60Ah, 80Ah, 120Ah, 160Ah, 180Ah, 200Ah, 250Ah;

36V-----40Ah, 60Ah, 80Ah, 120Ah;

48V-----40Ah, 60Ah, 80Ah, 120Ah;

220Wh Portable Power Pack:

Delivery time of samples in 7days after payment and in 15days for bulk order.

Images of the battery packs removed by me.

The voltage potential of any single cell is limited by the difference in oxidation potential between the cathode and anode, minus whatever voltage loss (resistance) from the electrolyte. Dig out your old freshman chemistry book (you did keep that, right?) and find the oxidation potential table and see the differences, You can come up with some exotic combinations that might be much higher than 1.5 volts, but the problems with those cells would limit their use and reliability. Current output, in milliamps per whatever time frame you want is going to be a function of how fast the chemical reaction can occur, driven by the reactivity of the anode and cathode (electrodes), the total surface area and distance between the electrodes and motility of charges within the electrolyte solution. In a sense, electric cell science and corrosion science are the same thing.

An example of available charge/discharge rates can be made using the type of 12 volt batteries used in automotive or marine applications. All the 12 volt (usually these test at 13.8 volts, truth be told) automotive batteries (a battery is technically an assemblage of more than one cell) generally have 9 individual cells. These have traditionally been lead/acid batteries, having lead anodes and lead sulfate cathodes in an acid electrolyte.

A single cell in this type battery may actually consist of multiple folds of lead and lead sulfate plates each connected in parellel, and the cells connected in series. If this type battery needs to deliver a large amp load, for example to turn a large bore, cold internal combustion engine to start it, each cell will be made of many thinner lead/lead acid plates, so there is a large surface to deliver more amps quickly, and to be recharged by the engine's electrical system for the next start.

A battery which must deliver a steady stream of power over a longer time (usually called a deep cycle battery), with a lower peak amp load, for example to run an electric cart or wheelchair, or electric boat motor, will have fewer, but thicker plates so it is more durable for long discharge and recharge cycles.

The same principles will be true for hearing aid batteries or watch batteries (actually, mostly these aren't batteries but cells). Simply looking at voltage of a cell tells us little about the actual delivered power, and the smaller the cell, the less total amperage will be. No magic in any of this.

Where did you see a 12V Lead Acid battery with 9 cells? You set that type character upside-down.

Whoops, should have taken my own advice. 2.1 volts per cell in a lead acid battery, based on oxidation potential. 6 cells.

a 12V car battery has 6 2V lead acid cells. That's why the old batteries had six separate caps. The newer ones have two caps with vents for three cells. Or some are maintenance free sealed batteries where the caps don't come off, unless they're forced off.

Just a slight correction, a Lead Acid car battery deliver Starting amps at 9V that is why in the old days with Coils and ignition points the sparking system used a 9V coil with a load resistor operated by a relay for direct conection of the coil to the battery under starting conditions and then when you let go of the starter position on the key the relay activate and put a in line resistor in series with the coil that will drop 4.8V of the 13.8V charging voltage now used to charge the battery and to run all the electrical devices on the car. A good lead acid wil measure 2.1V per cell and that will give you 12.6V on a good resting battery. When the Alternator run it will provide 13.8V charging voltage and the moment you switch the head lights on, the more current will try to let the voltage drop and that is sensed by the voltage regulator that will increase the voltage and therefore the current through brushes to the stator slip rings to create a bigger rotating magnetic field on the stator and that will induce a bigger AC current into the field coils of the Alternator, this will be rectified by the diode pack and more current result in more voltage and therefore the expected drop does not happen and stay at 13.8V. Starting is the only valid test for a car battery. If the Voltage on a fully charged battery drop lower than 9V it needs replacing. If the resting voltage of a fully charged battery is lower than 12.6V like 10.5V it means 1 cell is Short circiut. A good Alternator will keep the charging voltage 13.8V if you load the system systematic, starting with 13.8V with engine running, ignition and normal radio draw +-6Amp, add Lights, add interior fan, wait for electric radiator fan to kick in, should stay at 13.8V. Good Alternator. 13.8V indicate that the Alternator can supply all the current used by the electrical system and also keep charging the battery to full capacity. Less voltage will calsify the plates and jeopardize Starting current. New Natrium Sulfide System is the same but charging Voltage must be more than 14V, max 14.4V

The cylindrical batteries are 1.5V because they're a single Alkaline cell. They decay from 1.55V when fresh to about 1.1 or 1.0V at end of life. Here's Figure 9.98 from Chapter 9 of our book. BTW, this chapter is available free:

http://artofelectronics.net/wp-content/uploads/2016/02/AoE3_chapter9.pdf

If you take a 9V Alkaline battery apart, you'll see it has six cells packed side-by-side.

http://www.instructables.com/id/Get-Six-15V-Cells-from-One-9V-Battery/

The old penlight batteries in the bigger battery case is really old internet bull at least 6 or 8 years old Check it out on Snopes. I can't believe that people still buy into it.

It's because of people like you that I lobby to ban anonymous posters.

Measure the length of the 6 "cells" and compare it to the length of the 9v case in the picture. Scale shouldn't be an issue as they are next to each other. "They can't fit so this must be bull***t."

Go take one apart.

Then, just go away.

The 9v PP3 battery under discussion here is typically 48.5mm high, 26.5mm wide and 17.5mm deep.

The AAAA (R8D425, LR8D425, 25 etc.) cylindrical cells that are used inside these PP3 batteries are 42.5mm high and 8.3mm in diameter.

Even a dill should be able to figure out that 6 of these will readily fit inside the PP3 case with adequate space for connections.

Check SNOPES for this topic; "mister Ed was a zebra" Jim

You mentioned in a previous post a lantern battery hoax that had 24 cells. If it was truly a standard 6V lantern battery, it would have 4 cells. BUT, there may well be a similarly box-shaped battery that does have 24 cells; it would be a 36 Volt battery. When I was in college, I used batteries that had been the "B" batteries for portable tube radios; they had 200 cylindrical cells held in position by tar, and encased in a cardboard box with the Eveready brand in red ink (I cut several open, to use different numbers of cells for various voltages), and it put out 300 Volts when intact.

Here's a picture I just took of a Duracell Coppertop 9V battery that I just now cut open. Rather than use the normal method of peeling the can off, I used a cutoff wheel in a Dremel tool to remove just enough to see the cells inside, and an Xacto knife to peel away the shrink wrap around the cells, so you can see there is no possibility of faking! You can see the same results of leakage on the top-right cell as you can see on the right terminal.

This is NOT some internet fraud. Go find a couple of old 9V batteries and cut them open yourself!

Good one!

Where do you get hamsters that small? ... And what do they eat? I always wondered what kind of liquid was leaking out of old batteries, now I know!

OK, Let's see what you can do with this view...

Oh no! You idiot!

Don't you know how dangerous it is when you let the horsepower out?