Visited yesterday on foot.
The chargers are in level -3a. 5 parking spots are painted with the EV sign.
The layout of the parking confuses me, and only now that I review my pictures I know for certain that there were multiple entrances. I'm not certain whether the 2 parkings are connected or are completely different.
I photographed the older entrance, the one with the sign "Oberdorf Märit" which is directly under the Migros. But there's actually another entrance and exit on Scheidgasse, which wasn't built yet in the street view images of 2014. It's quicker to enter from the Scheidgasse, then you turn right and go down one level and the charger are there. It's probably a labyrinth coming from the other side, if at all possible.
There's a sign "Parkhaus schliesst bei Ladenschluss" above the Migros entrance, but the parking now seems to also serve the restaurant next door and has other foot exits. The parking meters in -2 and -3 read "Parkhaus is ausserhalb der Öffnungszeiten geschlossen!", including at the other foot exit outside of Migros, and the parking meter has tariffs for "Montag-Sonntag 00:00-24:00 h".
I'm not sure what the parking is really called, because the old sign "Oberdorf Märit" already visible in street view 2014 is still there, but inside the parking all signs seem to call it "Bären". If the 2 parkings aren't actually connected then it makes sense to have 2 names. The chargers would be in "Bären" then.