I imagine that depth and shooting through the hull or not matters a little too. I went with same same battery pack I used last year. This year I had it on pretty much any time I was on a lake and I got another 8 days @ easily 6 hours per day out of it. The low battery alarm went off on Shelly. So the new set went from Shelly to Pickerel where I ran into Jimbo. I ended up camping with them and dopey me forgot to turn the darn thing off.

So twice now I've killed a set of batteries pinging the moon all night. I can only assume it's going full blast trying to get a return and w/o water, that ain't happening so trying at full blast kills the batteries overnight.