18650 Battery fit

I have a EC4SW light I just got, along with two INR25r cells, unprotected. They don't seem to be long enough to contact the spring. A pair of flat top cells are long enough to work. Are flat top cells long enough for this light? I don't have magnets at hand to modify the cells. Thanks for listening to my newb question.

I have the same problem with my EC4S. I have been using Nitecore protected cells that work fine, but I am looking for something that might perform better than the older Panasonic B's in the Nitecore cells. I think that you either have to stretch the springs a little, get some magnets or buy some longer cells that will fill the space.

Most Nitecore lights require a button top cell.

Magnets or soldered copper or brass pill to positive contact

Unprotected cells are not that expensive.
I'd get ones with the button top already attached as opposed to solder/pills.

I have had no problem just adding a little blob of solder on top, no extra part needed. The trick is to prep carefully - clean and with a thin film of flux. Make sure the iron is hot, loaded with enough solder and CLEAN (shiny solder - if it gets dull, wipe on a wet sponge). Get on and off quickly so there is not time for heat to soak in to the cell and do damage.

I hate using magnets, they can shift during assembly (worse on a twisty, they are always getting wiggled) and cause a short. Ask me how I know. They are not a problem down in the negative end, there is not positive contact to short to. But when used at the top to negotiate a polarity protection pocket, no thanks, just get the button top battery or add solder if you are comfortable with your soldering skills.

Just adding solder can be dangerous in high drain lights as they might end up soldered to the spring

Hmm... Interesting concept. I don't have anything that pulls that kind of current, but I would think that if the top of the battery is getting hot enough to melt solder during operation of the light, you have WAY bigger problems than the battery getting stuck to the spring/PCB. Of course, soldering a piece of copper on also means that scenario would result in a loose piece of copper.

I use keeppower (Sanyo) button top protected 18650GA cells in my ec4sw http://www.illumn.com/18650-keeppower-3500mah-sanyo-ncr18650ga-protected-button-top.html