Fuel cells began to become commercial in a variety of applications in 2007, when they started to be sold to end-users with written warranties and service capability, and met the codes and standards of the markets in which they were sold. As such, a number of market segments became demand driven, rather than being characterised by oversupply and overcapacity. In particular, thousands of PEMFC and DMFC auxiliary power units (APU) were commercialised in leisure applications, such as boats and campervans, with similarly large numbers of micro fuel cell units being sold in the portable sector in toys and educational kits. Demand from the military also saw hundreds of DMFC and PEMFC portable power units put into service for infantry soldiers, where they provided power to communications and surveillance equipment and reduced the burden on the dismounted solider of carrying heavy battery packs.