That is a misunderstanding! The correct, recommended charger voltage is 4.20V and the battery normally is 4.15-4.19V right after charging. I'm sure that HKJ will support me in that
That is correct, but most LiIon batteries has a +/-0.05 volt tolerance on charging voltage, this means 4.25 volt charge voltage is acceptable.
I just had a very cheap charger charge to above 4.4 volt (the battery did survive). This type of chargers makes me think about adding a computer controlled mains switch to my charger test to automatic stop when the voltage gets too high.
After that nasty surprise I have started testing the Lii-100, but I expect the review will be mostly a copy of my Skilhunt M1 review.
Thanks for chiming in HJK!
The misunderstanding was that every charger voltage is allowed that leaves the battery on 4.20 V right after charging.
And now comes the Opus BT C100!
I’m not HKJ, but anyway: +1!
i thought this was an almost well established common sense, no?
I don’t mind being wrong, but why all this hassle over precision within range? The accepted charging voltage is 4.2 ± 0.5, 4.25V is still normal and charges your battery quicker.
As with that, the end voltage also depends on your internal impedance, in case you getting end voltage at 4.20V, that is also acceptable, why would it be considered a misunderstanding? More like a choice, IMO.
Right, I already agreed with you in post #21 
(the problem was: 4.20V is NOT the recommended battery voltage right after charging, but the recommended charger voltage during the CV (end)phase)
Thanks HKJ, sixty545, tatasal, and Pulsar13 for elaborating.
Now, what’s the expected difference between 4.15V and 4.20V in the number of expected recharging cycles?
:evil: Just kidding! I don’t really need to know how many fairies can sit here.
LOL, fairies. Time’s a changing. Li-ion used to go 4.10V max. People would crucify 4.20V-ers then, even when the battery chemistry already could take it. Now these 4.35Vs are getting normal especially in phones, won’t be long before our standards are raised again.
8 years ago, 18650s were slightly over 1000mAh, with ‘fake’ Ultrafires scoring sub 100. Now even UFs are getting steady above 1000 and real ones getting closer to 4Ah now.
My view is, we still get around 300cycles with normal charging within range. Cut that to 100 even, considering aging, faster charge and keeping cells in ful charge. For me, that would still be around another 8 years at least. By which the cycle would have completed again and see more jumps in technology.
So I don’t really mind putting my cells working a bit harder, if that means faster charging (time) and readily available in emergencies. These weigh more to me than getting extra cycle, by which time the end comes, my batteries are really really obsolete anyway.
That’s just my point of view. 
Just got my Lii-100s; cell voltage 4.25V and 4.23V when taken out after being finished for a while. I don’t like that and modded R6 with a parallel 3M, should be 4.15V then, which I like (longer battery life), testing that now.
Thanks, sixty545!
My pleasure! 
I love that charger - have eight now. Made one 50/100 mA and one 200/400 mA, planning for one 3.8 V for storage level.
I no longer worry about cell life.
That’s what I said after passing 8th grade Biology… :GRADE:
My understanding from reading HJK”s reviews is that acceptable Li-ion chargers charge at 4.20v +/.05v not “to” 4.20v so acceptable charge voltages are between 4.15v 4.25v.
I now have 2 Lii 100”s & they both seem to charge at 4.22v (according to my testing) & I have never seen a cell come off them show above 4.19v.
I also have a Lii 500 that also seems to charge at 4.22v & again I have not seen a cell “hot” off the charger above 4.19v.
My Opus BT 3100 v2.2 seems to charge at 4.20 & I havent seen a cell above 4.19v.
My Nitecore D4 shows that it charges at 4.20v & I haven”t seen a cell above 4.18v off that charger.
Cell voltage drops immediately charging has stopped.
If you want to get a few more cycles then marginally lower charging voltage might get you that but personally I want my cells charged as “fully” as possible without being dangerous & if that means losing a few cycles then fair enough.
I use an Amprobe DMM with heavy duty leads & think that it is pretty accurate.
New version of the Lii100 with different cover art and a different revision board. I have not got to test one yet, starting a charge soon to check termination voltage.
Tested 2 now, the terminal voltage is 4.24 volts and the cell upon removal is at 4.22 volts!
Interesting, will wait for the results.
That new Li-100 looks to have Colaier like aesthetics: http://www.gearbest.com/colaier-_gear/
Cheers ^:)
Does anyone know the value of R6? I lost mine when I desoldered it 
It think it said 18D could it be 150k?
Yup, it was 150k ohm stock. I changed it to 152.6K ohm. It went from 4.256v to 4.222v :+1:
sixty545, we don’t have smd resistors here and ordering in some would take over a month and cost way too much. Any suggestions? Can I simply replace R5 or R6 with a specific 1/4 W resistor? (If necessary, I’ll make holes in the body and have the resistor outside…) Charge voltage of a LiIon is just over 4.23V.
Thank you!