Cheap Li-ion charger.

Kevin Tan

Enlightened
Joined
Jun 22, 2001
Messages
442
Location
Malaysia
Went to Sabahoceanic and got 2x17670 but cannot find the charger for it. So went back home, dug out the old Nokia 3110 li-ion batt pack to get the protection circuit. Got a cheap dual desktop charger for the same fone. Dismanteled the desktop charger and soldered the 3 wired contact to the protection circuit. Got a piece of 2x4 wood and used a nail as the +ve and a battery serial connector plate from a cheap rc car, bent the plate and anchored the +ve with 2 small screws and used the spring as +ve. solder 2 wire to protection circuit batt tabs ( the tabs are soldered to circuit and welded to batt) connec the wires from the circuit to contacts, plug in supply and success!!!

It took 6.5hrs to charge a piece of 17670 to 4.25V at which point the desktop charger indicator changed gradually from red to green. My supply is rates as 4.5V 300ma.
 

koala

Flashlight Enthusiast
Joined
Mar 5, 2003
Messages
2,295
Location
Melbourne, Australia
Kevin,
I did try your trick to remove the existing prismatic battery of the nokia and actually use the mobile itself to charge the Li-Ions but they seems to take forever.

Another charger you want to try out if you like to DIY build your own..

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB6&Number=320252&Forum=UBB6&Words=&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=allposts&Main=320252&Search=true#Post320252

CM is also playing with one from Linear if I am not wrong. His requires less components. If I memory serve me correct...
 

Kevin Tan

Enlightened
Joined
Jun 22, 2001
Messages
442
Location
Malaysia
Nukiez, I have a few models of the Nokia wall wart. Some of them especially the lightweight one put out a lot more mAh and do charge the fones faster. Since I only use 1x17670 at a time I don't mind the long charge time. Plus the batt never even warms up to touch.
 

koala

Flashlight Enthusiast
Joined
Mar 5, 2003
Messages
2,295
Location
Melbourne, Australia
Yes Li-Ion should stay cool when charging.

I am doing a total discharge(<0.1v) on an old laptop 18650 1300mAh and see what will happen. It took the first charging stage(charge at 1/10C) without a problem. Now it's 3.0v at second stage, 1C charging. I wonder if it will hold more or less charge after this.

This is actually a cell that I revived, initially it refuse to accept any charge but after a few charge and discharge cycle it's working fine. Hopefully it will survive the crazy test.

Vince.
 
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