How do you know it never tripped? You believe that, but…
Typical overdischarge detection voltage for a DW01A (most common single cell protection integrated circuit) is 2.4±0.1V.
Lots of simple/inexpensive FET + linear regulator or FET + resistor flashlight drivers do not implement undervoltage protection basically because there's nearly no need for it. The reason is in the nature of the load: as a rule of thumb, 1S emitters barely draw current below ≈2.5V, and on top of this a tiny drop in the FET + regulator/resistor is due also. Hence, probably below 2.7Vbatt the drain is already small/ultralow, and it further drops as battery voltage gets lower.
All of this being said, probably some of you may disagree but, for flashlights with the aforementioned simple FET + regulator/resistor driver types protected cells are not a must, in my opinion.
Well, if it tripped, then it would have to be manually reset, based on what you guys wrote earlier, either by attaching to another cell or to a compliant charger. I was able to check the voltage with DMM, so my assumption was that it was still working, otherwise the DMM would have shown no voltage until you reset it, correct?
According to mtnelectronics, overdischarge voltage protection is supposed to kick in at 2.75V on this cell.
Here is a link to a thread by HKJ some might find interesting if they are uninformed about what a protected cell is. How to see if a battery is protected
You know Barkuti, when I first began this ( apparent quest to spend all my money and go broke . :person_facepalming: ) several years ago; I would have thought you were crazy & had a death wish. That would have been because I knew exactly nothing about LiIon cells.
Finally, after learning a little; I realized that with a little common sense & care taken when using and charging the cells…. I don’t need or even want protected cells anymore for the most part. There might be some instance where I do, but I really can’t think of what that would be at the moment.
If the flashlight has low battery warning and the battery has the protection circuit on it, with that combination give you extra protection? Does the protection circuit draw current while resting?
It does, but very little. We are talking 10 μA or so. It would take a few decades to completely discharge a battery at this rate. More info on HKJ’s page… The Anatomy of a Protected Battery
I was reading up on the charging process. The manual said don’t charge in high heat or humidity. I wasn’t sure if heat generated from the charger, combine with heat being summer will make the battery to get hot enough to trip the protection circuit or have an effect on the battery.
It might or probably even does in some minuscule way we will never even know about unless we did in-depth research of some high level scientific type (which we won’t… ).
I think mainly they are saying don’t have your charge charging in a sauna or a bathroom when taking a hot shower. Or probably best not to put it in the sun on a hot summer day.
They are just covering their bases with those instructions. Just use common sense and all will be well. :+1:
