If it's a 'protected' 18650, could be the protection circuit tripped for whatever reason.As the title says, has anyone ever seen this happen before? An 18650, fully charged, used in other lights before,....suddenly acts like it is completely dead. Tried in three different lights. :-/
If it's a 'protected' 18650, could be the protection circuit tripped for whatever reason.
In some cases, that condition will be 'reset' when first installed in some chargers. I've experienced this, and my particular charger reset them.
This!!!Sounds like something wrong with the cell, I would dispose of it.
Just put it in a small sealed bag e.g. zip sandwich baggie to keep from shorting, or if something should leak. Some retail stores here take batteries, not all accept Lithium-ion. Home Depot might, they take regular alkalines etc. butSeems like sound advice.
What is the best way to dispose of one of these cells?
That's what confuses me. That it is showing 4 volts,...yet not producing any output.It's odd that your multi-meter reads 4 volts, yet has no output.
Protected batteries with a tripped circuit will show 0 volts.
I'm assuming you don't have an LED with two leads that you can touch the + and - ends of the battery to see if it lights up.
Just for curiosity.
This is exactly correct. Even the old-school passive VOMs might have an input impedance in the 20,000 ohms per volt range, which is still not low enough to produce a valid test for a batter with high internal resistance.Modern voltmeters have very high input impedance (in this case, the DC resistance component of that is what's relevant), and present almost no load to the circuit under test (which is ideal). The cell in question has a very high internal resistance (due to unknown failure / degradation). Your voltmeter, as it draws practically no current, will see the difference of potential (voltage) across the output terminals of the cell, so it will read the voltage of the cell despite the excessive internal resistance (effectively open-circuit / no-load conditions).