2015 Fusion Energi
MAIN battery was fully charged.
Due to COVID-19, didn't drive the car for over a month. Went to drive it, the car was dead, no power at all. So I jumped the TRADITIONAL battery from our other car, got everything working again. Drove the car just a little bit, using main battery power only. Got main battery down to about 80%, and when I plugged it in that night it wouldn't recharge. So today I drove it so that the main battery was completely discharged, and plugged it in again. Have tried both power cords that I have. Both are receiving power from the outlet, and both display that they are relaying the charge to the car. However, while the light up quadrants around the car's charging plug in port do their usual flashing sequence, and the first quadrant starts the slow flashing indicating it's beginning to take a charge (and I hear the main battery start to hum like usual), after just a few seconds the light up quadrant goes dark and the battery goes quiet.
Did something about running down the traditional battery ruin the main battery's capability to take a charge? Anyone else dealt with this before?
Thanks in advance.