Sennheiser BA 70 Rechargeable Battery Pack for EW-D Transmitters

The Sennheiser 508860 is a rechargeable battery pack known as the BA 70, designed to keep EW-D SK bodypack and EW-D SKM S handheld transmitters running without the hassle of swapping disposable cells. It replaces standard AA batteries and delivers stable power for performers, presenters, and engineers who depend on consistent wireless audio.

A 1720 mAh lithium ion cell inside the pack provides up to 12 hours of continuous operation, so you can cover soundcheck, rehearsal, and the show itself on a single charge. Because voltage remains steady throughout the cycle, audio quality stays uniform from the first track to the encore.

Recharging is straightforward. Place the BA 70 into the L70 USB dual charging station (sold separately) and it reaches full capacity in roughly three hours. This quick turnaround lets production crews rotate batteries during breaks and keeps entire transmitter fleets ready for action.

The battery maintains performance in temperatures from 14°F to 131°F. That range covers ceremonies held outdoors in the middle of winter, hot summer festivals, corporate conferences, and classroom lectures.

At 2.1 x 1.2 x 0.6 inches and only 1.2 oz, the BA 70 adds little bulk or weight, allowing handheld microphones to feel balanced and bodypacks to stay discreet on belts or costume pieces.

• 1720 mAh lithium ion battery pack made for EW-D SK bodypack and EW-D SKM S handheld transmitters
• Up to 12 hours of continuous use per charge
• Full recharge in about 3 hours with the L70 USB dual charging station (sold separately)
• Operates in ambient temperatures from 14°F to 131°F
• Physical size: 2.1 x 1.2 x 0.6 inches; weight: 1.2 oz
• Reduces disposable battery waste while providing consistent voltage for reliable audio