Ring outdoor siren does'nt recognise rechargeable battery

I originally set up my outdoor siren with the D-batteries that came with the package, having only finding out after installation that the ring siren requires another power source to enable the dusk/dawn feature I purchased the ring rechargeable battery. After fully charging the battery I installed the battery in my Siren only to find the battery has not been recognised as being installed......any help would be appreciated thanks