Laser question

So I have been looking at lasers for a while. Had a red af laser and wanted a green laser.

Not sure why one is better than another other than size so I ordered a barska laser. First it is giant really dont matter to me. Second we installing it with trying to figure out where to put the pressure bad I killed the battery just messing with it.

Figured it was just a cheap battery since it came with it so I replaced it (had a few at the house for my night vision) Was messing with it this morning for a few minutes and it killed the damn battery again.

Is my laser defective or does this giant laser just eat up batteries?

Thinking about sending it back if it chews up batteries in a few minutes of actually on time.