I tested the IR of my unsused, brand-new Samsung INR18650-25R. No rolling nor pressing of sliding negative contacts on all occasions, just pulled back cell to lose contact then release.
The Miboxer C4-12:
Vapcell S4+:
Hi Henrik,
Nice to see you around here with us as always!
The right-side mounted Manual or Auto Charging Mode selector.
Will manual charging allow a lower storage charge termination (3.6 ~ 3.7 v) to be set?
slmjim
No, manual/automatic is only related to current selection.
I realize this charger does a lot.The things it does not do are important to me.
Another negative in my book is it can Only discharge “Two” batteries[Slot 1 and 4] at 1 amp.
I test Four batteries a lot. Doing them at 500mAh will take twice as long.I do not understand why?! It can charge all 4 slots at 3A yet it can only discharge Two batteries at 1 amp!
Nice!
tatasal Could you do the same IR test with the Zanfare C4? That one was supposed to have fairly good IR accuracy, yes?
During charging most of the energy is being put into the batteries requiring a big enough power supply that can do so. During discharging all the energy from the batteries is being dissipated as heat thru a resisitor or resistors. Its a matter of how much energy that can be dissipated for its size. 4.2 volts at 1 amp x 2 basically it can get rid of 8.4 watts of energy. The more energy that has to be dissipated the bigger the components and heatsinks has to be. I brought this up in the BLF designed charger thread. The making of the BLF UC4 charger: the start of a new venture, INTEREST LIST, UPDATE 7 (Well, ramping stopped :/ ) - #141 by moderator007
Its a matter of fitting everything needed in one simple unit without it being a boat anchor. Sacrifices have to be made. To me switching to a aluminum case would improve alot of the design for getting rid of heat and energy increasing discharging current but some dont think a conductive metal case is safe even though every hobby charger I have ever owned used a aluminum case that is isolated electrically. Just my two cents 
.
,and….doing a 4 x 1a discharge will also require a fan…which made a lot of people complain with the Opus because of the noise it emitted.
….and….nowadays most do want faster Charging capabilities as cell capacities and sizes keep going up.
Oh well…
So this could be a replacement for the Opus BT C3100? Or would it be an upgrade from the Opus?
Well, to guys who do a lot of niMh ‘refresh’ or ‘capacity’ test, the Maha Powerex MH- 9000 is more appropriate, which l also use.
But in my case that l never ‘refresh’ my lithium-ions (since it will only hasten its demise), the answer to your question is yes.
How annoying is the bell reminder when the battery is charged?
How well does the auto mode really works?
I have not tested to a fully-charged cell yet so I haven’t heard it yet. So far what I heard is soft, pleasant sound upon plugging, so I don’t know if the sound is the same or not.
Comparing this charger with my other charger that features an Auto mode (specifically the Miboxer C4-12)…most times with the C4-12 I get to change it into the Manual mode because it is very inconsistent in IR readings which run into the hundreds regularly. As you know with these Auto mode charger, the higher the IR the lower the charging rate, so low that it will only charge .3A.
The Vapcell S4 has so far not shown to have the C4-12’s usual inconsistent mistaken high IR readings and will charge at a much higher rate in Auto mode.
I know all about the C4-12. Worst chargers I have had in my hands.
Thanks for the clarification Tatasal. Might keep an eye on this one as a second (in reality 5th ; ) battery charger. Thanks for sharing.
In Auto mode does it use different currents other than 250/500/1000/1.5/2A?
I assume you are asking about Charging current:
In Auto mode, current is dependent on the cell’s IR…for example, the 25R I just tested had 21mohm and it chose 2.5A… it will go as high as 3A if a lower IR’d cell is used.
In my C4-12, the notice as the cell is going up in voltage, it IR goes down and as such, the charging current also goes up. I have not observed this yet in the S4 since I have not tested a cell from a fully discharged state until its full.
In Manual mode, current is adjustable from 250, 500, 1000, 1500, 2000, 2500 and 3000ma. X 4 or any combination per bay/cell, as needed.
If it can’t be manually set to 3.7v to discharge and store cells, or charge to 4.35v, then I certainly wouldn’t consider it an upgrade to the Opus.
The S4 does not have a Storage mode, nor 4.35v termination voltage.
Actually, personally I don’t think getting the cell off a charger when it displays 3.75 voltage is a proper storage process. ( though it won’t hurt!)
Why? For people who also own a hobby charger like myself, when I use the Storage mode of my iCharger, the Storage process is done differently: Once the 3.75v is reached, the charger exists the CC stage and goes into the CV stage as the current steadily goes down till properly termination. The portion from CC to CV takes still takes quiet a long time still (IIRC perhaps 10min?) and keeps on adding more mAh until it finally terminates.