I use rechargeables for my AA machines. No they won't last as long as a set of alkalines, but I get what seems like unlimited charges out of them.
I use them for a hunt, then recharge before next hunt.
Or get enough for 2 sets and then you can run them longer without worrying about running dead in the middle of a hunt. However, I don't think you can kill a fully charged set in one hunt. I never have. And if you too them off when you get home or before going out again, they're always full.
Eneloop white (or special edition colors all besides black) say you can get 2100 recharges. That's like 40 years if charged once a week lol. So 8 years if you charge 5x a week or so.
Curious if you have a Tejon and run them. If so do you get the 8 beeps on startup?