Suspected defective battery

Hello, I suspect I have a problem with the rechargeable battery for my recently purchased 3rd gen Stickup Cam. I charged my battery to 100% using my orange cable; the camera slowly drains, then drains exponentially to zero. I also have a solar panel that seemed to charge the battery during the day (nearly to 100%), then the same thing happens with a slow drain, then quickly to zero when the sun goes down. I unplugged the solar panel and again recharged the battery with the orange cable, installed it, and it drained in the same manner as above. Unless I missed something, I'm thinking my battery is defective; I purchased the cam on Amazon on 26 Apr 23. Help! v/r, Biggs