Miboxer C8 charger: unable to manually set battery type to Li-Ion

I can’t exactly remember when I’ve tested the Miboxer C8 with overdischarged batteries (less than 2.0v), but I seem to remember that if the voltage jumps upwards, it should go to Li-Ion mode?

Would you happen to have another charger that can try to charge that overdrained battery to at least 2.0v?

Same happened to me a while back. It starts NiMH then switches to LiIon when voltage gets a bit higher. Keep an eye on it, check cell temp

Thanks for the responses, everybody.

When I realized what was happening, I immediately took the battery from the charger.

Now I tried to put it into the charger again, and it immediately started charging as “Li-Ion 4.2V”… I guess spending a few hours in a shelf was enough to bring its voltage back into a range where the Miboxer C8 was able to immediately recognize it as such, instead of NiCd/NiMH.

One more question: won’t the initial charging as NiCd/NiMH, before it reaches the necessary voltage for the charger to switch over to Li-Ion profile, damage the battery? Wouldn’t it be better to be able to set it manually as the correct type right from the start?

Cheers,
— Durval.

I just grabbed a protected 18350 that was drained way way too low by just sitting around a few years. Stuck it into my Opus, nope, didn’t even recognise the cell in the slot.

Stuck it into my LK 101 or whatever, and it immediately started charging. After it had been going a while, back into the Ope. 3.6V at that point, charged right up.

Figured right that its twin was in the same condition, and did the same. Both Rat Shack “DE” (“Digital Energy”) cells, rated 800mAH on the wrap, both clocked in at the high-800s and low-900s after the first cap test and then a “refresh” (3 cycles down and up).

Point being, sometimes a “smart” charger can be kinda dumb, so use a dumb charger to get it going, then switch over.

Oh yeh, both work fine in my SC31pro with the shorty tube. Hella bright, played with it quite a while, still blinks out 4.1V, so the cells are still good and juicy.

An idea for you. Grab another fully charged 18650, connect it to your discharged cell. pos to pos, neg to neg and let the cell balance for 5 min or so, then pop it in the charger. I’ve done that a few times using a Q8 flashlight. No, it won’t over heat your cell. Especially not a HE4, one of the most robust cells made

Charge voltage is charge voltage. As long as the amperage is low and the voltage is ‘within reason’, it really doesn’t matter what protocol you use. I’ve put them in NiXX dumb charger (very low amps) and let them run for awhile, then put them in an appropriate charger and away they go. Shorting them with a good battery works. This is not precision electronics with an over discharged battery. It needs to be boosted up to an appropriate level to work in the charger.
That said, over discharged Li-on does take some damage with the over discharge. The lower, and longer, the more potential damage. I mark and watch any battery that has had this occurrence.

Hello everyone, again thanks for the many tips.

Unfortunately I don’t have a dumb charger to try and get a overdischarged 18650 cell up to a voltage where the smart charger can detect it automatically. My only other chargers are a smart La Crosse BC700 (can only handle AA/AAA form factors, and no lithium) and a couple of dumb no-brand 14500 chargers (came ‘free’ with a couple of batteries I bought years ago),

The idea of shorting the overdischarged cell with another one in order to get it back up a voltage where it gets correctly auto-recognized by the Miboxer C8 is a good one — I remember doing that with the BC700 years ago, but I did it with the ‘bad’ cell in the charger and then using paper clips to briefly ‘parallel’ another cell on top of it: this way the charger started charging in that slot, and kept going even after removing the ‘parallel’ battery. Would such a scheme work with the C8? If so, perhaps it would be preferable as the ‘good’ cell is used only very briefly.

Anyway, these shenanigans are kinda ‘gross’ — I would much prefer that the Miboxer just did what its manual says it does, and allowed me to select the correct type for the battery manually . Too bad this seems not to be the case… :frowning:

@flashburn mentioned it depends on the firmware. Is the Miboxer C8 firmware upgradeable/moddable? I don’t think so, but it never hurts to ask…

Cheers,
— Durval.

Hello everyone,

I have (bad) news: got another overdischarged battery, this time down to 1.1V (didn’t manage to fix the stupid piece of electronics yet), so I inserted it into the Miboxer C8 and following the advice I’ve received here, I then just changed the charging current to the minimum (0.10A) and waited for it to automatically switch to “Li-Ion 4.2V” when the voltage got high enough.

Well, that never happened: I waited a full 10 minutes watching the voltage climb from the initial 1.1V all the way to 2.30V, and the charger kept identifying the battery as “NiMH/NiCd” on its display, see picture here:

NB: while waiting, I periodically double-short-pressed the [MODE] button to see whether it would allow me to change anything, to no avail; the only response from this button was when I long-pressed it right at the start to set the charging current at 0.10A.

So, it seems clear that there was no automatic switch over to the correct profile; I then turned the charger off, removed the battery and measured it with my multimeter: 2.25V, almost exactly the 2.3V reported by the charger.

I then turned the charger back on, reinserted the battery and voilá, it immediately recognized the battery as “Li-Ion 4.2V” and started charging it, showing a voltage of 2.45V and a charging current of 0.30A:

My conclusion so far: There is sadly no kind of “automatic detection” for overdischarged Li-Ion batteries in the Miboxer C8 (so forget about just inserting the batteries and leaving it to do its work), nor the possibility of manually setting the correct battery type; looks like said “smart” charger simply isn’t, and will treat such a battery as “NiMH/NiCd” even after it reaches voltages that are clearly too high for such a battery.

I’m really disappointed by the Miboxer :frowning:

OTOH, at least it “allowed” me to charge the battery up to a high enough voltage and then treated it right after being turned off and back on, so I didn’t had to resort to any ‘shenanigans’ like shorting with another battery… a lot of manual work for a reportedly “smart” charger, but still better than nothing, I think.

What do you people think (besides, of course, that I should fix the overdischarging stupid piece of electronics ASAP before my batteries go to hell)?

Thanks in advance for your opinions,
— Durval

My C8 works fine charging over discharged cells. The latest one was a 14500 that was down to .8v. Been using it everyday to charge vape batteries for the last 3yrs. I love it, because there is plenty of space for my son to pop in his AA Eneloops for his game controller at the same time I’m charging liion, thus only needing 1 charger on the desk.

What does it show when you put in an overdischarged LiIon 14500, “NiMH/NiCd” or “Li-Ion 4.2V”? If the former, does it change to the latter as the charging advances, or does it stay fixed until the end?

If there is automatic voltage detection, AND it does MULTIPLE chemistries, HOW is it going to know what exactly an over discharged cell is?
I don’t see any problem with it doing exactly what it did. It’s responding appropriately within the parameters it’s designed.

Now….about this problem of blaming the charger for your problem of over discharging batteries…….

I’m not requiring it to detect all possible combinations of voltages and chemistries.

I am requiring it to let me manually set the battery type (which incidentally the manual says it does, but in practice it doesn’t) in case its auto-detection didn’t work.

I do not blame the charger for anything except not letting me set the battery type manually (which again the manual says it should, but in practice it does not).

Now, about your problem of blaming people for saying things they didn’t say… :slight_smile:

I honestly never paid attention. Just loaded the cell in the charger, saw the flashing lighting bolt, and walked away. I’m assuming your charger is working fine. Had you waited for 2.8v, it probably would have switched automatically. Basically most all battery manufactures say, don’t discharge below 2.8v or above 4.2v which is the happy spot for battery longevity. MiBoxer most likely has those two industry standard parameters set in their charge algorithm.

I think you’re bad mouthing a good charger from lack of understanding on your part

Thanks for the clarification.

The last time I did that, I ended up with a totally dead battery — that’s why I’m watching it very closely now.

This can be easily tested, the next time I get an overdischarged battery. I will only set the charging current to the lowest possible amount so as to not run any risks of (further?) damaging the battery.

Not the case with the LG HE4: its datasheet specifically mentions a “standard discharge / low voltage cutoff” of 2.5V, and the number 2.8V isn’t mentioned anywhere (see p.4 of the PDF).

But anyway, I get your point.

It’s a good theory. I will test it in practice the next time I get an overdischarged battery.

I’m sorry you got that (wrong) impression. But if you read what I wrote again (starting with the title: “Miboxer C8 charger: unable to set battery type to Li-Ion”) you will see that my complaint is because, contrary to its own manual, it doesn’t let me set the battery type manually.

EDIT: I’ve now added a note to the original post above to try and make that clearer.

Li-ion vs LFP is bad enough, but imagine trying to charge a NiMH cell to 4.2V…

There’s a reason they wouldn’t want any sane person to do that, at least not with one of their chargers.

(I have to always remember when charging my LFP cells to bap it into LFP mode, not Li-ion, like just last night, in fact. 3.2V from a LFP cell looks like a perfectly reasonable voltage for a Li-ion cell.)

Hi @Lightbringer,

Not sure if it would result in an explosion (NiMH has no combustible components AFAIK, contrary to Li-* batteries), but it certainly would not end well for the cell.

So you think that the behavior I’ve been observing on my Miboxer C8 could be stardard CYA on the manufacturer’s part? Even when the voltage it’s measuring from the battery (2.25V, as I’ve documented) is already clearly out-of-range for the NiMH/NiCd battery type the charger keeps classifying it as?

Yep, I’ve read about that on the manual, and I’ve also experimented with the [Mode] button once the battery is recognized as “Li-Ion 4.2V” and it lets me change it to the LFP mode.

Cheers,
— Durval.

Seems you can set all the channels to do the same thing-right?
Can you put a good li-on in it, set all the channels to the same, then set the over discharged one in it?
My suspicion would be that it would not charge it as li-on, but revert to NiXX if the charge was below something, like 2.0v, certainly below 1.5v.

I can understand the manufacturer creating a safety mechanism that would always revert to the safest charging method depending on the voltage it ‘sees’, no matter what you set it at. It’s also not uncommon for it to stay in that mode. Cannot address the Miboxer since I’ve not used one. To get it out of that ‘safety charge’ mode you probably would have to remove the battery, possibly even unplug it, and start over. It seems that did work for you.

FWIW, I keep some old ‘beater’ cells around just for this kind of experimentation. LiFe cells can be somewhat safely discharged down much lower than li-on, and not go rogue on you when charged.
These cells don’t see active service where a failure would be a problem. Checking out the low voltage cut off in devices is one of their ‘jobs’.

I also simply don’t believe any manufacturer that claims it’s OK to discharge their cell to 2.5v. Looks good on paper, improves the capacity specs, really not good for the cell. That has been shown repeatedly in research.

It’ll still ruin the cell. I had NiCd cells sizzle as they vented from cooking too long. Didn’t burst into flames, but ruined the cells.

Absolutely. If the charger can’t immediately identify the type of cell, why would it hazard a guess and possibly ruin the cell anyway?

Hopefully it doesn’t try stuffing anything more into it, but just sits there doing nothing.

Yeh, worse that happens is that it “charges” the Li-ion cell to only 3.2V or so.

Might make a good storage-mode…

Hello,
excuse me, maybe my intervention is too late, but it can help
For set the batteries type
Put the batteries into any slot, and quickly double press the Mode, then the batteries symbol will flashing, short press MODE, you can switch the batteries type, you can long press (MODE to exit, or it will exit automatically after 5 seconds.
Totopon

Some of my chargers call themselves “smart”. But only one of them is really smart.

The rest of them have a manual, that says: First you choose the MODE, and then the CURRENT.

BTW, given the number of depleted cell’s you write about, isn’t it time to change to protected batteries?