Thanks Norm. Those chargers look pretty fancy to me and cost too much for me.
I am looking more in the price range and design of the WF-138
http://www.dealextreme.com/details.dx/sku.1236 .
Alternatively, since I already have the WF-138 (charges CR123A LiFePo4 and regular Li-ions), I guess I could modify it to fit a 18650. Now if I could find a 18650 battery holder.
Perhaps this system will work:
https://www.candlepowerforums.com/threads/89363
Since the WF doesn't have banana jacks, I suggest you cut a piece of roughly 10-15 mm diameter wooden dowel (or a rectangular bar of wood hacked out of a bigger piece with a saw) to length = 34 mm - 2 x (height of brass screw heads + washer, if used) - nominal thickness of wire, if clamped under screw or washer, and screw the wires onto either end to make an adapter to plug into the charger. This crude module should fit into the charger in place of a 16340 cell and pick up the circuit for the leads mounted on the clamp. Hope that makes sense.
You can solder the wires to the screws as shown on the clamp, but I'd be inclined to just clamp them under the screw heads and maybe a washer. Soldering to the *washers* might be the easiest for installation. Be sure to use less than 15 mm long screws! Also, be REAL careful to get the polarity correct every time.
I have no idea if it is safe to charge a larger battery with the wf-138, so get a second opinion before you do this! I think I read on an AW thread that it is CC/CV so the CC phase seems harmless enough, not sure what will happen at CV. I don't trust cheap Li batteries or their chargers, so I charge mine in a big, thick ceramic flowerpot, on the assumption that it can contain the fire if things don't turn out according to plan.
I am fairly sure that at the low current of that charger, "monster wire" is going to be a big waste of copper. Use whatever you have that's substantially thicker than your hair.
