eBay adjustable CC/CV module for 4.3v cell charging?

I recently got a giant pile of 4.3v Samsung cells (here), and don't have a charger capable of going over 4.2v. I know the capacity doesn't change a lot between 4.2 & 4.3v but I'd like to be able to use it anyway.

I have one of these CC/CV regulators and it claims to be able to do LiIon charging.

I've used it as a simple voltage/current regulator for fans and LEDs but not tried using it as a charger yet, because I'm not entirely clear on how to adjust it for charging a LiIon cell and would rather not try to figure it out through blind experimentation lest I guess wrong and have something explode.

Of the 3 pots one is voltage, one is current, and the other controls something to do with using it as a charger, though I'm not exactly sure what. I'm assuming it sets a cutoff point or something. Can anyone translate the description in the eBay listing into plain English and/or describe a test setup to check that it's doing everything correctly and safely while charging a cell?

I found a listing for the same board from another seller with a slightly more clear description, and a nice labeled photo:


Battery use:

Make sure of the voltage and current of the battery you need to charge
Adjust the constant voltage potentiometer to make the output voltage same to the charge voltage
Potentiometer Adjustment Direction: Clockwise (increase), counterclockwise (decrease)
Use the multimeter in 10A current scale to measure output short-circuit current, and adjust the current potentiometer to make sure the output current to the expected charging current value
The charge current of transfer lamp is default 0.1 times of the charging current (constant current value)
Connected to the battery and try to charging (for previous 5 steps, module input terminal is connected to power source, output load is NOT connected to batteries)

I've just confirmed my suspicions, and this is why I want to use them at 4.3v instead of 4.2v. I don't much care about the extra capacity between the two, but rather the performance.

P60, direct drive XML2 T6 3C on copper:

4.19v resting = 3.48A

4.29v resting = 3.94A

Charging manually works fine (using a plain CC/CV board without the special charging features). Cells are charged up to 4.20v in the hobby charger, then moved over to the other setup with the voltage limited to 4.32v and current limited to .95A (even doing 4 at a time and starting from 4.20v the current is self-limited to around 600mA and falls as the voltage rises), and I monitor the voltage. After it's been at 4.31v for a while I switch it off and check the resting voltage, cells are removed when they are steady at 4.30v after 20-30 seconds. Seems to be exactly the same thing a real battery charger does, I guess.

I don't want you to feel alone in this thread, so I thought I'd post something :) . I'm subscribing as I'm interested in this module for this use. Also a link to my thread on the possibility of modding a 4.2v charger to a 4.30v or 4.35v charger either through modding/adjusting or through replacing the inards with this module.


I don't know what happened to it, but the one in the first post died on me since the last time I used it. No voltage output.

I'm using one of these for now: http://www.ebay.com/itm/181089350031

The way I understand it, the board seem to favor CV but will not allow current to exceed the preset current. If so, this is exactly the way normal CC/CV li-ion charger works.

Set CV first to 4.3V (or 4.35V), the short the output with an ammeter to view and set max current (e.g 1A).

Coupled with a cheap $3 charger host, we’ve got a $8 regulated 4.35V 1A CC/CV charger. And even ready for future upgrades. Pretty good I think!

Ok, so who's going to try and test it? What charger "host" is big enough?


Set manually to exactly 4.30v it takes FOREVER to finish because the current automatically falls as well (but, they could be left charging essentially forever, no cutoff needed, just a manually adjustable voltage). The closer the cell voltage gets to the set point, current falls until it's zero.

I have mine set to 4.32v, after it's risen to that point it takes a while for the resting voltage to be a true 4.29-4.30v after the power's shut off. The 4 I'm charging right now just hit 4.32v, but immediately after cutting power the cells fall to 4.28v, so they still have just a little bit left to go. I take them out when they stabilize at 4.29v.

I just bought one off ebay for $3.11, but seems it’s not the same price elsewhere. Gonna be at least a month for me.

I don’t think this board fits the housing of a regular cheap charger. But I’m thinking to simply screw the circuit externally on a dryboard together with the battery host, or something similar like that.

So is there anything to do to speed it up or is it just the nature of this module and we need to find another module?


Yeah, set open circuit voltage to 4.32-4.33v. You have to remove power occasionally after it hits the set point and see where the cells are, though. I think one of the modules with built-in volt/amp meters might be better than the 3-pot boards, I'd rather monitor it myself than depend on something so cheap to shut off without blowing something up.

Here's another version of the 3-pot board, this one capable of 5A: http://www.ebay.com/itm/370884975034

You know, I don't think the third pot does anything but adjust the point where the charge indicator LED changes color, I don't think it shuts off. Depending on the set voltage that may not be anything to worry about.

nice setup

What did you use to attach the heatsink? just thermal grease since the screws are holding it?

Nah, there's 2 small screws through the AL into the plastic frame of the box, the lower screw through the regulator also passes through into the plastic, the upper screw is threaded into the aluminum plate. I've charged 4 flat cells at 4A and it didn't get even detectably warm, it doesn't need a heatsink but it was what jumped out of the junk box into my hand, so I used it. :party:

I have the same board. But the directions are still confusing to me. I wish someone would make a video on how to charge li-ions or maybe even LiFePO4s

Oh hehe, I saw metal and immediately thought heatsink.

Worrisome that the first unit failed as it looks like half of the unit I’m toying around with. :frowning:


I managed to resurrect mine - turns out, the through holes are not vias, the pads on top and bottom are not connected! I had the wires soldered over the top of the holes, all but the out+ had solder filling the holes and making the connection to the bottom layer. Resoldered everything and it works again.

OK, I think I have it figured out. The middle pot does nothing but set the point (based on current) when the 'charge' LED turns off and lights the 'OK' LED. The board does not shut off when finished, but when the cell voltage is equal to the regulator output voltage, no current will flow.

Set the open circuit voltage to 4.20v, 4.30v, 4.35v, whatever.

Short the outputs with an ammeter, adjust the current pot to the desired 'end current', or the amperage where you want the LEDs to indicate charge complete - say .1A. Then adjust the middle pot until the middle 'CH' LED just turns off. During the charge when current to the cell falls below that point the LEDs will change.

Short outputs again with the ammeter, set the max charge current, say 1A.

At the start of a charge cycle with a flat cell, current will be limited to 1A (the cell would take more than that, if it weren't limited). The far right LED (marked 'CC/CV') will be on, and the middle 'CH' led will be on. The 'OK' LED will be off. In this pic the 'CC/CV' LED is red and on dimly, the blue 'CH' LED overwhelms the camera:

In the middle part of the charge the current into the cell will fall under the 1A limit, the 'CC/CV' LED will turn off, middle 'CH' LED stays on.

Near the very end both 'CH' and 'OK' will be lit together:

When the charge current falls below the set point and cell voltage has risen to the voltage set point, the 'CH' LED will turn off, with only the 'OK' LED on:

The cell isn't completely finished at that point, but, since output voltage can never go over your setting, if you set it to the correct voltage it should be ok to let it run like that basically forever, I suppose. For a 4.30v setting if you remove the cell as soon as the 'CH' light turns off, cell's resting voltage will be around 4.26-4.27v. Another 15-20 minutes will bring it up to 4.29-4.30v.

Thanks comfy! I'm really tempted to try and adapt this module into a cheap charger, but I know it would be forever before I'd get around to it with so many mods sitting and waiting.


My idea would only work for a single bay charger, right? What would happen if you charged two in parallel but the batteries had different voltages? Would it still work for that?


If you put two batteries in a parallel box current will flow from the higher voltage one to the lower, whether you are charging them or not.

This board would do multiples in parallel, just crank up the amperage. But they all have to be fairly close to the same voltage at the start. I always charge LiIons in parallel or as singles, I don't have the patience to sort through everything needed to mess with balance leads and adapters and whatnot to do series charging.