Replaced the Battery!

Here's what I did-tested for phantom drain with no drain found, fully charged and load tested battery with no bad results. Then the weather changed and it became consistent. My last voltage tests showed the battery at 14.5Vdc at rest. It dropped to less than 6Vdc during an attempted start and would return to 12.4Vdc after and just fell lower and lower as I tried to turn it over to see the voltage reading. The blower motor and headlights each drop the running voltage by about 1.5Vdc each. Let's see how this holds up, I will keep you updated. Thank you for all the advice, this is genuinely the best technical forum for our cars that I have found
Cheers