My battery is going down very fast! From 100% until 0% it takes about 6-7 hours without using any apps on my watch (but I have installed several). No app is in my dock. Compared to last beta: I used my watch two days before I had to recharge.
Battery life of watchOS3 beta2
I am having the same issue since updating to 3.1.3 (14S959) beta.