A 10000mAh pouch battery would take up less room and provide more battery life. They are almost as cheap as 18650s too.

walrus01 6 hours ago | parent | next [-]

The neat thing about 18650s though is that you can put a battery door on it and make them swappable, if a person used a holder that can accommodate button top protected 18650 cells. The same cells can also be shared by a bunch of good quality flashlights and headlamps. I have several extremely useful headlamps from "sofirn" that take my choice of cell and have a built in USB-C charging port and charge circuitry protected behing a gasket and twist-open ip67 sealed cap. The pouch battery would be better as an integrated all in one product but also makes the thing a bit less modular.

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iamnothere 6 hours ago | parent [-]

There are advantages in some applications, it’s just not a one size fits all tool. Slim devices aren’t really a good fit for them. They make sense in round devices (like a flashlight) or larger devices where space isn’t as much of a concern.

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DANmode 5 hours ago | parent [-]

Thank you to both solder-nerds for contributing strongly to the thread, please don’t fight.

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walrus01 5 hours ago | parent [-]

No fighting intended, I think it's interesting to see that there's many ways of doings things, and doing a sort of mental whiteboard exercise on what the benefits and drawbacks of different things are... Like, using cylindrical cells would let me share cells with my head lamp, swap cells, independently charge cells and keep spare charged cells ready.

While using a pouch cell keeps the profile much more slim, portable, still has opportunities for really high capacity in watt hours, and allows for a more robust case design that doesn't have the structural weakness of a battery door.

And if you put the pouch cell on a set of wires with a small pluggable connector to the main PCB (and a case that can screw open/shut) it's still an item the user can replace with 5 minutes and a screwdriver if it wears out from many cycles over a period of years.

	▲	iamnothere 4 hours ago \| parent [-]
		> And if you put the pouch cell on a set of wires with a small pluggable connector to the main PCB (and a case that can screw open/shut) it's still an item the user can replace with 5 minutes and a screwdriver if it wears out from many cycles over a period of years. True, and you could even enclose it in a quick swap hard shell case with contacts, like the old Nokia cell phone batteries. (Those are actually still good for some uses, I have a gadget that uses them.) We’re fortunate to live in an era of battery abundance.

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jsisto 7 hours ago | parent | prev [-]

How is a 10000mAh pouch more energy dense than an 18650?

	▲	bri3d 7 hours ago \| parent \| next [-]
		By not having void air space in between cylindrical cells like you'd get with two 18650s? It's mostly just a matter of packaging. Pouches can be made to have better volumetric density than cylindrical cells quite easily, which is why laptops aren't generally full of cylinder cells anymore; the challenge is just providing them enough external support/compression and swelling allowance, which can be accomplished through chassis design.
	▲	iamnothere 7 hours ago \| parent \| prev [-]
		Pouch cells are lighter per mAh due to the lack of metal casing. But more than the casing, the form factor is better for a pocketable device. The cylindrical form factor sticks out, usually wastes some space, and can’t be neatly tucked behind a board or display.