My new Red Optima died when I kept it in the garage for 1 week
What is a good battery jumpstart kit with cables

If that Red Top was in good condition and had a decent amount of charge on it, it should not have gone dead after only a week of storage. It needs to be charged on a battery charger, not jumped, then tested.

This is the second red top that has started to die this way
I had my mechanic test for hidden current drains and there were none

I have an underdrive pulley kit, is this causing the red top to die ?

When I bought my 92 Justy it came with an Optima Red Top...(lol battery worth more than the car)...I stored the car from March - October with the battery cables disconnected. When I brought out the car and reconnected the cables the car started up within two cranks! No BS. I have a new respect for this battery. Perhaps your battery is a lemon.