I haven't been in the industry for a little bit, so I'm sure the tech has evolved, but the versions we evaluated used battery hot-swapping to extend use time. I honestly don't recall how long a single battery ran for. We primarily evaluated them for use for loads that were too light or unwieldy to necessitate a vehicle but which were too heavy for a human worker to regularly lift without risk of injury (so the 75-200lb range)

So it needs power to move the weight of the human, plus 75-200lb? I’m wondering if an exoskeleton that’s only for moving a person about might have a lower power requirement or longer battery life?

The human bears their own weight, so they need to move the exoskeleton + load. These systems are more like braces you stand in with strong frames and motors to augment your natural lifting motions than "waldo"-style full exoskeletons. In that respect they differ from what would be needed to help a fully disabled person stand.

Might there be merit to a semi-tethered approach? Enough onboard batteries to last a minute or two when you walk to another room, where you promptly plug in again?

Semi-tethered approach would probably be good for being able to use around the house. And I think this would be consistent with other medical equipment. Some people who require oxygen often have a very large oxygen machine at home with a long cord so they can move around the house, but have to carry portable machines when they are not home.

The portable exoskeleton is a pretty big leap though. I think in order to have it be useful anywhere else but at home it would need to be significantly longer on the order of hours. I'm thinking time it takes from getting out of a car to go in to a shop and run an errand and come back (perhaps extra battery packs in the car or a place to recharge from the car)

Or for added convenience, what if you had something like a roomba that followed you around the house and plugged in to a socket in the room on one end and to the exoskeleton frame on the other end without any manual intervention on your part?

That would be pretty cool. Also made me think of an idea (albient a super unsafe one) of having overhead power to connect to like an electric trolley.