Miboxer C4-Plus Released on Amazon, BLF members enjoy 30%

Ordered from Germany but do you plan to sell it on Amazon UK?

I’m a noob when it comes to rechargeable batteries, and I’ve been looking at chargers for them, something for an Xmas present. I’ve been looking at chargers off and on for a year now, and finally settled on the Miboxer C4-12, until I seen this C4 plus.

I’ll proabbly mainly be charging 18650’s, I use a flashlight a lot at work, and they will mainly be for that to start. (I have to pick out a new flashlight too, but first a charger). I know I can get a cheaper charger that doesn’t have as many features as these two, but I am set on one of these, just in case I start getting more into it in the future.

My question for you with all the the experience, between the c4-12 and the c4 plus, which one would be better for a noob like me?

is this 2.5 amp, all 4 slots at the same time?
or up to 2.5amps for less than 4?
Also $36.95… thats the promo price for blf, or ………?

Ordered it this morning and it was $25 and change.

Add it to your Amazon cart. Click on cart and you will see a coupon. Click the coupon, then go to checkout and the coupon will automatically apply and lower the price.

As per the original post:

thanks for that

It’s mainly a speed difference. When charging 4 cells concurrently, the C4-12 will be able to charge them faster.

Other than that, the C4 Plus supports additional chemistries and additional (longer) cell sizes.

I’d like this level discount on the C4-12 !
Amazon shows that the C4-12 does support a couple 700 series batteries…

Can you list this on the Amazon Australia website or on Aliexpress with the special discount code? Australian customers cannot buy from other Amazon stores around the world.

This looks like a nice modern charger that can accept the longest protected 21700 batteries…

Seems like an improvement to the Miboxer C4-12, with just slightly lower charger current (C4-12 handles 4x3A, while C4-Plus handles 4x2.5A) but 2.5A and 3.0A charging time shouldn’t differ too much except maybe when charging those high capacity 5000-6000mAh 21700 or 26650 cells, right?

Max on the C4-Plus is 4x1.5A, or 2x2.5A.

One thing I noticed with mine is you can set the charge rate but it never charges at that rate. It’s always substantially lower then it drops rather quickly. Then the last 10mah takes forever. Shows a charge rate of a tenth or lower. Still seems like a good unit. I have plenty of batteries so I don’t have to wait on the ones charging. I know it’s designed so that it protects the batteries.

Is this describing one feature, or two?
How does it work exactly?

Me too, Please share the code

Is that with a high IR battery?

For batteries that have around 30mOhms or less IR, they finish charging quite fast on the Miboxer C4-12.

I think the lowest charge current I’ve seen on the C4-12 is 0.05A (or was it 0.04A) before it completes charging for that battery…

The new C4+ seems to be having some odd behaviour. According to its manual the maximum charge rate is determined by the internal resistance. So far so good. But when you put in a 18350 high current battery (e.g. Vapecell / Aspire) the C4+ would charge it with insane 2.5 amps, i.e. 2.5-3C! Of course, you can set it to a lower value manually but I would rather prefer it the other way around in order to avoid cell damages due to improper charge rates.

Another important fact is that LiFePO4-batteries that must not be charged with the standard profile (3.6V instead of 4.2V) may be at risk when you encounter a sudden power outage without any supervision. Once power is restored the C4+ would automatically start to charge the LiFePO4 battery up to 4.2V, i.e. there's an immanent risk of explosion. I am aware that this is probably a design flaw on more or less any chargers that can handle both 3.6V and 4.2V. Anyway, it's something that should not be disregarded when charging LiFePO4 batteries.

I believe that is a “normal” behavior because of the low IR of the Vapcell/Aspire 18350s. Since it doesn’t “know” about what type of battery, other than it has low IR (indicating high-drain capable cells that can accept high charge rate), so maybe it’s assuming this is something like a 30Q or VTC6 18650, which can be charged at high charge rates… Although in your case, it’s a high-drain smaller cell, so the charge rate cannot be too high. Perhaps charger manufacturer can also mitigate this by testing if it is a short battery, then even though it is low IR, the charge rate shouldn’t be automatically set too high?

Thanks for pointing that out about LiFePO4 batteries and automatic charging. I don’t have any LiFePO4 batteries yet, but will need to keep this in mind for automatic chargers. Maybe charger manufacturers would think of something to mitigate this kind of thing happening?

I wouldn’t call it odd. It works as designed, meaning it sets the charge rate solely based on IR, and not based on the cell’s capacity. This is why it’ll charge a 26650 and an 18350 with the same current, if it detects the same IR on both. For a low capacity cell, this is not optimal, as you noted.

Some chargers have a sensor in the slot slider, so they can tell if you inserted a smaller (shorter) cell, and will adjust max charge rate based on that, but C4+ is not one of them.

Thanks for sharing your thoughts @d_t_a and @Pete7874! :THUMBS-UP: I agree that - with regard to its specifications - the C4+ works properly. However, if a charger is advertised with words like "safe and secure", especially in conjunction with its automatic routine, the average person may expect to rely on the automatic mode. I see a lot of potential for optimizations. If there was some kind of a "resilience sensor" in the charging bays to measure the physical battery length it might help to avoid erratic charge rates on small-sized batteries. Moreover, the charger should never restart charging cells after a power outage (with the standard Li-Ion profile 4.2V). I like the way SkyRC does this on the MC3000. Before charging actually starts, you need to press the button.