That’s because the Voyager series like my HP-15C used silicon-on-sapphire technology originally developed for the space industry, which is why it will run a decade on a single change of batteries.

The SwissMicros are nowhere near the same class, no modern electronics are.

I heard a story that might be apocryphal that the Voyager series were specified to not need a battery change for "at least a year" and it was misinterpreted as 1 year of power-on time.

But both my 32s and 35s both had "pretty good" battery life.

I bought my HP-15C in 1987. It only recently got its third set of batteries.

I have a DM42 and have had it a few years. I haven’t had to replace the battery yet. There are times when I used it everyday, and times I leave it sitting on the shelf for months. I also have an HP42, and it eats batteries. I assume it has a fault.

I have a DM42 (which I absolutely love) and to be honest I'm a bit disappointed in battery life. I think it lasts a few weeks at best, and I know the battery is almost done when it starts resetting to the splash screen with a beep when I turn it on. The easy workaround for me, since it basically stays on my desk all the time, is to leave it plugged into a USP port. I noticed another comment saying the battery life is excellent so maybe mine has an issue, or my custom SI units program/menu sucks down the battery life!