Battery Lasts few days with Basilisk X Hyperspeed Mouse

I've had a Basilisk X Hyperspeed for 15 months now. In the last 2 weeks or so, it feels like it is draining the battery super fast or at least the hardware thinks it is. I just put in a new Duracell AA a week ago, as the low battery message was appearing and 5 days later I got the same message. I put in another fresh battery yesterday and today the low battery message appeared again. I've tried the Razer support guidance about checking the firmware is up to date and that Windows (11 in my case) is up to date and they were already up to date. I usually connect using 2.4ghz wireless rather than bluetooth but when following the support procedure for checking firmware it said to connect via BT. When I did I noticed the PC telling me battery was at 13% despite only being put in the previous day.

Anyone else experienced similar recently and have a resolution. Previously the battery had lasted months.