Cheap LiIon charger with Samsung Travel charger for mobile phone (TCH137)

I received my TK35 before the 18650 batteries and the proper charger. I wanted to use the TK35 so I scavenged a few 18650 from a PC battery pack and started to charge them with a lab power supply (CC then CV to 4.2V) OK but not very convenient.

Looking through my collection of mobile phone chargers, I came across a Samsung Travel charger ref TCH137 supposed to deliver 4.2V , 650mA. Quite uncommon, besides it has a big plug with Led indicator to hook up to the phone. I opened this plug and noticed among others, a chip labeled 6292. A quick search to find out it was an Intersil ISL6292B designed to charge LiIon batteries !

Great,! I spent some time reading the specs, then it was just a matter of ½ hour to locate the pins and wiring to the mobile. One V+ (in fact two pins connected together), one ground, an enable pin, an unused pin. An other ½ hour to solder the En and Gnd together, then the required wires + and Gnd fitted with magnets to attach to the 18650.






When you look at the plug, LEDs side towards you, phone side up, (so you can read Samsung), the V+ are the two pins close together on the left, next the En and Gnd to solder together. The pin on the right is unused.





Great charger, the Led gives you the charging status (all as per Intersil spec).



Uploaded with ImageShack.us

PS: 30 years since I had worked with Intersil chips !

This is very, very cool, and I am surprised there isn't more info on CPF about this.

How hard was it for you to do the wiring?

Any photos of your handiwork?

Re added picture. The whole thread dissapeared with The Big One

I made two of them. At 5€ a piece, hard to beat. Besides they really comply to LiIon recommended charging method as can be seen from Intersil specifications.

This thread was gone when my charger arrived. Nice to have it back.
Thanks BoarHunter.

I remember reading this long before I got my first Li Ions. I bought one of these chargers immediatly! What's the procedure for soldering the terminals? I know you have a pic but could you give us a quick write up?

Brian10962001 said:

I remember reading this long before I got my first Li Ions. I bought one of these chargers immediatly! What's the procedure for soldering the terminals? I know you have a pic but could you give us a quick write up?

Click to expand...

Remove the two screws and just pry open the plug, pull the part containing the pins. Shorten the pins by about 2 - 3mm, solder wires as on the photo to the pins. Red is +, black is -. Note that the enable and - pins have to be soldered together to the black wire. Drill (1.5mm) the grey plastic part to accomodate the wire and soldered pins. Terminate the wires as you wish, magnet or hook it up to a cradle.


The second picture shows a different set up as I have installed a berg connector in order to be able to use various adapters.

I soldered the bottom pin as in your pic to the positive, and moved the pin next to it over the the middle pin for ground. I get the green light, but it won't charge? Does anything need to be done with the 4th pin at the top?

WHOOPS scratch that, my 18650's just kick more @ss than I thought, despite being in the flashlights and me playing with the modes about 100 times over the last few months both of them were still too full to start the charge, I've got a Ultrafire 18350 on it now and the red light lit as soon as I connected it.

Is there an easy way to reduce the current output for this charger to around 500 ma or less for smaller batteries?

kking said:

Is there an easy way to reduce the current output for this charger to around 500 ma or less for smaller batteries?

Click to expand...

No but 650mA is OK for 14500 size. For Liion charge current should be between 0.5 and 1C so should be OK for RCR123 too.

Hi! I love it the solution. I would like to ask it exactly which foot it would be necessary to solder how? The underwear 1 foot the positive one. Is it necessary to join the two middle ones? Is it the negative? Is the picture correctly?
I say thank you the answer, an apology for the spelling.

Tested, but unfortunately 2,14V switches off. :shakehead

The two plus prongs are close to each other, just solder the red + wire to the them. For the - and Enable prongs, just bend as shown and older a black wire to them.

2.14 V ?
I made two, when done, the batteries are at 4.17V. Which is good and safe. There is always a slight V drop when the battery is disconnected from the charger.
Poor contact to the battery can also lead to early cut off.

I miswrote it. Not 2,14V but 4,14V. I did the soldering now and 4,16V.

--
Whether Samsung TAD137ESE charger (5.0V - 0.7A) inapposite the to 18650?

very nice brother .. do u know of any other charger using which can be adopted for this purpose ? because i have difficulty in finding it in local market here in afghanistan,,, and ordering it online is expensive and will null the idea of cheap yet reliable charger ,,

if any one comes accross it i wil be glade to know about it..
meanwhile @OP can i use any charger that is using this ic ?

also can u post the pic of the charger where the model number is written? or whats the exact model number ? is it only TCH 137 ? or are there any other characters in the model number ?
thanks

i today purchased 2 samsung chargers both lack the above ic,,

model no are
TAD037UBE

AND
TAD137UBE

today again i purchased another samsung charger tch137ube and i opened its connector i found different chip on it..
it was labelled 94bcrz h522wa ? what is it ? its outputis 4.2v 650mA...
can i mod it somehow ?

@OP please can u mention the exact model of the charger that u modded ? as there are a lot of tch137 chargers....

thanks

In Soviet russia i again purchaased TCH137USE but found same bool sheet chip labelled 92bcrz
but its ouptu is 4.2v 650ma can i smod it somehow ?

USSR said:

today again i purchased another samsung charger tch137ube and i opened its connector i found different chip on it..
it was labelled 94bcrz h522wa ? what is it ? its outputis 4.2v 650mA...
can i mod it somehow ?

@OP please can u mention the exact model of the charger that u modded ? as there are a lot of tch137 chargers....

thanks

Click to expand...

oops my bad.. i today again checked this tch137ube charger it also has 92BCRZ ic it has intersil logo.. though not sure if its the liion charger ic..

i have followed like op did and so far the light is red indicating the cell is gettinbg charged. the current flow is 550ma and i removed the cell to check its voltage.. its 4.04 volts .. it is a 'cell' from a cell phone battery,, i had removed the protection circuit..its just bare cell.. prismatic

now i again removed the cell from the charger to check its voltage t is 4.17 still the light is red .. hahahaha as i typed the word red the light turned green indication it has charged the cell. awesomeness.. thanks BoarHunter.. now the voltagee is 4.16

92BCRZ is one of the markings found on the Intersil ISL6292 charging chip. Congrats!