Does anybody know if any cruiselines offer rooms with access to a backup generator?

My grandfather has a heart pump that operates on a battery that requires him to plug in every night. He had me researching Alaska cruises last year before he had the device put in & had to postpone the trip because of the surgery. I am going to research to see if it is possible for them to take the trip this year, but they won't be able to do it unless the ship has a backup generator in case there are issues.