MiBoxer C4 -- 36% OFF promo at our Amazon store

Just bought one … Many Thanks for the heads up. Great charger.

Free shipping to Australia: https://www.gearbest.com/miboxer-c4-12-\_gear/

Ordered, tnx!

Was going to suggest, even easier to find would be to use the link in your signature, www.amazon.com/shops/miboxer , to get to the storefront, and the charger’s right there up-top.

I got my almighty battery charger yesterday, and am playing with it now… quite nice!

I was afraid of it charging up a 14500 LiFePO4 cell at 800mA, but I did find how to step it down to 100mA without even looking at the pamphlet. :smiley:

Thanks again!

Dido … very nice charger … bargain … :slight_smile:

HKJ our resident charger tester and expert didn’t have a lot of good things to say about it but did say it was “acceptable”. He said with some cells if you don’t take them out when the charging cycle is complete, it will continue to charge and could damage the cell.

Anyway, with leomilboxer’s discount and a discount coupon I had for Amazon, for a total cost of $4.00, I couldn’t pass it up! :slight_smile:

Found the review on lygte, still looks good.

I don’t leave cells unattended, at least not too long, so for me that’s not an issue. In fact, unless proven otherwise, I assume they do exactly that anyway.

Cell gets topped off, current stops, cell “rests”, voltage drops, charger tops off again. Rinse, repeat.

It’s still an almighty charger.

That was the first version of the C4. The versions that now sell on Amazon don’t have the termination problem. I think Leo sent HKJ the newer version as well. I got one from Leo, and it terminates fine. HKJ needs to update that review.

Did you buy the C4 or C4-12?

I thought the C4-12 does not have support for LiFePO4 cells?

The regular one. LFP support is kinda important to me now. Just did a cap test on a “600mAH” cell, which tested at 490mAH. Testing a second cell now…

If anything, I don’t need 3A support. I’d rather slow-charge cells anyway. My Ope can do 2A if I would.

Oh yeh, dinno if the code also worked for the –12.

That’s funny! At first I didn’t get it but when I received the charger, there it was, right on the front of the box. I wonder if it’s also a “holy” charger? :slight_smile:

Okay, here comes the dumb question. The instructions state that the charger automatically senses whatever cell you insert into it and adjusts the charge current accordingly to the cell’s size or chemistry.

Why then does it have adjustments for cell capacity and charging current? Just asking.

So that you can override it when it makes a dumb decision, which it will do on occasion. I put a 700mAh LiFePO4 in mine and it decided to start charging it at 800mAh. It might have stepped down by itself shortly but I didn’t want to take a chance on harming the battery, so I forced it down to 300mAh.

It also allows you to increase the charge rate (within reason) it you’re in a hurry and and are willing to possibly accept a slight decrease in battery longevity. I normally don’t like to see a Li-Ion charger go above .5C, but will push some to 1C if I’m in a hurry and they can handle it.

That’s pretty much exactly what happened to me.

LFP (“600mAH”, tested at a paltry 480-490mAH) started charging at 800mA. Sez me, “That can’t be good…”, so knocked it down to 100mA (no rush). That’d be charging at almost 2C if I left it.

Yeah, might’ve adjusted itself after a while, but wasn’t going to chance it.

Can the C4/C4-12 charge 21700 cells?

Looks like the adjustments are mainly for LFP cells which I don’t have any.

I prefer to slow charge my cells but I guess it’s nice to be able to fast charge them if desired.

I charged some old, original eneloop AA cells that weren’t holding their charges very well and wouldn’t charge up to full capacity with other chargers. This one charged them up to full capacity but we’ll see how they hold their charge.

If the 21700 is really 70 mm long, yes. My C4 can handle cells up to 70.5 mm long. My C4-12 however can take cells up to 73mm long.

(Edited 2/22/18, took actual measurements by stacking magnets on batteries rather than using a ruler, C4 lost 0.5mm length capacity)

Being able to adjust the new 2nd generation C4 can be a double-edged sword.

My old 1st gen C4 always charges all the batteries in a “set” at the same rate, so they all finish at pretty much the same time. With only two charge rate choices (350mA or 800ma), it doesn’t have any trouble picking the appropriate one from that short list.

However, since my new 2nd gen C4s can pick charge rates from 100 to 800mA (apparently in 50mA increments) its chosen rates may differ by 100mA or more among the four batteries in a “perfectly” matched/equally discharged set.

For example, earlier today I charged four Eneloop Xs and the automatically selected rates varied from 600 to 750 mA, so there probably would have been more than the usually expected difference in finish times. I forced all of them to a reasonable and leisurely 700 mA, and don’t really consider this worth worrying about, just an observation.

Slow charging shouldn’t be a problem with Li-Ions, BUT charging AA NiMH batteries at much less than ~300 mA can make the Delta V termination point awfully hard for some chargers to detect, which can result in cooked batteries. I haven’t tested it on this one and don’t plan to, because I’m not HKJ! This charger looks like it will allow some inappropriate rates to be forced, one just has to know enough not to go there.

I am having a similar issue with a C2-6000 charging new protected 18650 ga&bs. Picks a very low rate for some reason and does not boost it much .

Any plans for a coupon for the C4-12 charger Leo?