Battery life since last update

Hi

My Instinct, owned for 3 months, notified it had been updated last week (I think) and since then the battery life has been only two days.  Software version is 5.10.

I haven't used the GPS function in the last month and just use it at the gym on the treadmill for 30 mins at a time twice a week.

Is this an issue others have experienced?

Thanks in advance

Matt