Your typical alkaline battery, whether it's AA or C or D, has a nominal voltage of 1.5V -- that is, it can exert 1.5 "units" of "electrical pressure" on a circuit it's installed into.

That's not a super useful amount of voltage, but 3V is -- and by placing two batteries in series, you end up at 3V because you add the voltages together.

The voltage put out by a battery is determined largely by the materials used. While you can increase the available current by making it bigger (or ganging up a bunch of smaller ones in parallel), the voltage is somewhat fixed.

The standard batteries used for many years had a natural voltage of about 1.5V. But for the transistors of the time, that voltage was not optimal.

There's a hack for that. If you "stack" two batteries in series, then their voltages add up. Two 1.5V batteries will output 3V. If you stack four of them you get 6V. Which was pretty useful when the "standard" for many transistors and integrated circuits was 5V.

A lot of things have changed since those days, of course. Different battery materials are in widespread use, and integrated circuit technology has changed such that 5V is not only undesirable, it's not acceptable.

As transistors were made smaller and smaller ("shrunk"), it became necessary to reduce their supply voltages. This has gone through many phases, from 5V -> 3.6V -> 3V etc. etc. A lot of integrated circuits now are very happy to run on 1V or so. If a gizmo uses only such ICs, it can use a single battery.

But there are at least a couple of reasons to use higher voltages. One is that there are still some old technology devices around that run on a 3V standard, or use signaling busses between them that use a >1V standard. There are also some components, such as certain displays, that work on higher voltages.

It is possible to boost voltages, but a better strategy is often to use a power source that provides the highest voltage needed. For the lower voltage devices, it's relatively easy/cheap to drop the voltage down.

So you use two batteries in series and that provides a nominal voltage of 3V (actually less pretty quickly). For things that don't need that, you reduce the voltage.

Why not just make a battery that spits out 3V?

That would require sticking two batteries together in a permanent sort of way, which would be varying shades of difficult. It would also wreck the current standard paradigm, which is designed around 1.5V battery chemistry. Even a "9V battery" is actually made of six 1.5V cells together, and a 6V lantern battery is made of four.

To get a single-cell battery to spit out 3V, we'd need to find new battery chemistry -- new substances that would spit out 3V.

They do. Lithium (Li-MnO2) batteries output 3V.

Lithium ion batteries output around 3.7 to 4.2V.

Alkaline batteries output around 1.5V.

NiCd batteries output around 1.2V.

Different types of batteries create different amounts of electrical “pressure” as u/ToxiClay put it.

The voltage of a battery cell is determined by its chemical makeup. The common alkaline batteries use Zinc and Manganese which react to produce a certain “concentration of free electrons” (aka voltage). The reaction is at equilibrium when no current is being drawn (moving those electrons out). When the battery is connected to a device, those electrons are drawn out of one end and pushed into the other, which changes the equilibrium of the reaction. The zinc and manganese react to replenish the electrons and reestablish equilibrium until all of the reactants are used up. At that point, the reaction can no longer produce electrons and the battery is dead. Using different reactants will change the equilibrium “concentration” (voltage) of electrons. Since each cell can only produce a certain electron pressure/concentration/voltage according to its chemistry, the way to get higher voltages is to stack them on top of one another.

Or, they would need to affix two 1.5 volt batteries in series in one long battery, except TV remotes have batteries next to each other to save space.

The answer is that 1.5v batteries provide diversitility in how they are used and mounted in devices.

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They "do" but they also don't. The voltage wasn't made specifically for the application but is rather what the chemistry can provide.

Of course they do make 3V batteries, like the “coin type” CR batteries that power watches. And really defeat OP’s “all electronics use 2 batteries” assertion

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The chemistry defines the voltage of the battery. Lithium operates anywhere from 3V to 4.45V or 1.5V.

The biggest challenge between chemistries is going to be energy density compared to other types, cost and sometimes weight and size.

Lithium is becoming battery leader in terms of chemistry, because it has a higher energy density, lower weight and can come in many form factors. The biggest downside is cost.

Alkaline has the benefit that it's low cost, decent for most cases in terms of size & weight ratios. NiCDs are heavier.

Energizer makes lithium AA/AAA that are 1.5V. The biggest benefit over alkaline is that those lithium batteries have longer runtime (also work better in cold). However, the lithium batteries are more expensive and you could probably buy more alkalines for the same cost.

It's worth mentioning that non-rechargables typically hold charge longer than their rechargable counterparts, the benefit of rechargable is that you shouldn't have to recycle rechargables away after it discharges. This means on one charge cycle, you'll have to charge the rechargable before the non-rechargable. Non-rechargables are quick to replace but you have to buy more over time.

With this in consideration cheap electronics typically come with alkalines AA/AAA because it's cost effective, provides the needed power and decent runtime and they don't care too much about you needing to replace the battery when it's discharged.

> To get a single-cell battery

Strictly speaking, a "single-cell battery" is an oxymoron. The word "battery" means a group of things working together so, while a 9V battery is a battery of six cells, a AA is one (electrolytic) cell and not a battery.

The word originally comes from batteries of guns which were used to batter down fortifications.

1.5 volts is too small a voltage to do most things. AA, AAA, C, D batteries all put it 1.5v per cell because of the chemistry involved. Things that use lithium batteries actually do often just use 1 cell sometimes because the chemistry of them puts out about 3.7 volts. Same with things that use 9v batteries. 9v batteries are actually lots of little 1.5v batteries (watch battery size) stacked up inside that case.

Also, a single alkaline battery at 3v, if in the same form factor as a AA batter would have double the voltage, but half the capacity. You’d still want two batteries.

Essentially, 1.5v is a legacy voltage that we keep. Higher voltage, assuming same chemistry, would be at the expense of capacity, assuming the form factor stays the same.

Or simply put, watt-hours would be the same regardless.

Strictly speaking, no its not because the words meaning has changed over time, as language often does.

Understanding the origin of words (etymology) is great! Not understanding that new meanings aren't strictly bound to older/other usages is not.

Word

It’s also super cheap and easy to do. The one exception I’ve seen is my older Apple mouse, where seemingly for aesthetic reasons the batteries are in parallel ( Also means you can take one out at a time to charge, which is kind of nice but mostly pointless at the same time)

And yet I’ve used products that did exactly this. Remote control cars use multiple single batteries that are wrapped into one useful mega battery.

I'm sooo going to akshually people with this when the opportunity arises. Or even just out of the blue.

They do, 18650s range between 3 and 4 volts

You absolutely can, but by now it's standardized that A-series batteries (AA, AAA, even AAAA) will put out 1.5 V, same as C and D batteries. It's societal inertia that prevents it, nothing else; why change if it ain't broken?

Button cells, however, commonly work at 3 V, and are standardized at that voltage.

The Lithium cells are rechargeable (typically) or are very specialised single use.

The chemistry of cheap single use cells is based around 1-2V. I'm sure there is some chicken and egg problem where cheap cells could be developed with a higher voltage, but typically higher voltages involve batteries of tried and tested cheap cells.

Iswydt

Voltage is derived from chemistry. There is an electric pressure associated with different reactions, and a battery is a device for creating a lot of this pressure in parallel. The basic reactions tend to produce something in the area of 1.5 volts. This is normal for alkaline batteries, the sort you are used to.

The devices we power with those piles usually need more power than this. My knowledge of this is very dated at present, but it comes down to the kind of transistors in the chips. You get about 3 volts out of 2 batteries... Roughly 5 volts out of 3...

The only people who correctly use batteries are Philadelphia Eagles fans who used a barrage of "cells" in their battery.

That's interesting because I have two wireless mouse. One of them requires two AA batteries and the other one requires one AA battery.

So if one mouse can work on 1.5 volt why can't the other one, given its basically the same product.

I recently saw a picture of the insides of a 9 volt battery and, guess what, it contained six AAA batteries.

My Samsung TV's remote has the batteries arranged vertically

What? No.

https://en.wikipedia.org/wiki/Button_cell#Electrochemical_system

Lithium button cells operate at 3V, most other chemistries operate at around 1.5V.

The voltage is the chemistry, you can stack multiple layers (button) together to create higher voltages.

Because having half of increments is useful. We might want 4.5 volts.

This is erroneous. The term “battery” itself refers to doing just this. It is a battery (array) of cells.

This is correct.

In the industry, it’s called a “cell”. The term “battery” refers specifically to arrays of them.

A group of artillery guns are a battery.

I have a logitech wireless mouse my friend got me for my 19th birthday. 14 years later ive changed the battery 5 times

> "diversitility"

That's totally not a word. But I can see how it could be. I can just imagine Frigidaire or General Electric or someone coming out with a whole ad campaign about the diversitility of their products.

But then you need a special battery for a special product. But I can use AA or AAA batteries in a bunch of stuff. If something needs 6v? They require 4 batteries. If they need 4.5 V they can just use 3.

Different electronic componets operate at different voltages. If you use only 1.5v components you can build a mouse that only needs one.

I never wanted a wireless mouse because I figured I would always be changing the battery..it's insane how long they last.

I mean… if there was really widespread demand for it, you could make something AA-cell sized that is actually two smaller 1.5V cells stacked in series. That’s basically what a 9V battery is, it’s six little 1.5V cells packaged up.

But most things that want 3V or more have enough space to hold two or more AA or AAA cells. So there just hasn’t really been enough demand to make a new widespread size+voltage format for consumer usage.

Or you could step up the voltage to 3V (or 5V or whatever you need) internally. But these days you can probably get stuff like Bluetooth/wifi chipsets that can run on very low voltage for exactly this kind of usage.

> very specialised single use.

You mean coin cells. CRxxxx coin cells are all single use Li-MnO2.

>To get a single-cell battery to spit out 3V, we'd need to find new battery chemistry -- new substances that would spit out 3V.

Lithium-ion cells have entered the chat

Fairly expensive in terms of energy density. The alternative are silver based. If you're using a watch for a year or two it shouldn't make much difference.

Chemistry. The chemical reaction which releases the electricity generates 1.5 volts.

That said, have you ever opened up a 6 volt lantern battery? You will find a bunch of AAAs in there wired together to produce 6 volts.

Cells. A group is Cells form a battery.

A 9V is a battery of 6 1.5v Cells.

A AA is a 1.5V Cell.

Yeah its been a nice surprise. Great bday gift

Sounds like something you'd hear said about the Rockwell Retro Encabulator.

Amazon Fire remotes are vertically stacked as well.

How can this NOT be a word? Also, dibs on that for my rap name

Even in remotes where they are physically side by side, they are often electrically connected in series.

If I only had an award to give!

> Strictly speaking, no its not because the words meaning has changed over time, as language often does.

Which is not the case here. It may be common parlance for the layman but they're different for people that use them in industrial settings and they're different according their definitions in the dictionary.

So he's correct. Speaking strictly, it's an oxymoron.

This is really only a thing with devices that take low voltage consumer batters (AA, AAA and the like) for reasons already described. There’s tons of devices with a single battery, sometimes an embedded one and sometimes removable. My camera, for instance, takes a proprietary battery and has its own charger. My phone and laptop have an integrated battery. I have a lot of devices that take a single small button cell batteries that are used in watches. I have tools from an electric screwdriver to a leaf blower that all take single proprietary batteries.

I’m a drummer. I batter things. I don’t have enough brain cells to understand all this technical stuff.

Can it be done, yes. Has it been done, yes. Is it worth doing in most cases, no. Lots of devices have been produced that used proprietary batteries. And they are a pain. I had 2 different wireless land line phones that used different battery packs that were basically 2 or 3 batteries wrapped together. I had to special order a new battery each time. It is much simpler to just use multiple standard batteries.

You can buy lithium AA and AAA cells from Energizer.

Exactly, and alkaline cells far preceded Li-ion cells. You could easily make a TV remote today that takes a single 18650 Li-ion cell, but not in 1980.

Since AAA cells have been ubiquitous for decades, and that's what consumers have come to expect, it's going to take a long time to transition everything to something else.

Again no, strictly speaking he is not. Layman’s terms are just as valid. They do not stop having meaning just because someone uses a term in a technical fashion in a different manner. The usage of the term battery to refer to a singular item is not remotely an oxymoron. It’s a well defined, well understood, broadly used term that is fully consistent in how it’s used.

What do you think the phrase "strictly speaking" means? And how often are laymen talking about the cell count in a battery? I wouldn't say the topic is broadly discussed by the general public at all. And in cases where it is the definition and understanding indeed dictates a single cell battery an oxymoron.

I know it doesn’t mean “I’m going to arbitrarily ignore other definitions of the word to focus on an outdated and/or narrowly used definition”

Again the use of battery to denote a singular object is well established and 100% valid. You can’t ignore the most common usage to try and create a false oxymoron. That’s like saying “Well if you ignore all the points the other team scored, technically I won, even though the final score was 100-1 then”.

> “I’m going to arbitrarily ignore other definitions of the word to focus on an outdated and/or narrowly used definition”

There's nothing arbitrary about it. The definition isn't dated or narrow, it's properly specific.

>Again the use of battery to denote a singular object is well established and 100% valid

Yes just as a truck is a singular thing, that is made up of other things. Nobody is arguing different.

> You can’t ignore the most common usage to try and create a false oxymoron

How often are you speaking of the cell count on batteries to alledge what the most common usage is?

And again, what do you think strictly speaking means? Might it mean according to the strictest definition?

You are not using “the strictest definition”. You are using an arbitrarily chosen definition to justify your argument while ignoring other more common and equally valid definitions.

Oh you have a stricter definition. Let's see it.

There is no “stricter” definition. That’s your problem. You are trying to be pedantic about something that doesn’t apply.

I’ve heard they are actually AAAA batteries which are slightly shorter.

Are you arguing that more constricting parameters doesn't equate to a stricter definition?

I stand corrected! https://www.rfcafe.com/references/electrical/aaaa-cells-inside-a-9volt-battery.htm

When it comes to defining whether the meaning of a word is valid or not yes, absolutely you can’t have a “stricter” definition because it’s a binary operation. Either the definition is valid or it’s not.

Battery as a single object is a valid definition. It is, to use your language, strictly valid and just as strictly valid as other accepted and used definitions.

You are, ironically, confusing definition of words, with definition of situations.

Open up a 9v battery and tell us whats inside

Well, have close to that right now. Lithium cells put out 3.7V nominally.

Good thing in this case validity of the use of the word wasn't in question since it was prefaced with "strictly speaking".

Very small gerbils running in a power generating hamster wheel?

Its 6 mini 1.5 batteries

A miniature universe with a planet inhabited by intelligent life who use kinetic devices to produce electricity which is rediverted to the little round button things on the end of the battery under the guise of "waste power"?

Yeah thats whats inside every battery. Its like those little galaxy things from Men in Black

A single, tiny Keanu Reeves, covered in slime, with weird biomechanical wires attached to his back and scull?

3 3V batteries in tandem?

A bunch of 1mm tall dudes in hard hats and yellow safety gear, running around driving little miniature forklifts carrying pallets of electricity, and when I peel back the sides of the battery they all start yelling at me in thick bronx accents, threatening to get the union reps involved?

Another, smaller 9V battery?

I KNEW it!

This is how 9v batteries are made. And most batteries with higher voltage outputs.