General-purpose NiCd battery charger

There is a wide variety of NiCd (nickel-cadmium) battery chargers on the market, but there are not many that can work from an incar 12 V cigar lighter. Such a charger would, for instance, be of interest to campers and caravanners who do not have a 230 V a.c. mains supply available. To satisfy the needs of these users, a charger could be designed for operation from the cigar lighter, but it is, of course, of far greater interest if it could also work from the domestic mains supply. Furthermore, it would also be very useful if a number of cells, say, 1 to 4, of different format could be charged simultaneously. Lastly, another benefit would be if the charger would automatically switch off once the battery or cells have been charged fully.