They charge without issue in my fourslot nitecore intellicharge i4 although after reading the literature that accompanies the charger i charge them in pairs and in alternate slots 13 or 24

Now although i purchased a pair rather than this fourpiece offer my review is posted here because the picture doesnt show if the batteries are flat top or button top unlike the two piece set in which the picture clearly shows them to be flat top

Would reccomend to any who have this device the most powerful 18650 on the market made by panasonic top brandthe battery lasts for a very long timeworks out to be the cheapestcurrently using it with my ecig joyetech evic works flawlessly having been prompted to buy the panasonic version of this battery after seeing more than one forums comments to the same effect i have been disappointed to find that as supplied they do not work or at least they will not work in this torch skyray king super bright 3x cree xml t6 led flashlight 4000lm led torch asin b00b6xtwd6the problem being that the positive electrode is at best flush and at worst retracted inside the outer plastic casing which in the case of two torches one them a resupply by a kind supplier trying to cure my nolight situation prevented any electrical contact from being made

I personally got around this by placing a blob of solder on the positive terminal to increase its length however that was my choice and it may well be far from safe to attempt such a repair exploding batterywise