The MiBoxer C4-12 charger seems to be a promising charger so I decided to take a look at it.
The links here mostly point to the MiBoxer C4-12 from Amazon store, but since Amazon does not ship (or would be too expensive to ship) to my country, I instead looked for another seller from AliExpress.
I just got the package and was testing it since a couple of days ago.
But today I got the biggest surprise, it overcharged my precious INR18650-30Q to 4.48v!
I only recorded the video of the display after it display 4.48v (as evidence):
similar video with multimeter to check the overcharged voltage
I suppose MiBoxer brand still has a lot to do even if it "occasionally" overcharges only.
(to be fair, the past 2 days, I have tested charging maybe around 8 batteries already from various states of charge, and they seem to have charged properly; but today's overcharging is simply totally unacceptable).
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.
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.
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”
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.
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.
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…
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.
