Reply To: [unofficial weekender] 3 weeks until Christmas 2020

[blinky465 17028xp 0]

For a single green LED, it really should be (is it a round button type CR2032 or CR2016 or something?). Is your battery fresh? Is it one of those 10-on-a-card-for-a-euro jobbies, or a proper branded battery?

You could aways put a resistor inline (about 220 ohms) and that’d let you power it through a 5v phone charger or three AA batteries in series. If you’re connecting more than one LED, you’ll probably need some clever electronics, since they all have different voltage drop and you can’t just wire them all together in parallel (in series, maybe, but they you’ll need a much larger voltage to power them).

But a single green LED *should* light up from a CR2032 just by pressing the legs to either side of the battery.