I have had my Move for a few weeks now and I find the battery life to be terrible.  I don't know if that is because I tend to leave it on the base.  I love the speaker but the battery only lasts a couple of hours before it is depleted.  Anyone else seeing this?

I have had my move for several weeks as well and use it roughly three or four times a week.

In the first two weeks of use the battery would reduce by about 55 to 65% too 35% of remaining charge with moderate volume, volume level 3 to 4 requested of Alexa, and that is for 6 hours of continuous use.

Now it is around 45% reduction down to 55% of remaining charge over the 6 hour continuous use period, so it does appear the battery is becoming more efficient in my case. 
I will however closely monitor the battery charge and let you know if there are any changes.
 

My Sonos Move is two weeks old and so far the battery life is disappointing. The best I can achieve is about three one hour sessions between charges. Not as advertised! 

It sounds like the battery may have an issue.

My Move is now several months old and I listen at a volume level between 3 to 4 (Using Alexa to increase or lower the volume) and I often get well over 7 to 8 hours and still have 40% of the battery life.

Perhaps try putting it on the cradle to charge and press the power button and hold it 5 seconds plus until you witness the lights turn off and the speaker shut down.

Then after about 5 hours start up the Move and check to see if it shows 100% charged in the Sonos App. Then use it and see if the charge lasts longer.