MiBoxer C2-4000 Smart Charger Review

Hey folks today we will be reviewing the MiBoxer C2-4000 battery charger. The C2-4000 was sent to me by MiBoxer for review I will leave a link to there amazon store here. None affiliate link!
Miboxer sent me 3 chargers at the same time so its a bit of rush to get them all done.
Also one more disclaimer I am no charger expert but I do own around 10+ so I have seen many different kinds of chargers.
The C2-4000 is the sister charger to the MiBoxer C2-3000 which I reviewed earlier in the year. Think of this as an upgraded C2-3000 features wise. Keep in mind that edition of the C2-3000 was the first one per-release so no manual control selection.
What is included in the box?

• MiBoxer C2-4000 charger

• Instruction manual

• AC Adapter multi voltage 100-240v

Design
Design wise the C2-4000 looks fairly different to the C2-3000 it is a bit beefier and chunkier and has lots more curves? How important is that? Well these curves are in all the right places like dips on the side wall of the battery compartment making it easier to place and remove your cells. The screen on both the C2-3000/4000 are the same size and they are both very well lite and easy to read. The C2-4000 like the C2-3000 has easy to read digits which is important to me the digital are of adequate size.
Build quality
Build quality is what you would expect from MiBoxer the C2-4000 is built great and is very well finished. It looks a tad more premium compared to my Liitokala engineer 500. The slide rails work well and the contact point are set up well to handle larger and smaller cells. The spacing in the bays is awesome and works well with any size cell you throw at it.
UI
The UI is okay the C2-4000 only has 2 buttons so not many option of keys to push. Changing current is easy to do and cycling between the different function and outputs like Ohm reading is easy. I did find it hard to navigate to the cell capacity testing it took more then a few tries of reading thru the manual to get it. I am not the best at finding obscure settings lol. Now i have done a few times it is much easier you only push 2 buttons and its on!
On the screen you will find a few different functions.

• Battery percentage for the first channel/bay

• First channel/bay

• Battery type

• Second channel/bay

• Battery percentage for the second channel/bay

• Remaining time/Charge time/ total charge and discharge time

• MAH (battery capacity)

• Charge/ discharge symbol

• Internal resistance/Current/Voltage

Features

• Compatible with batteries of Li-on (4.2/ 4.35v) lifePO4 (3.6v), Ni-MH/Ni-Cd 1.48v (All standard sized cells)

• Charges all types of cylindrical batteries Li-on and Ni-MH (10340-26650)

• Maximum charge current of 1.5amps per channel (3amp total max charge current)

• Manually set up charge and discharge current at your own discrepancy (Great for smaller cells like 10440 charge current can be set at 100 milliamps) (large cells current can be set at 1.5amps)

• High precision calibration source

• Reverse polarity protection and short circuit protection built in

• Intelligent temperature control function (Has an inbuilt fan for use with the discharge Mah test cycle)

• Automatically detects the battery and displays the state of charge

• Automatically measures battery internal resistance

• Measure the battery capacity during charge cycle

• Can measure actual capacity of a battery through charge-discharge-charge cycle

• Two fully independent slots (Can charge different range of cells at the same time)

• Supports small capacity battery charging (Min charge rate of 100 milliamps)

• Supports Li-on battery repair function (For cells with safety functions)

• Supports DC12v input (Able to use in the car)

• Made of PC fire retardant material

• Excellent heat dissipation and circuit design

• 3 year warranty

Performance
The MiBoxer C2-4000 is awesome performance wise. The C2-4000 can charge almost any cells you can throw at it. With the manual select letting you choose a wide variety of current options. The options are endless I will specify the current outputs below.
Current outputs

• 100ma

• 200ma

• 300ma

• 500ma

• 800ma

• 1000ma

• 1500ma

The MiBoxer C2-4000 utilizes the correct charging current for cells of all sorts. The C2-4000 uses Constant current and constant voltage CC/CV for all Li-on cells. This is the correct way to charge lithium cells and is much safer than pulse charging in some circumstances like charging smaller cells.
The C2-4000 does use pulse charging for Ni-MH which is the correct way to charge Ni-MH this way of charging is best to fully utilize a Ni-MH.
Cells types

• Li-on (4.2/4.35v)

• lifePO4 (3.6v)

• Ni-MH/Ni-Cd 1.48v

The MiBoxer C2-4000 charges and ends the cells cycle well from what I can tell. It stopped all my tested cells at the correct 4.20v and it did slowly lower the charging current as the cycles ends.
The Ohms read out on the C2-4000 are as good as any other battery charger it works okay. They should be used for general guidance and be all.
I will leave some tested Ohms here

• LG HG2: 60 milliohms

• Samsung 25r: 35 milliohms

• Sony VTC5: 43 milliohms

• Liitokala 26650: 35 milliohms

Capacity tester
The capacity tester works well and is fairly accurate it charges then discharges then charges a final time to find out overall capacity. It does save the data at the end of cycle in case you are not at the charger to read it. You should never leave lithium batteries alone while charging. The fan does only activate while in discharge mode to keep the charger cool I discharged 2 cells at 1.5amp each and the charger read 44 degrees Celsius. Discharge cuts of at 3v from what I can tell. After this 3v mark there is hardly no capacity left in a Li-on cell.
Tested capacity

• Samsung 25r: 2726ma

• Imalent 18650 (2600mah rated): 2554ma

Auto charging
Auto charging works good it charges according to the resistance of the cell in the slot. Generally a smaller cell will have higher resistance I am not sure how that works. Charged my Samsung 25r and they charged at 1.5amps which is fine for a high drain 18650 they read at @35 milliohms.
I tried my Soshine 10440 a fairly hard cell to charge because of its size many chargers are not suited to charging such low current. Auto charge selected 300ma charging current which is okay but still a tad high I would rather charge at 150-200ma. I have charged these cells many times at 300ma because my Liitokala engineer 500 smallest charge select is 300ma.
These Soshine 10440 read at 200 milliohms I would expect the resistance to be even higher then the reading. The major flaw in this auto charge is the fact that it uses resistance to select charge current. If you insert any protected 18650 it will charge fairly slow by default because the protection circuit adds extra resistance. This is why manual select is the way to go once you chose a current on manual mode the charger will stick to that current and not change unless you input a new charge current.
Last but not least I tested the C2-4000 with a Trustfire 14500 IMR cell its rated at about 600mah. The auto charged selected 450mah and gave me an Ohms reading of 155 Ohms. This charge current is acceptable.
Generally speaking you charge cells at half or less of there capacity. 300Mah cell go for 150mah or less charge current those Soshines have a max charge rate of 350mah. If charging 3 Amp 18650 go for 1.5 amps or less generally 1amp unless you are fast charging. Slower charging and or lower current may help with the longevity of the cell. This is also dependent on the batteries chemistry.
The MiBoxer C2-4000 is a great all around charger and incorporates some really useful features in a small and compact design. Although its only a 2 bay charger with the 1.5amp fast charge it can make up for the lesser overall slots by charger each cell faster.

Great review. I just ordered one. If I want to charge lifep04, should I select the voltage first then put the battery in or put the battery in, let the charge detect the type of battery then change the voltage?