I was going to say the LDG-Z817 uses latching relays, so it saves battery draw versus other tuners that do not use latching relays.
Depending on how you operate your mileage my vary..
I did however set my FT-718 with internal battery pack in my sock drawer after field days, then Christmas even pulled it out to listen to a Santa net with friends in the living room where the fire place was making it nice and cozy.. Had to resort to a wall wart power? because the NICAD pack in the FT-817 would not even turn on the radio.. But the wall-wart saved the evening as the group that was over simply wanted to listen to the Santa Clause net..
Anyone that is anyone in Ham radio spends a lot of time playing with BATTERIES.. Matter of fact.. I can recommend 2 things...
#1. batteryuniversity.com ... The best place to learn and ask questions regarding batteries.
#2. My article on building a Battery Analyzer in MAY QST 2022 page34...
Larry W8LM....
Larry Macionski