New Miboxer C4-12: "Upgrade C4-12"

[hrbngr]

So, based on Sidney’s data below, should one be concerned that the New C4-12 is charging brand new, low resistance 18650s on automatic mode? I was particularly looking at the C4-12 due to its’ advanced automatic battery charging, not so interested if I will always have to manually set it. Was this already a known issue on the original C4-12 and I just missed similar feedback on it in other posts?

@Sidney Stratton

Got mine (New C4-12) a couple of weeks ago and tested some new 18650GAs (4x):

Starting charge @ 3.51 V & 1.90 - 2.05 Amps (49 - 51 mOhms).
After a few minutes auto adjusted to 2.45 Amps (all bays)
At the 45 minute mark the current had risen to 3.00 Amps and the temp at 52ºC.
Manually set it down to 1.50 A.
Terminated full charge within the hour, ~31 mOhms IR

Nice to be able to set all 4 bays in a few clicks. Weary to let the charger auto select current on low impedance cells; never had cells that hot (the charger has an upper limit; current throttling at 60ºC, 70ºC cutout).

Quickest time charging but at a cost of stressing the cells. For all the trouble in getting these 4*, I’d like to have the most life!

[BlueSwordM]

Same thing with the C4-12 V1.

Not a bad thing, but the automatic charger is not very conservative in terms of charge rate.

However, it’s been wonderful as a charger, so I would recommend it to most members here with a manual charge rate.

[hasddie293]

I have this Version 2 C4-12, I let it automatically charge my Vapcell INR21700 4500mah 20A RED…first it start low current and for while it increase current. I noted that it goes Max current which is 3Amps, that when I see temperature reach 40 celcius… Before, my thought is that charger than can determine battery chemistry, Internal ohm and auto select current accordingly should be safe for the battery condition and life cycle.

I’m doubt about the battery condition when it reach 40 celcius. I know 60 celcius is limit for baterry life cycle. The charger charge fine though as ussual terminated at 4.20v, trickle down current fine, no big issues actually here just saying…

Next time charge I should charge manually, my question is how much current should I set for my newly Vapcell baterry?? 2.5a? just 2a? I was try not to reach 40 celcius, it safe though but I want just way below that threshold.

Or should I leave it automatically incase I am wrong here…hehe. I’m just getting skeptical on battery…funny…

[Sidney_Stratton]

As a postscript to my earlier observation (post #54), I’ll be manually setting the charge rate. Best guess depending on cell - low side to extend battery life.

[lacrimal]

@Mishanchik

Interestingly, fixed MiBoxer problem 3 slots in the Upgrade C4-12?

Old C4-12 - problem (reviews from BLF)
C4-Plus - problem (reviews from Aliexpress)
C4S - problem (reviews from BLF)

I want to understand - did the MiBoxer engineers work on the bugs, or their problem of the updated C4 series was transferred to Uprgade C4-12 also.
Apparently the quality of products is affected by the fact that it is produced in very small batches.

Hi,

I can confirm that faulty port #3 looks like faulty port #2 now, like in this video https://www.youtube.com/watch?v=M3B4h6MSB4Q. Also saw user D T A posted information here slot #2 error on "Upgraded Miboxer C4-12" (got replacement unit..)

I am a victim of this too (same symptoms, 12V on slot #2 when empty, Err message). Three confirmed faults in above link, add 2 of my friends who bought this device from different seller on AliExpress with same problem. This is mine https://www.youtube.com/watch?v=pOXWayT7X8g

Cheers