Energizer alkaline batteries industrial aa aaa c cell d cell pp3 type energizer energizer en22 the energiser en22 is a 9v pp3 type industrial battery that has been designed to meet the most stringent needs of todays high drain devices and are available in the most popular standard sizes the energizer industrial alkaline battery offers an economical high rate source of portable power this heavy duty battery operates well in extreme temperatures and will retain 85 of its orig