possible do charge 18650 with this?

[zband]

I revieved this cheap charger from the battery station a while ago

pic here : http://www.alibaba.com/product-free/11159507/Cr123a_Battery_Charger/showimage.html

tem# : PH-123A-A
Input: 12V D.C 250mA
Output: 4. 2V D.C 360mA
Characteristic:
1. Suitable for 2pcs RCR123A Li-ion battery
2. Charge with constant current and voltage
3. LED indicator
Red led=batteries are properly charging
Red LED turn to green=batteries are fully charged
Green LED =power is on
if there is no batteries be detected in the battery compartment
Car adapter available (optional)
Dimension: 84 (L) x 46 (W) x 30 (H) mm
Weight approx: 50g

I did a test using my maha 777 plus on an unprotectected rcr123 battery - it cut off at 4.29V. Reading other posts apparently this is too high for a lithium ion battery. So I drained this battery and tried to charge on the cheap charger above, and it cut off at 4.19 volts - a better number.

I have made an investment in a couple 18650 protected AW's and would like to know would it be safer to charge them on the cheaper charger, even thought this charger was designed for rcr123 batteries?

 

[Monocrom]

If the charger is specifically designed for RCR123 cells, how would you even be able to fit an 18650 into it?

 

[zband]

Sorry - I should have been more clear - I was going to solder on some wires.

 

[Monocrom]

Sorry - I should have been more clear - I was going to solder on some wires.

You want to solder wires directly onto the 18650 cell?

That doesn't sound like a good idea. There's a reason why 18650 and other such cells are not generally sold to the Public. I haven't had any problems with my AW 18650 Protected cells. But you really should use a charger specifically designed for 18650s.

I can understand if cost is an issue. I use an inexpensive Ultrafire WF-139 charger for my 18650s. It doesn't have a lot of bells & whistles, and you have to check it periodically since it'll continue to trickle charge the cells after they are full. But mine works reliably. Check out the link.

LINK ~ http://www.lighthound.com/index.asp?PageAction=VIEWPROD&ProdID=2566

 

[zband]

not on to the battery, rather on to the unit. It seems that a charger designed for a Li-ion battery will be designed to cut off at around 4.2V, regardless of capacity. In the case of the 18650's I would think it would just take longer to charge. 250mA seems like a safe rate.

Just trying to avoid overcharging, which the maha can does ....

 

[Monocrom]

Must admit, I'm having a hard time trying to visualize how you'd get the wires to stay on the ends of the 18650. So you solder the wires onto the unit, then the other ends of the wires go on the ends of the 18650. How do they stay on the ends of the cell? :thinking:

 

[Tohuwabohu]

 

[IMSabbel]

Should be no problem, although it might take a bit of patience, considering you will be charging at less than 0.2C

 

[Sabrewolf]

Why not use those small rare-earth magnets? I use them all the
time for quick battery coonections and testing things

 

[IMSabbel]

I did use them, too, for test. I noticed that if you are quick, you can even solder wire onto the small DX ones (7x1mm) without demagnetizing them too much.

But i wouldnt want to use them for hour-long unattented charging (i had a short over 12 Eneloops becase the two magnets thought its cool to snap together once. Might be ugly if unattented...)

 

[lightforce2]

(i had a short over 12 Eneloops becase the two magnets thought its cool to snap together once. Might be ugly if unattented...)

place a fuse in the circuit

 

[mdocod]

I did a test using my maha 777 plus on an unprotectected rcr123 battery - it cut off at 4.29V.

If the maha 777 plus is terminating li-ion at 4.29V, I would personally be contacting MAHA about that. They are a fairly highly regarded manufacture and I would expect better from them. Maybe they have an explanation, or maybe the charge termination is somehow user adjustable for li-ion?

Eric

 

[Fallingwater]

It can definitely be done; I did something similar a while ago, and it worked. Downsides: it would take most of a day to charge a single 18650 and would slightly overcharge if left unattended.

 

[Monocrom]

You learn something new everyday.