Unplug the unit from the 110 power.
Open the cover.
Unplug the battery.
Wait.....
Plug the battery in.
Close cover.
Plug in 110.
I have to do it once a month.
I think it’s on a timer, the battery tests fine.
Amazon has the batterys too.
Tried, very hopefully. Still screech-beeping every 3 minutes; but, Thanks.
(It wouldn’t bother me so much if I hadn’t been suffering a tooth issue, waiting until Monday to see a doc with restricted hours due to Covid, and then perhaps anticipaing oral surgery. And dishwasher died this week, too! I guess when it rains, it pours; and things could be a lot worse :-)