Good to know. I will probably go with the ones you sent the photo of. For relatively small use, I assume that I can get away with one battery?
One of the good batteries is adequate. When a battery is getting low a motor will miss occasionally. As time goes on the miss happens more often. You have quite a bit of time before the motor will barely run and then comes to a stop. You will need to have a batt. connected to check for spark.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.