Fenix Outfitters        
Page 1 of 2 12 LastLast
Results 1 to 30 of 59

Thread: Test/review of Miboxer C4-12

  1. #1
    *Flashaholic* HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    9,512

    Default Test/review of Miboxer C4-12

    Miboxer C4-12





    Miboxer is a new brand in chargers, this model is a four slot universal charger with automatic current selection.





    I got the charger in a cardboard box



    The pack included the charger, a power supply, a mains cable and a instruction sheet.



    The charger requires 12V 5A power and has a usb power bank output.



    The user interface is a single button and a large display.
    A short press on the button will switch between slots.
    A long press on the button will allow adjustment of charge current for the selected channel (with short presses).
    The interface is easy to use, but it is a lot of presses to select current for all slots.



    During power on all segments are shown.



    Charger is idle.
    The background light will turn off after a short time, the first button press will turn it on again.




    During charge the display will show voltage, charge current and internal resistance.



    WHen using usb output the usb current is shown on the display.



    The charger has the usual slider construction. It can handle from 31mm to 73mm, this means even the longest cells. The large plus connection also means it can handle D and 32xxx cells.












    Measurements charger


    • Power consumption when idle is 0.26 watt (Background light off).
    • Without power it will discharge a LiIon battery with 1-3mA depending on voltage.
    • Without power it will discharge a NiMH battery with about 0.2mA
    • A full LiIon battery will be pulsed with a few mA.
    • At 0V battery voltage the charger will charge with 1.5mA.
    • Above 2V the charger assumes LiIon
    • The charger will restart when a battery is inserted or power is cycled.
    • The meter is within 0.01V and works from 0.02V


    Charging LiIon

    Charging current: Auto, 0.1A, 0.2A, 0.3A, 0.5A, 0.8A, 1A, 1.5A, 2A, 2.5A, 3A



    A nice CC/CV charge curve with termination around 60mA. The tick on the curve is a internal resistance check.



    Display shows: 3181mAh, 173mohm, 4:40



    Display shows: 3095mAh, 77mohm, 3:57



    The other channels looks similar.
    Display shows: 3054mAh, 111ohm, 4:22



    With the charger on auto it will select current depending on the internal resistance of the battery (And my measurement resistor). After about 10 minutes it do a IR check and increase the current slightly.



    This time it increase the charge current to 1.6A after a IR check.



    Again a nice charge curve.



    A slightly large cell that can easily hand a 3A charge current, the charger do a nice job.



    This very old and worn down cell is also handled nicely, with a very low charge current.



    With the automatic selection the charger is a bit slow to charge this cell, but it do get charged nicely.
    Display shows: 727mAh, 322ohm, 3:57



    The charger can charge 4 cells at 3A, but these cells is heated significantly.



    Charging four cells at 3A requires nearly 5A from 12V. For the first test I used a 4A power supply, the charger handled that very nicely by reducing the charge current a bit.



    M1: 46,1C, M2: 47,4C, M3: 49,5C, M4: 47,3C, M5: 46,5C, HS1: 63,4C
    Charging 18650 at 3A means the batteries will generate some heat.



    M1: 42,4C, HS1: 50,5C



    The charger uses a internal resistance check to decide the charge current and will then ramp the charge current slowly up.



    It is possible to overide the current setting at any time.




    Measuring Internal Resistance LiIon



    The results looks good and the consistency is also fine.



    Charging NiMH

    Charging current: Auto, 0.1A, 0.2A, 0.3A, 0.4A, 0.5A, 0.6A, 0.7A, 0.8A, 0.9A, 1A



    This is a nice -dv/dt termination with no top-off or trickle current.





    Display shows: 1641mAh, 69ohm, 1:58



    The 3 other also shows the nice -dv/dt curve.
    Display shows: 1639mAh, 153ohm, 1:58



    I uses auto mode for this cell, the charge current was a bit low, but the charge looks fine.
    Display shows: 2252mAh, 89ohm, 5:42



    A problem with using low charge current is a missing -dv/dt signal, but the charger terminates fine on this cell (I do not know if it is due to timeout or because it detects a full battery).
    Display shows: 2814mAh, 171ohm, 15h



    Display shows: 1686mAh, 97ohm, 5:30



    I selected a very low charge current for this cell, the charger did not like it and reported error after some time.



    The AA is handled nicely.
    Display shows: 637mAh, 104ohm, 2:14



    With -dv/dt it takes some time to detect a full cell.
    Display shows: 54mAh, 224ohm, 0:12



    No problem with 4 cells.



    The charger uses about 1.5A from 12V to charge 4 cells.



    M1: 34,4C, M2: 33,9C, M3: 35,5C, M4: 33,7C, HS1: 46,5C



    The charger starts up with low charge current and after some time change to high charge current. This makes it possible to select low current before the charger switches to high current.
    The total staring time is about 25 seconds.





    Current can be changed at any time. As is common with all NiMH chargers the current is turned off to measure the NiMH voltage.



    Measuring Internal Resistance NiMH



    I have a bit problems with contact resistance here, especially on slot #3, but the final result looks fairly good.



    USB output (Power bank)

    • Without power it will discharge a LiIon battery with 1-3mA depending on voltage.
    • Usb output is coded as DCP
    • Usb output uses slot #4 for power.
    • Usb output will turn off after 30 seconds with below 75mA load.
    • Usb output turns off when power is connected to the charger.
    • To keep display and usb power on requires about 42mA from the battery (17mA when background light is off).





    With a full battery the usb output can deliver exactly 1A, before the output voltage drops. Overload protection kicks in at 1.5A



    The output voltage stays nicely at about 5.2V when I draw 0.5A



    With 1A output the boost converter has problems maintaining the output voltage, this is not very impressive.



    At 0.5A the noise is 106mV rms and 1244mVpp



    At 1A the noise is 159mV rms and 1615mVpp, this is way to much noise.



    The current display is not precise at low currents.

    Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.



    Conclusion

    This charger can handle four 26650 LiIon cells at 3A, this is a very impressive charge current. It can either do automatic current selection based on internal resistance or current can be selected manually. For optimal charge speed manual selection must be used, automatic will use a high current for new cells and a low current for old cells.
    The internal resistance measurement circuit works fairly well, especially on LiIon.
    I wonder why the charger has a power bank function, the charger is too big to carry around and with only one cell feeding the power bank it cannot deliver that much output power. In fact it is a fairly weak power bank with a lot of noise.

    I will give the charger a good rating.



    Notes

    The charger was supplied by Miboxer for review.

    Here is an explanation on how I did the above charge curves: How do I test a charger
    My website with battery, charger, usb reviews, comparisons & information: https://lygte-info.dk/
    Latest addition is multimeter reviews

  2. #2
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    Thanks for the review HKJ, i have one on the way from my battery guy Norb. He recommended me this over the Dragon as he said he is not over impressed with it. When i spoke with him, he mentioned about quite a few returns with blank display on a bay or not working etc(sold over 40 of them). So this was his suggestion, should have tomorrow so will try out over the weekend. The (up to) 3a per bay will be useful when i am charging 4 cells together, as the opus limits to 1a(still going strong the bt c3100 v2.2). Will have to see how i get on with the UI and being a single button. I was kind of hoping it would show the voltage of all bays together, as i am use to that and find very useful. Not a deal breaker though............

    Iirc, the miboxer is made at the same place xtar(and others use), but of course to their specs. He seems impressed with the build and reliability so far anyway.

    Cheers

  3. #3
    *Flashaholic* HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    9,512

    Default Re: Test/review of Miboxer C4-12

    Please report back what you experience with it is. It is always useful to get practical experience, my test with a couple of batteries will not reveal everything.
    My website with battery, charger, usb reviews, comparisons & information: https://lygte-info.dk/
    Latest addition is multimeter reviews

  4. #4
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    I will do HKJ, should not take too long as i will be using it instead of the opus for a while. So it will be used pretty much most of the time i am awake! Thanks again for everything you do, its really appreciated

  5. #5
    Flashaholic pc_light's Avatar
    Join Date
    Feb 2004
    Location
    Garden State, USA
    Posts
    456

    Default Re: Test/review of Miboxer C4-12

    HKJ, awesome review as always.

    FWIW to those who use LiFePO4 cells, I don't know about the other MiBoxer models but I have the C2-4000 and it has a LiFePO4 mode.

    I've retired my NC-D4 since getting the MiBoxer, being able to refresh batteries, getting a handle on internal resistance, and total capacity allows me to whittle out exhausted cells.
    "may you live light and phosphor" - Mr. Spark

  6. #6
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    The c4 -12 does not support LifeP04 cells afaik, also no 4.35v support. The latter would have been a bonus for me, make my life a little easier. But as i have a charger(vpII) upstairs and the opus bt c3100 next to the C4, i can still top my sany 16650 cells off to 4.35v if needed.

    C4 today off Norb at ecoluxshop, initial impressions are good, solid nice plastic of xtar type quality. Anyone with a vp4 etc etc will know what i mean................nicely made! .

    Wrapped in bubble wrap for extra security


    What also stands out is the decent quality power pack 12v 5a

    Quick size comparison with some well know chargers


    Next to the opus,


    Nice clear display(yes i know ,i have now removed the screen cover lol)

    Like how the display changes from V to IR every few seconds


    Too early to to know much on the auto select, but the press/hold of the button and then short press to go through charge levels works well. No waiting too long for it to allow changes.............like it. Also like the charge options from 0.1a/0.2/0.3/0.5/0.8/1/1.5/2/2.5 / 3a . So pretty much enough (or little) to cover all li ion cells. I just chucked in a vc4, it picked 1.55a.............so there must be some little extra levels in between the pre-set ones.

    Early days(hours) , but so far it seems a very good charger. I will have to check with my MM to see how close it is in V and to make sure it terminates(always do a few safety checks).

    Oh and one last thing(for now), the bay sliders are some of the smoothest i have had, No extra bit of lube required.

  7. #7
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    3.67 and 3.66v my fluke measured on the ampsplus 18350's(aspire inside). When placed in the c4-12, the display read the same as the meter. These i need to measure when they terminate and settle.

    Now my vtc6 ampsplus i have measured after termination, both showed 4.2v on the C4, the fluke measured 4.18v. So it seems accurate for the initial voltage reading when placing cell/s in charger, but potentially a 0.02v difference on the termination V..............not sure how that can happen.

    18350, show 4.2 full

    MM measurement


    So 0.01v difference there, not enough to be an issue for me. I know simply that the cell coming off the charger will be 0.01-0.02v lower than C4 display..............not perfect but good enough .

    The ampsplus(aspire) are to feed this beast , to take over from the 8a KeepPowers
    Last edited by ven; 02-09-2018 at 11:25 AM.

  8. #8
    Flashaholic*
    Join Date
    Mar 2013
    Location
    Southern Ontario
    Posts
    946

    Default Re: Test/review of Miboxer C4-12

    I received one of these a couple months ago from miboxer for review but I never did it as it was faulty and I never heard back from them about the problems which there are two. On slot one it will not terminate charge on a NiMH cell. Will only say 99% and stay there while still delivering current which is a real problem. The second fault is on slot #3 where it will show an error when inserting either a NiMH or a lithium cell and it will not charge. So for me this charger is a fail. I can only charge 3 lithium or 2 NiMH at a time and with only the 4th slot giving output it doesn't seem like a good product to me. Also I feel 3A is too much and not needed for any cell to charge at except a big NiMH. Which only goes to 1A. And I could not get connection on D size cells either

  9. #9
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    Bummer vicv, sounds like a duff unit. I will see long term how this holds up, so far so good. I have tested all bays now, also nimh which terminated at 1.49v. I have been testing the auto current select(just putting cell in the bays and letting it choose the current). So far its been spot on, so hoping it will be a case of just sit the cell in without even pressing a button!

    My 20700 cells at 3.7v , got a 2.3a current, my pany B(old cell) at 4.1v got 0.45a to top off. Another vtc4 cell at 3.7v got 1.55a. Both my AA nimh got 1a selected by the C4. So pretty happy with it..........

    Yes 3a is pretty high, but many high drains can handle it if you need a fast charge. Not something i need on each bay, but still nice to have if i need them charged quick. My high drain 26650 cells for example will like the 3a setting. But 2a on all 4 bays is super useful for my high drain 18650 cells(or even 1.5a x4). I kind of got fed up a few times when charging 4 cells at 1a on the opus.........

    The temp reading for each cell is pretty useful to, so far anyway it seems a nice upgrade from the opus(which will still be in use along side the C4).

  10. #10
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    I had a quick look on eBay and non of the C4 models listed have the external charger (brick) nor specifies C4-12 just C4.

    Are there more than one of these?

  11. #11
    Flashaholic*
    Join Date
    Mar 2013
    Location
    Southern Ontario
    Posts
    946

    Default Re: Test/review of Miboxer C4-12

    Yes the C4 is the original charger they made. I did a review of it

  12. #12
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    Ok, this one is not listed at the two places I just checked. I wanted to see what it would cost me here. Amazon Canada doesn't have either ones listed.

    I'll look again in the spring it may be too new.

  13. #13
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    Amazon.com and gearbest have the C4-12, not sure on delivery to Ontario though.

  14. #14
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    Thanks, Gearbest will ship. $61 for it.

  15. #15
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    I like the fact that it come with a high end brick charge and not a cube barely able to provide the required current when the 4 slots of others are being driven to the highest setting as in LiION cells. Also the longer slots for buttoned protected cells. From my recollection this seem much better than the V2.2 Opus.

    I don't know why it only got a GOOD rating. All be it the USB and Power bank were less than stellar. But I and many don't care.
    Who buys a charger wanting USB charging station as well. I have no less than 8 place to charge USB phones if I counted and would take up no space. Most are >1A as well.

    From my view reading the repeated reports of the charging being good as well as the cut off of all the cell. I would have expect a tad better than a mere good. Even the voltage accuracy and measurements are bang on for our purposes. Any variation at 1/100th of a volt is meaningless. I believe someone pointing out they saw it .02 less than displayed like it was bad and if it were .02 greater than displayed it would be the end of the world. LOL

    I have read enough reviews where there are a number off factors off by enough to be concerned for charging purposes. This did not have any by the end of the charge tests for both platforms of LiION and NiMH.

    I would say its a very good charger based on what I read. People who have bought them please provide your real world opinions. I don't have the luxury of buy load of chargers out of curiousity since they're all imported for me (returns are no viable) and cost on retirees budget being a factor. I want to pick the right product to fulfill my needs and a bit more.

  16. #16
    *Flashaholic* HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    9,512

    Default Re: Test/review of Miboxer C4-12

    Quote Originally Posted by tripplec View Post
    I don't know why it only got a GOOD rating.
    A good rating means it does everything about right, with the charge current selection based on internal resistance in the batteries it is impossible to get a better rating, because it will use too high current for new batteries and a low current for old batteries.
    My website with battery, charger, usb reviews, comparisons & information: https://lygte-info.dk/
    Latest addition is multimeter reviews

  17. #17
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    I did not notice it going too high in your graphs but quite the opposite as it seeks a sweat point. i did see you mention for faster charging manual charge setting was require. Eg for 2A if desired.

    The auto mode had the steps ramping up to an acceptable rate for most of us.

    Thanks for the clarification anyway.

  18. #18
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    Been using none stop now for 4 days, granted not long but very happy with it. I was very happy with the opus back a couple of years, same kind of happy. Does what it says on the tin, terminates as should, quick charges the cells and drops the rate as close to termination(as it should). So far now i have been mainly using the auto mode for convenience..................by that i mean put cell in bay! No button press/hold, just drop in and leave to top off.

    To nit pick, the display is quite large and clear, could be used better IMO. There is enough room/space to have all 4 cells showing the voltage/IR (even if it switches every 5 seconds). 1/3 of the display(upper) is lost to an empty cell shape with a flashing lightning bolt when charging............not required. Read out above each cell would be more useful and convenient than having to press button to move through the 4 bays to check each voltage.

    If i had to score it, it would be about 8/10. No 4.35v support and display could be improved for a 9!! Just hope it proves to be as reliable as the opus bt c3100, faultless for 2 years or so now, used daily, 7 days a week.

  19. #19
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    I started looking for one of these as it seem quite good and long slots for battery. One of the few. However, the images are quite different than the product reviewed. Name and plastic is not the same as in the review above. Has the charger been alter/upgrade to this?

    Oh wow, this board doesn't allow me to Upload a photo. How archaic...

    Well its show at this amazon listing. https://www.amazon.ca/MiBOXER-Batter...=miboxer+c4-12

  20. #20
    Flashaholic
    Join Date
    Jun 2013
    Location
    Belleville, Ontario
    Posts
    349

    Default Re: Test/review of Miboxer C4-12

    I searched for info and it appears this is C4V model 1.5A charger. I have not seen it review or mentioned before. Maybe its very new but being show/sold as a C4-12 as one recent deals post found on Amazon.com earlier this week.

    I guess we has to assume nothing from sales ads and double check and recheck being skeptical.

  21. #21
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    A update around 10 months (December) a spring snapped on one of the bays. Fixed this, then another went, then another. The springs are very thin where they bend through the slider. Fitting longer cells must have put a strain over time(20700). I contacted the seller, sent a few pics of said snapped springs and received a new charger. The actual slide design looks a little different on the new c4-12, but without opening it, looks to be similar type springs(was hoping to be beefed up a little).

    Only time will tell, offered to return charger but no need. So bought a spring kit off amazon and fitted beefier springs. Had to snip the ring end(one ring kept for the post, other opened up to feed through the slide neg pole.)

    More resistance now , so have to be careful not to take the posts out! Other than weak springs, this charger has been nothing short of excellent. Most cells right now being charged are 26650s, voltage around 3.4 when placed on charge(Vape mod). Rate varies a little, 1.5 to 2.5a. The vtc6 and other higher drains can be up to 3a. It does pick a low rate for 16340 cells, usually 0.15 or a little higher. Still its rare that a cell is on charge for much over an hour(not actually timed though). Of course you can manually over ride easy enough, press and hold and select rate. I have to do this with eneloop AA especially, as these get around 0.3a selected. Max is 1a for nimh, thats fine for me and thats what gets selected.

  22. #22
    Unenlightened
    Join Date
    Dec 2013
    Posts
    1

    Smile Re: Test/review of Miboxer C4-12

    Quote Originally Posted by ven View Post
    A update around 10 months (December) a spring snapped on one of the bays. Fixed this, then another went, then another. The springs are very thin where they bend through the slider. Fitting longer cells must have put a strain over time(20700). I contacted the seller, sent a few pics of said snapped springs and received a new charger. The actual slide design looks a little different on the new c4-12, but without opening it, looks to be similar type springs(was hoping to be beefed up a little).

    Only time will tell, offered to return charger but no need. So bought a spring kit off amazon and fitted beefier springs. Had to snip the ring end(one ring kept for the post, other opened up to feed through the slide neg pole.)

    More resistance now , so have to be careful not to take the posts out! Other than weak springs, this charger has been nothing short of excellent. Most cells right now being charged are 26650s, voltage around 3.4 when placed on charge(Vape mod). Rate varies a little, 1.5 to 2.5a. The vtc6 and other higher drains can be up to 3a. It does pick a low rate for 16340 cells, usually 0.15 or a little higher. Still its rare that a cell is on charge for much over an hour(not actually timed though). Of course you can manually over ride easy enough, press and hold and select rate. I have to do this with eneloop AA especially, as these get around 0.3a selected. Max is 1a for nimh, thats fine for me and thats what gets selected.
    Thanks for the update. I just purchased this charger for my Samsung 18650 Q30's - Got a SOFIRN Q8 this week for Search & Rescue work. I'd like to keep my sets of 4 cells binned properly. I think this charger will do it.

    A Very Big thanks to HKJ for the awesome technical review.

  23. #23
    Flashaholic* hiuintahs's Avatar
    Join Date
    Sep 2006
    Location
    Utah
    Posts
    1,840

    Default Re: Test/review of Miboxer C4-12

    Quote Originally Posted by tripplec View Post
    I had a quick look on eBay and non of the C4 models listed have the external charger (brick) nor specifies C4-12 just C4.

    Are there more than one of these?
    There are a couple of different models of Miboxer C4....... the original C4, C4-12 ($45.99), C4S, C4 Plus ($36.99), C4 Upgrade ($29.99)................just to give an idea on difference in price on Amazon. There are some differences between models. You have to compare pictures and description with Miboxer's website to make sure you are getting the one you think you are. I wish Miboxer would have a comparison chart to see the differences between models.

    I got the C4-Upgrade for its longer cell capability (21700). I think a couple of the other models will do that size too. The Upgrade unit also does 4.35V along with 4.20v and NimH. (I think some of the others may do that also), Only 1.5A per bay which was fine by me. No power bank feature which I was just fine with and two power sources.......12v or AC plug. I did not want a charger powered by USB when doing heavy loads. C4-Upgrade is less money than the 2.5A, C4 Plus or the 3A C4-12, but seems to do everything the Plus unit does. Also no discharge feature on this one. I may look at getting a C2-4000 in the future for that feature.

    Last edited by hiuintahs; 02-09-2019 at 02:12 AM.

  24. #24
    ven's Avatar
    Join Date
    Oct 2013
    Location
    Manchester UK
    Posts
    21,099

    Default Re: Test/review of Miboxer C4-12

    Pics, older charger on left, latest on right. Can see subtle differences with neg contact and also positive(only noticed this taking the pic)


    Breaks wise, the ring that secures around the post are fine, its the end that fits through the negative that gives.


    No post broke so far, just springs.

  25. #25

    Default Re: Test/review of Miboxer C4-12

    Quote Originally Posted by hiuintahs View Post
    There are a couple of different models of Miboxer C4....... the original C4, C4-12 ($45.99), C4S, C4 Plus ($36.99), C4 Upgrade ($29.99)................just to give an idea on difference in price on Amazon. There are some differences between models. You have to compare pictures and description with Miboxer's website to make sure you are getting the one you think you are. I wish Miboxer would have a comparison chart to see the differences between models.

    I got the C4-Upgrade for its longer cell capability (21700). I think a couple of the other models will do that size too. The Upgrade unit also does 4.35V along with 4.20v and NimH. (I think some of the others may do that also), Only 1.5A per bay which was fine by me. No power bank feature which I was just fine with and two power sources.......12v or AC plug. I did not want a charger powered by USB when doing heavy loads. C4-Upgrade is less money than the 2.5A, C4 Plus or the 3A C4-12, but seems to do everything the Plus unit does. Also no discharge feature on this one. I may look at getting a C2-4000 in the future for that feature.

    I just bought the c4 upgrade version and the lack of temperature sensorl worries me.
    It can do 1.5a which for nimh can be a problem.
    I had a AAA in that had probably just finished charging and the cell was super hot, I could barely touch it.

  26. #26
    Flashaholic* hiuintahs's Avatar
    Join Date
    Sep 2006
    Location
    Utah
    Posts
    1,840

    Default Re: Test/review of Miboxer C4-12

    Quote Originally Posted by hammerjoe View Post
    I just bought the c4 upgrade version and the lack of temperature sensorl worries me.
    It can do 1.5a which for nimh can be a problem.
    I had a AAA in that had probably just finished charging and the cell was super hot, I could barely touch it.
    Ya, I wouldn't charge an AAA at 1.5A..........probably just 500mA max. Usually I do around 250mA on the AAA's. Do you know what current you were charging the AAA at? If the charger missed the dv/dt termination point then all the charge energy turns to heat. I mostly got the charger for the different sized cells and voltages like 21700 and 4.35v. So really haven't used it much for NiMh. I've thought highly of the charger but I haven't used it a lot. I'll have to charge some AAA Nimh to see how mine behaves and report back.

  27. #27

    Default Re: Test/review of Miboxer C4-12

    Quote Originally Posted by hiuintahs View Post
    Ya, I wouldn't charge an AAA at 1.5A..........probably just 500mA max. Usually I do around 250mA on the AAA's. Do you know what current you were charging the AAA at? If the charger missed the dv/dt termination point then all the charge energy turns to heat. I mostly got the charger for the different sized cells and voltages like 21700 and 4.35v. So really haven't used it much for NiMh. I've thought highly of the charger but I haven't used it a lot. I'll have to charge some AAA Nimh to see how mine behaves and report back.

    I must have just missed the charging so I dont know what it was charging at. It was very hot.
    It was the only one that I noticed.

  28. #28
    Flashaholic* hiuintahs's Avatar
    Join Date
    Sep 2006
    Location
    Utah
    Posts
    1,840

    Default Re: Test/review of Miboxer C4-12

    OK, So I charged two different AAA's at different times in different bays. And everything went well. I just let the automatic mode work and did not adjust any settings after putting the cell in. This is what I noticed. It picks a charge rate based on the internal resistance that it measures. With the first cell, it set the charge rate at 0.30 amps. I did not look at it further to see if it went up or down any because I forgot about it. When I went to check on it, charging was done. Voltage was at 1.44v and battery was cold. With the 2nd cell, I also let the automatic feature work. It said the resistance was lower and thus it set the charging rate at 0.55 amps. I also forgot to check things and found the charge completed, battery voltage at 1.44v and battery cold.

    I think in the future, I'm going to set the charge current rather than rely on the automatic mode. That way I feel I have more control. I wonder if there was a possibility with your charger that the charger measured the internal resistance too low for some reason and thus put the charging current too high for an AAA. Hard to say unless you actually took note of some of those values on the screen after charging was in play. Thus what you might do is charge up different batteries in different slots and note how things are going as they progress towards fully charged. With the Eneloop NiMh batteries, I've noticed the dv/dt point to be around 1.50v. But it can vary +/-0.02v. So once the voltage gets close to that pay more attention to what is going on and perhaps periodically along the way noting charge current, voltage, time, internal resistance, & temperature via touching. What you want to find out is if you have a problem with your charger or battery, was it a one time anomaly, or a problem with a particular bay.

    I'd be curious to know what you find. Since we have the same charger if there are any specifics you'd like me to do on my end, let me know.
    Last edited by hiuintahs; 06-05-2019 at 09:30 PM.

  29. #29

    Default Re: Test/review of Miboxer C4-12

    It was only one cell that I found was super hot. All the others I put in are cool to the touch.

    This charger is very interesting. I wish it had temperature sensor to make sure theres no overheating. Perhaps in a future new version which will no doubt will be available or perhaps I should look at the original charger.

    Anway I like this charger and I especially like the automatic charging amperage based on the cell resistance.
    I think in the future when im looking for a new charger this will be an important feature I will look for.

  30. #30
    Flashaholic* hiuintahs's Avatar
    Join Date
    Sep 2006
    Location
    Utah
    Posts
    1,840

    Default Re: Test/review of Miboxer C4-12

    Which bay was the cell in? What you should do is mark that cell so you know which one it is and move it to another bay and charge there next time. Also I'd charge a different cell in the bay that is suspect. Could it possibly be related to the bay or maybe the cell was the problem?.............Just some thoughts.

    Miboxer has recently come out with the "Upgrade C4-12" which has temperature reading displayed. Now whether it uses that in the charging algorithm I'm not sure............but I think it does based on the literature. That charger also has two yellow buttons and has some changes from the original C4-12 that make it more to my liking. I have not seen it available on Amazon, U.S. yet. Rather than get a spare Upgrade C4, I think I might be interested in the "Upgrade C4-12 as a 2nd unit. Price will likely be around $40 on Amazon is my guess.
    http://www.miboxer.com/eng/p6u.html

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •