Confused here about triple a batteries. Can someone tell me why in a 3 battery cassette why one battery is opposite the other two with regard to pos/neg and how does that work. My guess is it might have to do with parallel and series but not sure. I don’t understand in that if one places a neg battery against a positive that it would have a melt down in my thinking but it doesn’t and that’s one of the things confusing me.
The 3 batteries are in series. Which means the positive end of the 1st battery is connected to the negative end of the 2nd battery, and so on. By packaging them in alternating directions, you can get away with very short connections between adjacent batteries (you’re basically folding a line of 3 batteries into a Z). It’s not just limited to 3-battery holders. Most devices that take 3 or more AAA or AA batteries use alternating directions for the same reason.
They are probably in series because something in the device requires more than 3 volts. Two AAA batteries in series will generate 3 volts when new, but drop down to about 2 volts towards the end of life. It’s possible to boost voltage from 2V to 3V, but it’s cheaper (for the manufacturer) to make the user buy 3 batteries.
It will simply be easier to wire them in series that way, if what you need is 4.5 volts. Simply connect the tail end of #1 to the head of #2 and the tail of #2 to the head of #3. Then the voltage will be between the head of #1 and the tail of #3, which, as it happens are at opposite ends of the cassette.
I’ve had remote controls that take 2 AA or AAA batteries and if the batteries go in side by side, they’re in opposite directions. As stated upthread, it’s easier to wire them in series that way. Did you know if you disassemble a standard 9V battery, you’ll discover 6 AAA batteries inside the shell?
Actually, AAAA batteries…
And, not all 9v are made that way. I’ve seen stacked, rectangular batteries used.
Typically, but not always. I have a Sennheiser G3 wireless mic system, and all transmitters and receivers have 2 AA batts, side-by-side, pointing the same direction.
Apparently the cylindrical ones aren’t exactly the same as AAAA cells - just very close.
I’ve seen the stacked rectangular button cells you mentioned. I’ve also seen long rectangular ones that pack more efficiently than the cylindrical near-AAAA cells.
Perhaps in some applications, you need more amps than volts?
Doubtful. I haven’t checked the wiring (but now I’m going to), but for electronic circuits like this, it’s not likely to need amps. In series, two AAs would be nominally 3 volts, pretty typical for portable electronics. My thought is Sennheiser just wired the batts that way to make it logical. For a $600 package, they can justify the extra 3 cents it might take to align them head to head.
It all depends on the load.
Most of the time it’s better to put them series, for the following reasons:
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For a given power, “higher voltage and lower current” is usually better than “lower voltage and higher current.” This because the latter requires larger and heavier copper conductors, all else being equal.
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It’s easier and more efficient to reduce a voltage than to increase a voltage.
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When cells are in parallel, there will be current circulating between cells. This wastes energy. It can also cause damage to primary (non-rechargeable) cells.
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If a device is designed with cells in parallel, there is a safety concern if a cell is accidentally installed backwards.
Historically small devices required more than 1.5v to power them. Thus it was common for AA or AAA batteries to be flip-flopped in position since this simplified wiring the positive terminal on one battery to the negative terminal on another. This placed the batteries electrically in series which increased voltage to the operating requirement.
The only downside was users had to remember to alternate battery orientation when changing them.
However I’ve seen newer devices using uniform battery orientation, such as the Apple Mouse. In these devices the AA or AAA cells are all pointed the same way. It may be manufacturing efficiency has now improved so the small increase in wiring complexity is outweighed by a simpler battery orientation (although this itself represents a change which users will have to learn).
Another possibility is integrated high-efficiency DC-to-DC converters are now so cheap and and common that designers no longer need a specific analog battery input voltage – the converter can easily pump it up to whatever the device requires, often regulating it in the process. Some LED flashlights use this method.
Using multiple AA or AAA cells in parallel seems like a poor design for a commercial product. If the user puts unmatched batteries (used + new, or different brands with different capacities), one battery will try to charge another. At best it will waste energy, and in the worst case it may lead to a battery overheating or leaking.
And Apple’s wireless mouse. It would even work with one battery, although it would drain the battery pretty quick.