All the lumens! but slightly short on battery life - Petzl Actik Core 600 Lumens Headlamp

This headlight really packs a lot of light when run at full brightness. The downside is that full brightness mode seems to only last a couple of hours. The next mode down from that is pretty dim in my opinion if you are trying to navigate uneven terrain. I have only used the rechargeable pack so far. I am curious if it will last longer with triple-A batteries. I have another Black Diamond headlight that will slowly, incrementally dim as the batteries run low so you can get a solid 8ish hours out of it at a pretty good brightness before it gets really dim. I think having only certain modes on the Actik takes away this ability