While some of the eBay auctions for the Klarus XT2C I picked up came with their own 18650 batteries and chargers, I had not quite finished researching them so didn’t want to jump into a rash decision. Some of the packaged 18650 batteries were the Ultrafire brand and from reading more on Candlepower forums, there are some knockoffs out there that were not “true” Utrafires. There also appears to be a “good” charger that correctly uses a CC/CV charging method, and a crappier version of charger that follows a more conventional charging method. The CC/CV ones are not the majority out there, neither are the “good” batteries, as those are typically sold to battery pack makers and manufacturers like Tesla to power electric vehicles. High capacity li-ion batteries are in very high demand. To make things more difficult, unprotected cells let themselves get discharged or overcharged enough to damage themselves, whereas protected cells protected themselves. The good unprotected ones come from brand names like Samsung, LG, Panasonic, etc. The good protected ones come from non-brand names like AW, Redilast, etc. If you’re doing a multicell flashlight or if you’re absent minded, you should probably go with a protected cell. You can go unprotected and get more capacity for less money, but there’s always that risk you might just make an inadvertent pipe bomb with your fancy high capacity li-ion cells stuffed into your sealed aluminum flashlight.
Finding 18650 batteries turned into a bit of a problem for me, because finding a good battery and charger place that’d ship to Canada for a reasonable price was damn hard. Locally, there was NOTHING! I checked battery world, The Source (Canada’s Radio Shack), everywhere. And let me save you some trouble in case you go looking for it: everyone that has 18650’s has a kinda junky ecommerce website. None of the websites that I came across really exuded a confident buying experience. But one definitely rose above the rest in the ways that counted: onlybatteries.com. I noticed that they sold unprotected cells from decent brands, and the non-good chargers, added a few to my cart and checked what shipping would cost. Then I left, and they did something that only pro ecommerce sites do: they followed up.
Since they use a 2 part shopping cart checkout, they’re able to capture some of the shopper’s info and follow up on non-purchases, a technique called shopping cart abandonment recovery. The very fact that they did that flagged them as professionals and gave me a good feel that they’d ship on time and would stand behind their product. Keep in mind, I’m in internet marketing so I approach these things a bit differently that other people might. The hunch was right. I ordered on a Friday and had the batteries at my house by Wednesday. When I received the package, I was surprised to learn that the company had shipped from Montreal. The company has US and Canadian offices. I’m not so patriotic that I strive to buy from only Canadian companies, but I can appreciate where taxes can be saved and shipping speed can be increased.
Enough gushing about how much I love a fast painless transaction and onto the batteries! I bought unprotected 2800 mAh LG cells and a bundled charger for about $50 with shipping. I don’t believe the charger is the “better” CC/CV type, but I’m not sure this is a super big deal because even respected battery dealers like AW were selling the regular type. Would the CC/CV type give me better lifespan? Probably. Will battery technology be 50% better by the time my batteries die anyways? I’ll bet on it.
Right out of the package, the batteries measured 3.79V, which I hear is good. They’re a lot thicker than the CR123 batteries that you can also use in many of these flashlights, and they give a better fit. I couldn’t find my dial calipers or micrometer, so I used an adjustable wrench to give a quick idea of the size difference: not a lot, but enough that the CR123’s rattle just a bit in the flashlight body compared to the 18650’s.
After checking voltage, I put the batteries into the charger and checked voltage again. I saw .02V to .03V more than resting voltage applied, and the batteries never heated up a bit while charging. (Though, I don’t know if this is even important)
I know that some people, myself included, wondered if the flashlight would get brighter using the 18650 batteries rather than the CR123’s. I’m afraid the answer is “no”. Since the Klarus XT2C is regulated, as long as the batteries meet a minimum Volts X Amps, the flashlight will pump out the right amount of light. If you think otherwise, let me know which of the below images are of the flashlight using CR123’s, and which are of the flashlight using fully charged 18650’s.