I have a 488 spider for about a month now. Only has 300 miles and I’ve only driven it roughly 7 times Went to start it today and it didn’t. I connected the tender and after an hr on, I tested it and it started. About 6 hrs later I checked and the tender was full “7” . Just to check, I unplugged the tender and started the car and shut it off after a minute and then plugged the tender in again. It showed “3” and about 15 minutes later went to “4” Is this normal or does that mean the battery isn’t taking the charge? I’m getting different answers from other owners.