If discharged too much a trickle may not work. If you have higher amp battery charger use that. Then have battery load tested at auto parts store once fully charged. They can't go that long without being on a maintainer.
I plugged the tender in for now, car is in a trailer till my man cave is finished and it’s way behind schedule. I’ll let this go all day and see what happens. Can’t hurt I guess. If just battery, not much to worry about anyway. I was afraid the starter or something.