This charger is a very small module for DIY people, it uses the TP4056 controller and standard configuration is with 1A charge current. It does not include any power supply or tray. It did not include any documentation either, just a couple of boards.
The review is about a specific charger module, but any module with the TP4056 will have identical performance.
I got it in an envelope with 5 circuits on 2 boards and nothing else. The boards is precut and very easy to break apart.
There is some documentation on the sellers ebay page.
A close study showed that there was a small difference between the size of the boards.
The board needs a 5 volt power supply, this can either be from a mini usb connector or soldered directly to the board.
The "current resistor" can be replaced for other (lower) charge currents, because it is a 0603 size smd resistor (i.e. very small) it can be difficult to replace it.
On my boards I have a blue led for charging and a red led for done.
The charge led will be on when charging and it will be flashing when no battery is connected.
The done led will be on when charging is done or no battery is connected.
The backside of the board has some internal connections and the connections points are also accessible here.
The board is small, the battery is a AAA battery.
With the mounted resistor the charger can handle larger batteries, but changing the resistor makes it to possible to charge smaller batteries.
Measurements
Below 2.85 volt the charger will charge with about 80mA in 1A configuration (blue led is on).
Above 2.85 volt the charger is applying regular charge current (See curve below).
When charger is disconnected from power, but with a battery in, it will draw below 1uA from the battery.
When the charge current goes below the termination current the charging is stopped and it will charge with around 4 uA.
The charger will restart charging when the cell drops to 4.0 volt.
The charger will not restart after a power loss or battery insertion, except if the battery voltage is below 4.0 volt.
First test is with a 3400mAh battery, the charger does a good CC/CV, except the change from CC to CV is a bit soft, this increase charge time but has no bad effect on the battery. The charger is also a bit below the 1A current, it only charges with 0.85A.
The CV voltage is slightly below 4.2 volt, that is not surprising, because the datasheet for the TP4056 specify that it can be between 4.137 and 4.263 volt. This chip uses 1/10 of the charge current as termination current.
I added a temperature measurement to the test this time, as can be seen the chip heats up fast and then slowly drops in temperature when the battery voltage increases.
Reducing the supply voltage to 4.5 volt, increases the charge time and reduces the temperature, but the final voltage is slightly lower.
Increasing the voltage does increase the temperature, but also reduces the current. When the chip gets to hot, it reduces the current.
Here I have added a heatsink to keep the temperature down (Remember electric isolation between PCB and heatsink). It works very well, the temperature is lower than with 5.0 volt supply.
The heatsink was just a piece of aluminium under the board with some isolation between.
My old 16340 IMR cell is also charged without any problems.
Modified resistor
Replacing the standard 1.2 kohm resistor with a 2.157 kohm reduces the charge current to 470mA.
The resistor is a 0603 SMD resistor, i.e. it is 1.6 x 0.8 mm.
Here a 0603 resistor is placed next to an old style quarter watt resistor.
Again the charger does a CC/CV charging, because the charge current is lower, the termination current is also lower.
A 16340 battery is a more reasonable size to charge with 0.5A.
Replacing the standard 1.2 kohm resistor with a 4.726 kohm reduces the charge current to 210mA.
Again I tested with a16340 battery and get a CC/CV curve.
Conclusion
The charger has a good CC/CV profile and can be adapted for many different charge configurations, for multichannel operation it is easy to use multiple board, for smaller batteries the resistor can be replaced. When used at 1A it might be a good idea to mount it on a small heatsink (Remember isolation), to avoid any slowdown in charging and keep the temperature down.
I do not like that it is using a mini usb connector, a micro usb connector would have been better (That is the same as used on phones).
I will call it a good charger for DIY projects.
Notes
I bought the module on ebay from "1984yht888" where it is called "5pcs Mini 5V USB Interface 1A Charging Board Module Charger For Lithium Battery"
The temperature measurements is not the chip temperature and probably not even the surface temperature of the chip (I believe that the probe is affecting the measurement).
Thanks for the review! Now that I know they work well I will probably order a few more. :) Do you have any idea what will happen if you insert the battery backwards?
Good to know. :P Thanks for doing that though, I had considered using these as giveaway chargers(hooked up to a 1*18650 case) but now I won't. Did it do any damage to the battery? (short it out or anything like that)
I used a protected battery and when the charger start smoking (within a second) I disconnected everything again (Old habit). I did not even look at my meters to see if the protection was tripped. The protection is not tripped now, but I do not know if the protection does automatic reset on the used battery (intl-outdoor 3100).
I had checked the TP4056 datasheet first and it did not say anything about reverse battery protection, i.e. I was not very surprised when it went up in smoke.
Thank you HKJ for your test of this charger board.
I have been using my four charger boards very successfully , powered by my 5V 4A switch-mode PSU … I have set the PSU voltage to a few mV below 5V and am very happy with the performance … My PSU has four USB sockets attatched and I have 50cm interconnect cables (USB to mini-USB) … I personally have no problem in using mini-USB connectors … For me it was just a simple matter of buying the right 50cm cables which are now kept in a box along with the charger boards , the PSU and the magnets.
Will you be testing these boards in parallel to give a higher charge current ? … Some users might prefer a higher charge current when charging 3100mAh Li-Ions … On the other hand , two boards in parallel with each set to a lower charging current than one amp would also reduce the temperature of the chip … That would only increase the charger cost by another £1 or so.
Can you suggest a better method of attatching a heatsink to the module or indeed to the chip itself ? … … I did try cooling with a small fan , but although it did cool the chip it didn’t seem to reduce the charging time significantly … I understand that these chips will tolerate a fairly high temperature so perhaps just a simple heatsink would be the way to go … My boards are used in a near vertical position with the USB at the top , so maybe there is a slightly better cooling airflow.
Thanks again for your great charger board tests (including the destructive test !).
s. Does the Cottonpickers charger use the same chip ?
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For four charger boards it would be easier to just solder a cable between them.
Micro usb connectors are much stronger than mini usb connectors and with many phones using them also much more common.
I do not plan on testing any more on them.
As you can see on my curves, there is no reduction in current at 5 volt input, but electronic always last longer at lower temperature. The easiest heatsink is just a piece of aluminium, where you place the board against (Remember some isolation between), as you can see on the temperature curve, the temperature was reduced significantly.
At one time it was TP4054, I do not know if he is still using that chip.
What insulation material do you suggest to go between the back of the board and the alluminium heat sink ? … Presumeably it would have to transfer the heat through to the alluminium.
Would it be better to glue (somehow) a small (finned) heatsink directly to the top of the chip instead ? … This would not need any insulation material.
On the other hand , copper shims might glue on the back of the board OK.
Or maybe just leave the charger boards as they are , without heatsinks … I have not had any trouble so far … If they do get too hot , the chip will apparently automatically reduce the current as necessary … It’s only for the first part of the charge that the chip heats up anyway and mine were less than 65C at worst … Even holding my finger on the chip for a while reduced the temperature according to my infra-red thermometer.