Here Are Some Useful Tips For Using Wireless Microphones
If your microphone uses multiple batteries, change all of them at the same time.
Keep your lavalier mics dry. Dry them completely before storing.
Always use alkaline or NiMH batteries. Carbon batteries will fail quickly.
Remove batteries from transmitters that will be stored for long periods of time.
Choose lavalier placements that will not rub against clothing or hair
Secure excess lavalier cable with a twist tie to prevent tangling.