Re earlier replies:
I have used Ni-cads in Maglites for about 15 years with no problems and I find it also avoids any corrosion problems too.
Whatever you say about the varying Mains voltages may be correct, but a mains rechargable maglight gives a very much brighter light than 'normal' ones and is very much more useful tool for engineers/mechanics work.
Last price for a rechargeable checked at about $140 (US) but I believe it is available from the UK distributors.