Take care with the lights you're buying. A couple of the cheapie chargers that I've had with cheapie lights have caused problems. NEVER leave them unattended, seriously, don't. I've had one melt and one explode. The explosive one wasn't fun. Buy from a reputable supplier, a few extra quid must surely be worth it for your house or life.
I now only use my good uk lights and batteries, the headlamp units from cheap sets still work with other battery kits.