The Wall Lenk FX3 heats up well enough for a cordless/rechargeable soldering iron, and the battery seems to have a decent charge. As for internal battery life, only time will tell. My main criticism of this device is that the tips are expensive, relatively difficult to find, and fairly limited in the types available. At the time of writing this review, I believed there were three tips: a tapered tip, a hot knife tip, and a shrink tip.