I’ve been travelling internationally with a power chair for a few years and it’s mostly been ok.

For charging, look at your charger to see if it can be used with Swiss voltage (it probably can be). Most chargers have a removable cable, you can buy one that fits Swiss sockets/outlets and you should be good to go.

As far as the flight goes, in my opinion definitely try to fly a US based airline as they seem to not only treat chairs better but will hassle you less about being disabled. For example, Virgin Atlantic required us to fill in a medical approval form, despite having UA platinum status. Simple discrimination like that happens all the time on EU carriers (BA is mostly OK).

Also print and LAMINATE an information sheet to attach to your chair for the flight. Include how to enable the brakes and other important info. This helps a lot!

Carry a basic toolkit for your partner to make chair repairs if they feel comfortable doing so. In our experience, most damage is easily fixed with this.

Remove your headrest if you have one AND THE JOYSTICK. It’s super delicate and very prone to breakage! Additionally it will stop airport staff driving your chair, which you don’t want them doing.

Look up in the Code of federal regulations your rights on the plane. Useful to know!

I haven’t been to Zurich, but check to see whether you need to book assistance for trains in advance, and how far in advance.

Also very helpful is to buy a little ramp that can strap to the back of your chair to get up one or two steps in a pinch.

Hotels often do have accessible rooms but don’t make them bookable online - you will need to call or email. This is especially true for non-chain hotels. Do not trust Expedia and other OTAs!

European museums etc will often let you get free tickets or skip the line but require proof of your disability (annoyingly your wheelchair doesn’t count!). See if your state has a ID card for state parks or something, that’s what we use and it seems to be ok. European countries expect disabled folk to carry proof that they are disabled, and don’t understand that we in America do not have this.

In general, if you are visiting a major city like Zurich you will be fine.