I had a long trip away from home and left my 2014 Model S 85 hooked up to my charger for 10 weeks while away. I set the charging capacity to 50% to keep the main battery healthy. I also hooked up a battery conditioner to the 12V battery to avoid it being drained. On my return yesterday, the battery conditioner on the 12V battery showed it to be in good condition - all green lights. However, when I started the car I had the "Replace 12V battery soon" message on the dash (the battery conditioner had been disconnected prior to car start). The message remains on the screen after a short (3 miles) trip and is still showing. Has anyone had a similar situation? I'm sure if I take the car to the SC, they'll just replace the 12V battery but why would this be necessary if the battery conditioner shows it to be in good shape? The battery conditioner is a top quality conditioner and quite new.