@vaporsizer save a quid here http://www.vapegear.co.uk/product/luc
Not all nitecore chargers work, my first one was a dud and i think it damaged a lot of my good efest batteries.....
I had four i4's before I got a good one. They lasted a day or two and just packed up. Thankfully I only live 10 minutes from ECW where I got them. This last one is working a treat now.