With refurbishment, the original housing and wiring is reused. The interior is new, with long-life batteries, new electronics, and a LED light source. You can upgrade the luminaires and connect them with a central control system without having to add or change any wiring. Old fluorescent luminaires are usually designed for NiCd (Nickel Cadmium) batteries. If you switch to LED, you also benefit from the advantages of non-toxic NiMH (Nickel Metal Hydride) batteries.