Seeking recommendation for a place where I can rent a folding power Wheelchair in Paris?

Try Bastide, a large medical supply chain all over France. They deliver.

https://www.bastideleconfortmedical.com/bastide-le-confort-medical-paris-6eme.html

Bastide's a good lead, but folding power chairs are a niche item here. French medical suppliers mostly stock manual chairs and standard powerchairs, folding electric ones are less common, so don't assume a shop renting wheelchairs has one, ask for the specific model and confirm folded dimensions and weight before committing. Search "location fauteuil roulant électrique pliant Paris," English searches mostly get you tourism blogs. Also try pharmacies, a lot of them rent medical equipment and people forget that, a big one near your hotel might rent directly or point you to their supplier. And ask your hotel, larger Paris hotels get this request often and usually have someone who delivers to the lobby.

Most of these shops only answer the phone in French, so email works better. Write it in French with DeepL, include your dates, delivery address, your height and weight, and a phone number. Something like: Bonjour, je souhaiterais louer un fauteuil roulant électrique pliant du [date] au [date], livré à [adresse]. Est-ce disponible et quel est le tarif ? Merci.
Ask specifically about delivery and pickup at your hotel, and what happens if something breaks mid rental, that's the answer that matters most on a short trip. Book now, not in September, there won't be a dozen of these sitting on a shelf. And if this is for airport transit too, check the battery type against your airline's rules before you rent, not after. Hope it all comes together smoothly, sounds like a trip worth getting right !