Protmex PT622A Digital Sound Level Meter - 30-130 dB Decibel Reader with Large LCD Display, ±1.5dB Accuracy, Fast/Slow Mode Selection - Perfect for Home, Workplace, and Industrial Noise Measurement

I purchased the unit and the battery symbol says that if you see only one little triangle then the batteries need to be replaced. I put in new batteries and it still says I need to replace batteries. I tried two sets and the unit shows low batteries. I haven’t tested it in use long hours but it bothers me that it shows low battery all the time