Is it normal for Fenix Torch night battery to drop a lot thru time without use?

Happy Hopping

Happy Hopping

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https://www.thegadgetcompany.com/fenix-tk72r-rechargeable-led-9000-lumens.html

I bought this in Xmas 2019. I charge it about 2 to 3 times per yr., as I only use it as an emergency. I notice the battery drop by itself, not just a bit, but a lot. Just all by itself w/o use, thru time say, in a 6 mth. time frame. But according to the spec., it's Li Ion battery.

Other Li Ion battery gadget that I use, such as cellular phone, doesn't drop like this

today, I charge the battery either the 1st or 2nd time this yr. It only charge up to 92%, then drop back to 90%. So I check online, this battery is at $100

is the above normal? i.e., are they suppose to drop non-stop by itself w/o use?
 
Some flashlights have been nicknamed 'vampires' (draining the battery when not in use). I'm not sure if that model is one such but I've owned one from another well regarded brand that was and it was annoying (in my case there was a workaround to avoid terminal contacts by unscrewing the body slightly).
 
can you give me some details or is there a youtube video on it? does it affect normal charging or normal use?
 
Happy Hopping said:
can you give me some details or is there a youtube video on it? does it affect normal charging or normal use?
Click to expand...
You can find forum discussions about it on the enthusiast communities like Candlepowerforums, etc. Aka 'parasitic battery drain'. It just means a little bit of power is always used which leads to drained batteries over time.
 
I find out how to disconnect the battery just now. That battery is huge. And I can't find any compatible battery online, so only Fenix has it, which would explain the high price. So from this day on, I just loosen the connection and will tighten it back when I need to use it. This will stop the drain
 
Lithium-ion batteries naturally degrade over time and with repeated drain/recharge cycles. They also lose their charge when not in use -- usually around +/- 10% per month. Hence why they require regular charging to maintain 100% charge. Going down to 92% capacity for a nearly 4-year-old Li-Ion battery isn't all that out of line. Manufacturers usually consider reduction to 80% capacity the 'end of life'.

https://www.popularmechanics.com/te...-gadgets-batteries-degrade-over-time-6705747/
 
Apparently I misinterpreted the OP, thinking were concerned about the energy stored had dropped rather than the peak capacity. The former would be parasitic drain if it had dropped significantly (eg: charged to max but months later no energy left) but the latter occurs normally for such batteries as has been noted above (slow decline of max capacity).

For the latter phones take this into account and typically rename the max capacity always to '100%', regardless of whether the actual max capacity has reduced to less over time. Hence why it's not as apparent for phones.
 
but w/ other devices, such as laptop, which also use Li Ion battery if I don't use it, the battery does not drop much thru time. They do slowly drop, say in a few mth. time frame, but not like Fenix, which drops very fast. So say a laptop will drop 5 to 10% in a few mth., Fenix will drop easily 30 to 40% in a few mth. And my Fenix is also a Li Ion battery

Other devices, such as my portable Sony DAC, during Covid, I can't go to the gym, so it's un-used for 1.5 yr., the battery still has some capacity in it when I re-charge.

So I don't know why Fenix has Li-Ion and it drops that fast.
 
Probably just the microcontroller in the flashlight not going into a deep enough sleep or a short on the board. Looks like it is logic buttons to turn it on, means the device is powered. If the system is even using 1mA, it wouldnt even last a year. You would want to reach out to fenix and see what they respond with about this. Could be a defect in the flashlight. Also li-ion batteries lose capacity over time when holding max charge (the ESR of the battery goes up).

Honestly for an emergency flashlight, go with an alkaline based one and just buy a new pack of batteries for it every other year.
 
so now we have 2 theory, a short on the flashlight or "vampire" electronics. The truth is, it's very odd, and I wrote a review after 6 mth. of usage that it drain electricity even I never use it. But since I only use it a dozen to 2 dozen times per year, I don't want to spend $ to ship it to them, as for now, I fix the problem. I also fix the problem if the unit accidentally being on while it moves around in my brief case. So by loosening the unit, it should fix both problem. Now next time I use it, if it's not at 91%, then I know it's the battery. The Li Ion do drop thru time, but it shouldn't drop anything near the extent that I have. We are talking about from 100% to near 0% thru a short period of time, say a few mth.
 
I mean unless I have it on my bench and testing it, all we can really do is stab at air for ideas. You need to reach out to the manufacturer and see what they say..

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