The price - performance ratio of these unprotected without standard without protruding positive terminal provided quality batteries I see as excellent.
The self-discharge rate falls even after months of absolutely negligible.
The voltage curve and the high current delivery apply in these Panasonic batteries as exemplary. In which voltage range the high capacity is delivered linearly, so that the term an LED flashlight with high luminous intensity as long as possible fails, I can not see from my side.
Please use this battery only in equipment / flashlights with electronic control, battery warning at too low a voltage, shutdown, etc.! Otherwise would be greater care as regular measuring the voltage of benefit to harm the batteries rather than by deep discharge permanently and prevent possible overheating, or fire.
Not permanently leave the battery in charge in a rather inexpensive charger it but after loading end and possibly even nachgemessener final charge voltage of max. Necessarily refer to 4.2 volts from the device. If the charger load significantly higher than this value - approximately to 4.3 volts, this is probably faulty, not reliable enough and should best be replaced.
The critical area for complete discharge of batteries of this type chemistry and is falling at values from 2.5 volts. For safety reasons the voltage as far as possible should not be less than 2.8 volts come until the next charge. This is mainly a long durability as well as the storage of unused batteries below 4.0 volts and not under charging voltage.
It is not self-explanatory on the battery or the product-disclosure if it is to a protected or unprotected version with low - overcharge protection concerns, is with or without protruding positive terminal. The current product picture is in this respect also not suitable. How is that recognizing this relatively sensitive and may not immmer hazardous battery type immediately in the field a beginner.
The batteries offered are therefore not (Top Button) protruding but flat positive terminal, which excludes the use in flashlight with integrated reverse polarity protection.
The counterpart in the direction of light head should have a spring so that these batteries have contact. I can say with certainty which of Fenix TK15, TK22, TK35. Do not work specifically NiteCore P15, P16 and just many other.
Thank you that you have read this far in the hope I could contribute something to your purchasing decision or general informational content.
I would be very happy if you rate my review "fair".