To start by directly answering your question, I don’t have any comparative data on 1632 batteries, so I can only go by what I know so far with 2032s and with that, I’d go Duracell.
I have several optics that take 1632 batteries ( couple 509Ts, a 507C, and a 507K) but since they’re not identical, I can’t do a valid test. I’ve been meaning to reach out to manufacturers to see if they’d supply multiple T&E optics for the sole purpose of a battery-life test (no mounting or shooting) but that’s not within the normal T&E realm, so I’m not sure how excited companies would be. Add to that I’ve been really busy with creating this huge report on what has already been done with our optic program and this would not be able to be included until a revision so it’s been pushed back. I’m on vacation this week so maybe I’ll take a bit of that time and reach out.
In other news... There’s one sole Duracell still alive at 243 days. (Two thirds of a year). The other two that were still going died at 218 and 233 days. I used four of the optics to test two Panasonic and two Renata 2032 batteries. They have been installed for nine days so no interesting news there yet.
The last Duracell is still alive at 298 days. The Renata batteries are at 64 days. One of the Renatas is as dim as the Duracell and one is brighter. I’m impressed with the Renatas so far and the Duracell soldiers on…