Procell Constant cells in trade boxes of ten: AA (LR6), AAA (LR03) and 9V PP3, the formats that radio microphones, IEM packs, pedals and active DI boxes actually eat. Procell Constant is Duracell’s professional alkaline range, engineered for devices that draw a steady current over long periods, rated for operation from -20C to +54C and built to ANSI and IEC specifications, which is exactly the duty cycle of a wireless transmitter left on through a show.

Buy by the show rather than the unit: a busy weekend of wireless work gets through cells faster than expected, and fresh batteries at soundcheck are cheaper than a dead vocal mic mid-set. Standardise on one format across the wireless fleet where possible so spares stay interchangeable, keep 9V stock for older packs and test gear, and let box quantities keep the per-cell cost sensible for hire and production use.