External charger for mobile phone batteries

[sacentre]

Hi newbie here

I would like to build an external charger for my mobile phone batteries. My wife and I use Samsung Galaxy J4 and J7 Duo models both of which use the same Li-ion battery

Nominal voltage 3.85V = / 11.55 Wh
Charge Voltage 4.4V = / 3000mAh.

My J7 Duo came with a spare battery so it would be very convenient to have the means of charging one while using the other. Can anyone point me to a circuit or ready made module I could make or buy that would do the job without damaging or shortening the life? I would have just bought a charger but can't find anything suitable for this size and spec of battery.

TIA
Trevor

 

[Bluejets]

Lithium charger modules available from Ebay for around $3.00. Run on a wide range of input voltages and 3 pot adjustment facility for max voltage, max current and trip level( latter usually does not need adjustment)
How are you with basic electronics, have a multimeter???
Difficult part might be an adaptor to suit the battery.

 

[sacentre]

Thanks Bluejets
I see those but am confused as to which one would be the appropriate one. I am confident with an MM but better with mechanical stuff than with electronics. If it's not too much to ask, could you point me to the 3-pot one you have in mind.
Trevor

 

[Bluejets]

Only have my phone at the momentbut will send details a bit later.

 

[Bluejets]

First is the one I referred to....details are further down the Ebay page

https://www.ebay.com.au/itm/LM2596-DC-DC-Step-down-Adjustable-CC-CV-Power-Supply-Module-Converter-LED-Driver/123288297784?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

There is also one i remember I used to build a usb charger for a small portable scope.......might be easier for you to use.........actually probably better for you

https://www.ebay.com.au/itm/2PCS-5V...2406231161?epid=595263530&hash=item212812a479

As with the one above, there are some user details further down the Ebay page.
Usually find some useful info on youtube as well.

 

[sacentre]

Thank you Bluejets. Much obliged for the helpful info. I'll try to do some studying up to learn how to use these modules. They're certainly cheap enough if I accidentally fry them!
Trevor

 

[bushtech]

Just a caveat emptor.

I am using one of those TP4056 boards.


I find that they take a long time to charge a 18650 battery. Might check the charging current some time to see what it actually puts out

 

[Bluejets]

Just a caveat emptor.

I am using one of those TP4056 boards.
View attachment 42478

I find that they take a long time to charge a 18650 battery. Might check the charging current some time to see what it actually puts out

It's in the videos I linked to.