Grasshopper battery life-just checking in with other owners

I have a new unit, 2 batteries. I'm finding that I get about 8 total draws per battery-long, good draws, but just @ 8.

Is this normal? I feel like others are talking about how they get 3 bowls full, and it takes me at least 4 hits to cash a decently filled bowl, so I'm curious if my unit is faulty in some way.