IR reading Miboxer C4-12 vs Zanflare C4

I was charging 4 18650 batteries (various brands including one Nitecore) in my Miboxer C4-12 a couple of days ago. The Nitecore didn’t seem to be charging very fast and was showing an IR of 999 milliohm’s, the rest of the batteries were reading in the low to mid 100’s.

I took the Nitecore battery and put it in the Zanflare and ran the NOR test, it ran and all looked ok with the IR reading about 150. When I put the battery back in the Miboxer the IR reading was 666.

Any idea what’s going on with this?


My Miboxer C8 reads high often too. Lii500 average much lower. Maybe clean all the contacts to be sure.

I like my Miboxer C2-6000 but IR readings are to be ignored in my opinion.

This is very common with the C4-12, especially on protected cells with button top. You can try to wiggle the batteries in the bays back and forth. Eventually, you might get a better reading but usually cleaning contacts (i.e. the terminals on both the slots and the batteries) is all you can really do to improve the situation a bit. Some months ago there was an ongoing discussion about this in another thread about the C4-12. I even had big issues charging unprotected Samsung 30Qs with joint-welded button tops. IR readings were never below 350mOhms even though cells were brand new.

The only workaround I have read in this thread was to override the automatic mode and manually select the charge rate.

Thanks for the responses. I like the C4-12 as well so I’ll take your advice and just ignore the IR readings.

Thanks again all.

I have this same problem with my miboxer c2-4000. It has to be the shape of their rails and not the circuitry.

I purchased “button top” 30Q’s which have a small round point like an AAA battery and thick wrappers and they hovered around 100-350 like you. I have some other 30Q button tops from banggood which have a wide flat plate on the top which I assume makes better contact with multiple parts of the rail and those are consistently low IR, like ~40 or so.

When I top both sets off and test in my Q8 however both perform the same so I came to the same conclusion as you. The batteries themselves are fine and I just override the charge rate.