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Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@DrAzzy
Most 18650 cells do have protection circuitry in them, even those el-cheapo cells from china that have 1/3rd to 1/5th of their rated capacity - not that you should ever rely on that... I once shorted an 8s3p config of Ultrashit 18650s, rated for 6000 mAh (1200-1500 in reality). Blew every fuse, and then I measured the battery voltage - ZERO. I took the cells out and was measuring around, and as I was doing so, one at a time, they turned themselves back on. Batteries have been in service since. HOWEVER I'm not sure what kind of protection the "high-draw" ones have, because they can't have much in the way of current limiting if they're going to supply 30A... (though I do suspect they have overcharge protection). I would never charge a single cell LiPo without an appropriate charging IC - on the principle that the cost of doing it right is low. When I have to do multi-cell configurations, though, I use a current limiting charger and charge them in series, since I haven't found any nice balancing charger IC's yet that I can build into my projects (open to suggestions, particularly for a 4s configuration)
LiPo batteries are "rated" at 3.7 or 4.2v - despite having the same discharge curve. You charge them up to 4.2, but the discharge curve has a long flat plateau at 3.7v. I use the ubiquitous nitecore charger for 18650s (the cheap ones, and my friend's high draw vape batteries), when I'm not using a built-in charging setup.
That said, the whole point of this charger, as it looks above, was to continually cycle the charge in the battery?
That was necessary with old NiCd batteries, which had a very pronounced memory effect, but is not necessary in NiMH batteries. And LiPo batteries are best stored long term at around 60% charge, and do not have a memory effect, so this charger would be entirely the wrong thing here (not to mention it would take eons to charge any decent sized LiPo battery at 20mA....).