I set mine up on Christmas day and still using the same batteries that came with it. So I imagine they must be getting low by now. Being right handed I assume that gets more use for me as I do tend to shoot rocks in Dead & Buried while waiting on players.. and I do tend to use my right/ dominant hand for that and also for throwing cards at the enemy players.
Probably in game as well - I imagine I shoot faster with my right.
Will be interesting to check - but Id be surprised if the right isn't lower than the left.
edit: (hand controllers)
I know this is an old thread, but I have this exact issue, and I'm left handed. My right touch drained a full battery in 2 days, not being used, while my left was still full. My right touch burns through batteries so fast that I've started just taking the battery out of it when I'm not playing.