Ring camera charger hissing

My battery charger for the ring camera makes a high pitched humming ringing sizzle sound. Hard to explain but high pitch when charging the batteries for the camera. Why? Are the batteries going to be explode? Do I need a new charger? New batteries?

Hi @Msidbury. @SolarEclipse is correct, it should not be making that sound. If possible, try to capture this on video so I can share it with my team to examine more closely. You can upload the video here, or onto YouTube, then share the link here. Thank you.