Spotlight Security Cam with two batteriesc

Everytime I have to change the batteries and I replace the drained ones with two fully charged batteries, only one shows as charged and working. The other shows as greyed out (the one on the left side icon). I have tried various fully charged batteries and the same thing happens. So even though I have two fully charged batteries, only one is used. When the one that shows is drained the camera goes dead. Any ideas?