I always recommend a [FONT=&]NiCore intellicharger Charger[/FONT] i2 I have an i4 and its the business.
I also have a Efest BIO V2 Intelligent Charger which I take on holiday as it also has two usb ports for charging phones, this is handy in hotel rooms which for some reason never have enough plug points to charge my batteries and charge two mobile phones and variouss tablets