Backing my V8V out if the garage it stopped dead. The battery cutoff switch had not been touched, but all systoms were down just as if the switch had been set. I used the reset button behind the seat, but nothing happened and everything was still dead. About 45 minutes later the car started fine. What would make the car stop dead like this?

 

Doesn't sound like the battery switch but it does sound like the battery. Are the battery leads tightly secured?

 

I'd check you battery for sure. There a lot of places will test them for free. But the downside is they aren't the easiest batteries to take out. Summer driving /heat and A/C use can put a strain on a older or weak battery? You said you charged your battery.... do you used a battery tender? If not, I would suggest one unless you're Aston is a daily driver.

 

Does the test hav to be done directly on the battery or can it be done from the outlet in the engine compartment?

 

The first thing you need to do is make sure the positive and negative cable are really tight on the battery. Get access to the battery and tighten the cable clamps. If there is any corrosion at all on the posts then you need to take the cables off and clean them. You can test the battery's voltage from the positive post under the hood but you cant do a load test on the battery from there. The battery will have to come out to do that or you will have to take it to a shop that has a portable load tester. It sounds more like a cable problem or possibly a bad ground cable under the car somewhere.