Charges 1x NiMh or Li-ion, and power banks Li-ions (and MacGyver’d NiMh ) back to USB. Charger has been review by HKJ at lygte-info.dk – it’s well worth reading because this charger is on the high current (1A), high voltage (~4.2-4.3V) side. I wouldn’t use it with low quality cells or small cells (AAA Eneloops and 16340s being borderline), and even then, I would pull the cell off early, before full charge, and not make a regular practice out of it. I primarily use AA Eneloops for my gadgets and Keeppower 16650s (based on Sanyo’s 4.35V cell) for my Quarks, so they’ll work well with this charger. Tiny, $10, <2oz, and adds quite a bit of versatility to my EDC rig .