batteries only produce between 1,000 and 2,000 flashes (depending on the power level selected) and the fact that these flash batteries were not rechargeable led to professionals replacing these flashes with other models that were powered by batteries that could be recharged. Current repairs and updates There is a company that has developed a rechargeable power supply for the Stroboflash II, III, and IV, which plugs right into the Stroboflash power pack instead of the original dry cell batteries and uses two 12 volt rechargeable battery packs. They also repair these flashes. This can be found at Stroboflash.com. Sources Graflex.org, particularly: http://graflex.org/graflex-products-list.html Stroboflash.com, particularly: http://www.stroboflash.com/Stroboflash/Stroboflash_Main.html History of Technology, more particularly: http://www.uwgb.edu/Library/spc/findingAids/technology.pdf Flash photography Photographic lighting