Picture of a disassembled Duracell 9v battery. Below the terminal assembly is a clear plastic case where you can see six sets of stacked rectangular terminals and fillings.
All 9v batteries are just a collection of smaller cells.
That’s the case for anything above 4 V, right?
Different materials used as basis for different battery techs will produce different voltages when the ions go to the anode (something to do with the energy that can gained when the ions combine with the material of the anode being only one of a fixed set of possibilities due to the available free bands in the atomic structure - please check Wikipedia for a proper and correct explanation rather than my vaguelly remembered one) which is why Lithium batteries are always around 4V without extra electronics to drop the voltage (which make them less efficient) and voltages above that require putting multiple cells in series to add their voltages.
As it so happens, the techs for the Carbon-based, Alkaline and Cadmium all have this voltage be around 1.5V (though you might have noticed that the Cadmium ones are a little lower than 1.5V and Alkaline a little higher) so you need 6x cells in series of batteries of that tech to get 9V.
That I know of, there is no consumer battery tech which has a single cell voltage of 9V and I don’t even know if there is any substance or combinations of substances that makes that possible at all.
pretty much, yeah. A 12V is pretty much just 10 1.2V cells iirc
Looks like it’s 6 x 2.25 V
Some are also 6x little tiny aaaa batteries
I actually took it apart hoping to find the AAAAs.
They still have those, just depends on the brand.
Cheap low-capacity 9V batteries are still 6 AAAA cells. The flat cells allow higher capacity in the same space, so you find them in the batteries that advertise themselves as long-lasting.
the little round ones are what i remember when i took a 9v apart when i was a kid.
Me too. Like this.
I used to take apart 9v batteries to get AAAA cells for my laser pointer
Better use of space - they used to be just six coin cells with a load of empty space for a wire to connect the top connector to bottom of the stack
Disapointingly, it came wrapped in a branded metal case that you have to pry apart to see the cool layers.
They need to make transparent ones as a special edition xd
The voltage of batteries in series adds and 1.5V * 6 = 9V, that’s why.
Btw, why do the flat ones (4.5V i think?? use 3 round batteries instead of rectangulars? They could have more capacity due to less space wasted.
It’s cheaper, especially for such a relatively uncommon battery type.
I had an old 12v power tool battery die, so I took it apart to find 8 generic AA rechargeables wired together. I suspect lots of batteries are multiples of 1.5v (9/12/18) because they’re just stacked smaller cells that are already mass produced.
Battery chemistry produces fixed voltages depending on what you use. It depends on where the active components sit on the electronegativity table.
The typical ones are:
Zinc-carbon and alkaline - 1.5 volts per cell.
Lead acid - 2 volts
Nickel Cadmium - 1.2 volts
Nickel Metal Hydride - 1.4 ish.
All the Lithium ion combos - 3.4 to 3.7 volts.
