Charging Lions using cell phone chargers.

[Ledean]

I do not know if this has been posted before.javascript:void(0)
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Has anybody tried using these chargers to charge the lions battery.
The charger has four terminals, and it cuts off if it is just connected to the battery without the protection circuit. I think the other terminals are to monitor the battery voltage. When i tried to connect them it goes off.
Can we get a 4.2 volt output without the circuit getting shut off.
Thanks for any response.

 

[TrueBlue]

Yup, I do it all the time.

 

[greenLED]

could we have details of your setup, haveblue?

 

[Doug S]

[ QUOTE ]
Ledean said:
Thanks for any response.

[/ QUOTE ]
Not all cell phone chargers are the same. The chargers are matched to the pack design. There is no "one size fits all" answer to your question. *Many* single cell phone chargers put out too high of a voltage for use with an unprotected cell. Those two extra terminals may be for an in-pack thermistor. Try connecting those two terminals with a 10K resistor and see if your pack then produces output.

 

[greenLED]

I have access to the charger haveblue is using (at least the one in his pic)

 

[Ledean]

Dougs
Tried connecting a 10k resistor. Actually i did not have a 10 k so i out a 6.8k instead. Dosn't seem to work. I do get voltage when i connect the multimeter but i guess there is hardly any current . Tried all types of combination with the 4 terminals. Maybe they only work if the cells are protected or something.
Ledean

 

[Ledean]

Haveblue,
What is that charger you are using if i may ask ?.
Ledean

 

[Doug Owen]

This is backwards, IMO. The way the question is posed, it's clear that the charger is an *unknown*. Charging Li cells with unknown power sources is known to be risky.

It can only be safe with a *well designed* circuit specifically designed to charge that particular cell.

FWIW, my cell phone chargers (at least the last two) are 'dumb' and depend of the phone to control charging. The one before had a slot on the charger base next to the phone connector that had a circuit to charge a loose cell. In that case, I'd say charging that cell with that charger is safe. Anything else is a risk, small or large. Being as folks can get hurt (and set their digs on fire and get to meet the guys with the big red truck and spotted dog....), utmost caution in the advice we give in this area seems in order?

If you're not sure, you shouldn't be messin' here. And if you're askin', you ain't sure.....

Doug Owen

 

[jtheodas]

How about this charger?
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=1268

 

[SilverFox]

Hello Jtheodas,

I have no need for the ability to charge up a cell phone battery pack, so I went with this.

There is a typo where they say it charges cells up to 4.5 volts. The open circuit voltage for one cell is 4.2 volts.

The one you listed would be good for cell phone packs and single Li-Ion or Li-Poly cells. The one I listed will also work on cell phone packs, but is not as convenient (you need to figure out which tab is positive and use the clips), and will work on up to 4 cell packs.

Tom