Got a new charger-Miboxer C4-12, 4 slot X 3A/slot, total 12A output

Hmmmm…… Thanks for that info about the ‘Auto Default’ being easily overridden tatasal & dchomak. :+1:

That sheds new light on the subject. I had assumed from my reading it was a pain in the arse to override the auto function.

I may well go ahead & get one, because the possibility to charge at 3A is very attractive indeed!!

Thanks again for the info. :slight_smile:

While selecting the charge current manually is easy, some people reported that it does not ‘stick’:

Hmmm…. Thanks for that info Pete. :+1:
It does indeed say that. :frowning:

And, if I am reading it correctly; he seems to say that was fixed on a later edition. BUT the max charge rate was only 800mAh when set manually.

IF that is correct…… that would defeat the purpose for me. The purpose (for me) being able to charge at 3A setting charge rate manually.

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Your not reading it correctly. He said the software on the newer C4, not C4-12, has a max charge rate of 800mAh. The C4 is an older unit.

It’s also important to note that max charge rates are only used below 4v or 4.1v. The charge rate tapers off as it reaches full charge. Texas_Ace used to think the manual charge rates did not stick either, but he was usually just topping of the cells.

jmm244’s issue of the charge rate not sticking on certain cells seems to be caused by the charger reading way too high an internal resistance. When that happens these chargers can act pretty screwy.

I mainly bought my C4-12 to charge my unprotected 26650 cells as they can use that 3A charge rate and it works great for that. It really cuts down on the charge times.

Luckily all my protected button top 18650 read under 150milliOhms (120-145 usually). If they read higher, I reset it and that will get it under 150.

Maybe everyone needs at least a 2nd charger, a more basic one, that can be used for their funny acting cells?

Uh-oh, looks like there’s going to be a fight for that one, if it happens :wink:

The unequivocally positive “reviews” given to the C4-12 charger by some people sometimes bother me, until I remember that I have about 130 batteries that would lead me to the same conclusion, IF that’s all I had. Unfortunately, I have about 70 batteries that drive my C4-12 nuts, and they happen to be among my most robust, reliable and frequently used batteries. My C4-12 absolutely loves the “average” and few crap batteries I have, exhibiting few if any problems with them, even in slot #3.

Although I’d prefer the full manual approach specified by teacher, I’d probably settle for just being able to override a low charge rate on my C4-12 and have it stick. I wonder if they have addressed that problem in later versions of the C4-12 , or if the people who don’t seem to understand that particular issue just don’t have any of the batteries that cause it to show up?

I initially thought the internal resistance display capability of these chargers would be a good way of keeping track of battery ageing, but I’ve been put off a bit after reinserting the SAME battery 10 times within ~3 minutes and seeing readings from 999 to 30 mOhms. Like may other things though, the truth is in there somewhere, and you just have to learn to filter out the obvious crap readings.

Thanks Jason… I sure was reading it wrong. :person_facepalming: … :smiley:

As I have a more than ample number of chargers, that is the reason I considered this one…. to be able to charge at 3A.

And that would mostly be my 26650 cells with 18650’s occasionally being charged at 3A also.

Coming soon: C4-12 v2 ( compatible with Li-ion 4.35V and LiFePo4 cells)

Add discharge/capacity-analysis and you have a useful update.

That would be an entirely different, new model.

hahaha, budgetlightforum, don't forget the budget.

Haha, BLF is no longer “the” Budget Light forum it used to be.

Give us a perhaps sub-$75 MiBoxer quality charger/analyzer, and you’ll give everyone a run for their money.

For those who doesn’t want it, there’s always the regular C4.

I don’t need an analysis feature. I don’t think I need the new voltage settings either.

We were actually talking earlier about removing features from the C4-12 in order to make it more reliable. We all like the high powered charging and all of the 11 or 12 different charge rates, but certain batteries, like button top 18650, seem to read unusually high internal resistance. This can make the charger software act funny. I like the idea of removing the automatic charge rate feature and just setting the charge rates manually. I pretty much set them manually anyway.

Or they can upgrade the firmware to not be too sensitive to high IR from protected cells so as not become too conservative in selecting the auto charging rates.

So far the C4-12’s over-sensitivity in Auto mode to high IR’ed cells is the only main concern of this otherwise superb charger, IMO.

I for one personally like this “Auto” feature very much, specially if the bugs are ironed out ( I only have 5 protecteds, btw, and all high in IR!).

What if the problem is not in the firmware? It could be in the slider design or something else.

In general I agree, Miboxer should focus on getting the existing bugs worked out of the current design before trying to add new features.

+1
If it takes a new model…. go for it. :wink:

well i want a charger with build it flashlight. :stuck_out_tongue: we got many flashlights with build in charger already

Hey guys, I got Mike’s 30Q’s in and they are reading inconsistently. They are mostly under 100 milli ohms, but one is a bit more erratic. I took off the extra wrapper and I ran into a problem.

It seems Mtn Elec button top 30Q are spot welded in 4 points. This should be the most reliable method of attaching a button top and give the least amount of extra resistance, but appearantly it’s not.

Now I’m trying to figure out the best way to remove it without damaging the factory wrapper.

Any suggestions?

Hey, I found the problem! It looks like the spot welds did not penetrate enough. I was able to take a micro screwdriver and pry underneath the tab and it popped right off. That would definitely explain the extra resistance. Now let’s hope the other three cells are just as easy. (EDIT, they were not)


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Well………it seems that this might answer some of our questions.

Okay, after cleaning off both ends of each battery I tested them out in my own C4-12 charger three times each and they all read very consistently with low internal resistance and they all automatically switched to the 3 amp charge rate.

35 47 27
27 34 44
39 43 32
31 33 39

27 to 47 might seem like a big swing, but for this charger I’d say it’s more than fine.

Now to do the solder blobs. I don’t expect the resistance to change any but I’ll test each cell multiple times afterwards just to confirm.