I'm so selfish, i got now 3 of the K18SS for myself, one on my keychain (the finish is holding up extremely well, still brilliantly shiny!), one spare copy in mint condition for my pelican case collection, and another mint one gifted from the Forol Edition. Some retailers like amazon also sell the official K18 accessories like the diffuser (GITD!), extra pocket clip, 10440 battery, and USB charging module. I like the stuff, sharing is fun!!
The charging module is small, made out of SS, and clearly states "3.7V Li-Ion Battery Charger", so it is not for NiMH/Eneloop AAA batteries:
Needless to say, for the charging one needs to substitute the module for the K18 flashlight head duh. The contact disc of the module has a raised plus pole for better connection with flat-head 10440's like some protected 10440's and two or what brass retainer rings for the negative pole. The contact disc is labeled with 'Ultratac' i see. Oh and the 10440 battery has got a blue tube and comes shipped in a clear shrink-wrap to keep it fresh i guess?
The battery has protruding tip, button top, like any other AAA battery. The 10440 is an unprotected 10440:
The label on the battery is "+ ICR10440 3.7V 350mAh -", with no marking of manufacturer or brand. The nominal capacity is 350mAh, the nominal voltage is 3.7V, we'll see about that:
I used my new Quick Charge 3.0 USB wall charger, the BlitzWolf BW-S7, to power the charging module through a short thick USB charging cable (not a USB data cable!). The USB doctor displayed an initial current of up to "0.33A" delivered by the QC3.0 wall charger. The USB doctor is super cheap **** and the displayed values (current, capacity) aren't exact, precise, accurate or whatever but we get the idea. The charging module draws about ~0.3A current and probably also charges with ~0.3A during the CC-phase. That's a charge rate of about 1C, good good:
For this test, the battery had offline a resting voltage of 3.091V (=totally depleted energy). The LED of the charging module turned green after
75min; depending on how early (SOC) you recharge the battery, your charging time will be less than that, maybe 60-70mins! After taking the battery out, i measured 4.153V, which looks like conservative safe charging. The USB doctor displayed "321mAh" as charged capacity (Don't trust this value!).
Since i didn't trust the USB doctor, i also tested the battery capacity more accurately at another occasion with MC3000 (TERMINATION 0.03A,
-0.35A, CUT VOLT 2.80V) logging directly to DEX. Discharging with 350mA is a discharge rate of about -1C. At that rate the average voltage was measured to be 3.6V, and capacity 324mAh, which is 26mAh lower than the nominal capacity:
I also tried to measure the current draw of the K18SS High-mode on this unprotected 10440 battery at fully charged state; with my DMM-in-series measurement technique i got ~"1.05A", so the actual current draw should be higher because of the internal resistance of my DMM. Maybe i should have tested the battery with
-1.05A in the MC3000; in any case another discharge test at a higher rate (TERMINATION 0.03A,
-1.30A, CUT VOLT 2.80V) returned 203mAh. If we take 325mAh as the nominal capacity, then discharging with 1300mA would equal a discharge rate of about -4C. That's imho a bit high for an ordinary Li-Ion cell, no wonder why we got 203mAh capacity only:
On a rainy day i'll retest the battery at -0.2C (=
-0.07A) to see if i get anywhere near the 350mAh specification.
Not looking forward to it yawn, my hobby is so boring.
My old cell results were: 321mAh 3.683V 1.186Wh 04:35:57.
My new cell results are: TBD.
