A battery charging device for simultaneously charging the cells of a multi-cell battery in parallel wherein an induction coil distributes and isolates the charging energy to each cell. Preferred lighting fixtures are recessed lighting fixtures adapted for ceiling mounting. The non-linear optical material has an asymmetrical carbon atom and a cyclic group. The extendable initiator cup is at least partially disposed within a longitudinally extending bore of the support housing. The collar may be removable and may also include a handle.