@tubetime Now I can calibrate my cheap ones!

@tubetime also true of cylindrical cells. An 18650 cell is nominally 18 mm diameter by 65 mm long. AA cells are sometimes called 14500, nominal 14 mm dia. by 50 mm length.

@tubetime WHAT. That's so handy.

@tubetime That works for most batteries. An 18650 LiIon round cell is 18 mm long and has a diameter of 6.5 mm. A 704044 LiPo pouch cell is 7.0 mm thick, 40 mm wide and 44 mm long.

@tubetime What is all this God damned metric shit? 😉

too thick? it's easy to compress it in a vise, like so.

@tubetime I’d wondered!

@tubetime 😮🤯

@tubetime 🤯

@tubetime

I hope you didn't create a short circuit there.

@tubetime @nikcorg
😳 Damn, I always wondered but never checked the origin of the numbers

@tubetime 🤯

@tubetime
Good to know!

@tubetime Be careful not shorting the electrodes!

@tubetime woah, next thing you’re gonna tell me is that 18650 li-ion cells are exactly 18mm in diameter and 65mm long?! 😜

@tubetime ...and it all goes up to 2477 which is a whopping 24mm x 7.7mm and packs up to 1Ah which is six times the capacity of a CR2025. So... If your project demands 3V, but an e.g. 2032 won't last enough... at the expense of some height there are other single cell options. They are less common but they are almost as widely available as the more common ones.

@tubetime
this picture makes me pain because of short circuit the poor cell

@tubetime works for Lipo-Cells and similar too…

i.e. 18650 - 18mm * 650mm

or 26650 is thicker

@tubetime @DosFox yep, same with 18650s etc. diam X length.

Also it’s fun when you don’t have quite the right size button cell but if you do have something that could nominally fit and still make it work!

@tubetime holy cow! This explains it!

@tubetime
For CR type battery coin cells only

The little AG, LR types do have weird numbers related to the manufacturer and chemistry.
4+ different names for same size

@tubetime you can also measure the coin cell voltage with your (metal) digital caliper, just press the “zero” button and you’ll get a reading in volts.

@tubetime Second fun fact. If you measure it like that you are short circuiting it. So only do this demo on a used cell.

@tubetime @vmbrasseur all the vapers know this #18650.

Just like the potheads know 28 grams to the ounce.

@tubetime is it not... shorted through the calipers, when held like that?

well, you probably only did it for a moment

@tubetime 🙀🤯

@tubetime I was just wondering about this a couple of days ago!