I started the car two days ago while still on jacks.....it ran fine.....

…yesterday after I buttoned it all up, it would not start. The battery turns over the motor once and nothing.
Lights turn on in dash, outside and in trunk but no start. I tried jumping the car but nothing.
Could the battery have died in a couple of days?
Do I have another issue?
Can I VAG-COM the battery with its low power?
Thanks in advance.