Battery drain after V4 update

I updated yesterday, and since then the watch has drained significantly faster than before.

Yesterday I drained from 100% to 35% just having it as a watch during the day and recording 1 activity (without phone GPS) for an hour.

Today over the same time period it has gone from 100% to 60% just using it as a watch - no syncing or activities recorded, not connected to my phone by Bluetooth.

I could previously use it for at least 4 days, recording activities both with and without phone GPS and syncing at least once a day. Now it appears that I have to charge it every day.

Not impressed Garmin, please sort this out.