Fully charged my battery on Thursday night and the car was not used on Friday. On Saturday, I noticed the battery is empty again which means the batter lost all charge in less than 48 hours. Is this normal?
Not normal. Could be a bad battery or something is putting an unwanted drain(parasitic) on the battery.
If the car's in READY mode, it will keep the traction battery at least viable in the HV portion of the SOC. No way it would run all the way down.
Welcome. You didn't give us a lot to go on there. Several questions come to my mind to help figure out what happened since those batteries don't self discharge like that. And one comment. The comment is that it's wise to pay attention to the owner's manual when it says that it's not good for the battery to leave it fully charged for long periods. If you want it to last as long as possible, charge it right before you use it. Questions. Have you had the car for a while and are you familiar with the charging scheduler? Are you absolutely certain it actually did charge? When you plugged the EVSE into the car's charging port, did the green light in the port blink several times and then go out or did it just come on and stay on. The former indicates that it's going to wait till the next scheduled charge while the latter says it's charing immediately. I ask because until you get familiar with the system, it's super easy to assume that it will charge but then it doesn't because of some oversight in the scheduling or other assumption.
