Works perfectly!
I bought one of these for my 2023 Harley-Davidson Sportster S. Due to where the battery is located on these bikes, accessing the Re-Start button on top of the battery after it's installed is difficult. When the bike isn't powered on, the charging plug under the seat is connected to the battery. (It's disconnected from the battery when the bike is on) So installing a 9V battery, plugging it in, and flipping the switch "on" for a second immediately wakes up the battery without any drama. Just make sure you turn the switch back off and then unplug it. If you leave it on for more than 10 seconds, it will put the battery into storage/sleep mode.