Funnily enough my slot 3 some times doesn’t read the cell.
No error it just wont start? It only started happening now.
Have the Miboxer C4, not the C4-12. When charging brand new cells, protected 3400mah cells, cell starting voltage is 3.6 for all cells, all cells charged at .8 amps to 4.20 volts. All charge to around the same voltage but the charging time is a lot different for each cell.
cell 1 3 hours 3 minutes
cell 2 3 hours 17 minutes
cell 3 3 hours 30 minutes
cell 4 3 hours 3 minutes
Why is this happening. Have eight brand new identical cells and it happened on each set of four, same charging times.
In my experience with different brands of chargers, even though my cells are brand-new or hardly-used, there are always occasions when that happens, even with my new Eneloops.
IR is of course always a factor.
Mine began in the same way. Slots 1,2 & 4 the battery would read and select best setting. Slot 3 would start to read, then go blank. I would jiggle the cell and the reading would briefly read, then disappear. I had to fiddle with slot 3 several times before the read-out would display. Only to display a few seconds and disappear again. Then it would not display anymore. It would only say “Err”
Maybe it is IR, these are high quality cells and it seems like the IR would be similar for each.
I’ve had a similar kind of issue with a hobby charger where a particular bay will charge differently to the rest no matter what battery pack I plug into it. Also the issue (for same battery packs) never showed on a different charger. So I don’t think it’s an IR issue rather a discrepancy within the charger. Sad to here so many people having issue with this charger. I recently bought an Adeaska so I’m kinda glad I didn’t end up with a C4-12 but don’t actually know much about the Adeaska reliability.
Well if mine is stuffed might as well pull it apart and see what is going wrong.
Yes please. If you can, post high-res pics of the PCB including part designators and case markings. I’d be especially interested in the SMPS ICs and what I assume are charge controller ICs for each charging path…
edit Never mind the pictures, the relevant ones all seem to be included in Lexel’s review.
I’ve had mine since late October. Knock on wood, so far no issues with slot 3 or any other slot, for that matter, other than the charger rebooting itself after a while due to overheating if I charge all 4 slots at 3A.
This might be a really stupid question, but is possible the software is screwed up between voltages of NiMh and Li-ion?
I only ask because I’ve just opened the C4-12 I won in the MiBoxer competition and spotted that termination voltage for NiMh is 1.48 v.
Just a coincidence?
But why would it only be screwed up on slot 3?
Does output voltage in open slots (without a cell) mean anything? Mine is as follows:
Slot 1: 4.97V
Slot 2: 4.97V
Slot 3: 4.97V
Slot 4: 4.86V
Wondering why they are not all the same. Alas, slot 4 is also used for power bank function, so maybe the added circuitry affects open voltage.
What are you guys seeing on yours, especially those of you that are having problems with Slot 3 overcharging?
My $0.02 & Possibly good advice: Put electrical tape over the poles on slot #3 to ensure you don’t inadvertently put a cell there. If it were me, I think I would discontinue use of the charger completely. Everyone here on this forum knows the dangers of Li-Ion use, more so over-discharging not as much overcharging, but still risky.
It is quite ridiculous that a new charger should have any issues of this sort at all. Mi-Boxer apparently has do QC issues…
Mine was returned so I can not test.
Two new ones are in the box un-opened.
That is about perfect termination voltage for NiMH cells they should terminate around 1.5v. That voltage will drop when the cell settles the voltage should stabilize to around 1.3/// any where around there. Newer cells may sit at 1.38 older cells around 1.32 maybe?
Depending on the age and quality of cell.
I for one learn from the experience of others.
Stumbled across this thread, after recently placing an order for this charger with GearBest. I hope mine doesn’t have problems with slot 3. 
Seeing as how each slot seems to have independent circuitry based on the ability to set separate current and other parameters by individual slot I would expect that any slot could mess up. Minor performance variations would be expected due to component variations. HJK also says slots are independent in his review as I recall.
I note too looking on Amazon apparently the same charger is being sold under multiple brand names. At least two Miboxer chargers are also apparently being sold under the name Kinden on Amazon based on photos and specifications so far as I can tell.
d_t_a just curious, why did you post this same thing twice? and both on the same day
He said one thread was about the charger and one thread was about the battery.