Visited on April 3rd and charged without any issue.
The chargers are in the underground parking. It's not a big parking, so it's easy to find the chargers. There's an M-CHARGE sign at the entrance but at this point you have no choice but turn right anyway. Then you see the chargers 2 turns later.
There are no gates, it's a parking meter. 2h free.
It's a 6-spot setup like in Delémont, with an obvious way to add 2 more spots in the "empty" quarter.
There's some additional space between the parking space and the wall on one side. Perfect spot if you don't know how to park!