My first digital multimeter was a Micronta....here it is, fresh from my museum archives:
I remember being very impressed with its long battery life when I was using it decades ago, probably because it didn't use LEDs. But now I just turned it on and it powered right up, so I checked the batteries and they look pristine. The absolutely astounding thing is I believe these are the original Radio Shack Enercell Extra Life batteries bought when the meter was new! More than 3 decades ago! I did hang out at Radio Shack in the 70's and 80's but I definitely haven't bought batteries at Radio Shack for decades. I just measured the voltages at 1.54 V and 1.539 V.
Count me astonished, gobsmacked, flabergasted and totally blown away at how they can still be in this pristine condition. On the batteries it says they have a "miracle seal" - that is obviously not just hype. I have never seen any AA batteries sit on a shelf for a decade without dying and spewing their guts all over the battery compartment. I am going to have to see if these batteries are still in production - they are truly spectacular.