Great information and I will certainly check this out. I tend to not drive my 996 frequently enough to keep the battery charged, and one time found myself in a place where I could not reach the battery under the front hood. When I had last driven the car, I armed the alarm and locked the door with the key fob. When this happens, the not only is the alarm set and the doors locked, but the front hood is locked as well.
The battery drained to empty to the point I manually unlocked the car and was able to enter the vehicle, but the manual front trunk release was engaged by virtue of arming the alarm. So I had a bit of a conundrum - couldn't get to the battery because the hood was locked and couldn't unlock the hood because the battery was dead. I learned that removing the front left tire and wheel shroud I would be able to access the manual release cable, but do not have jacks or other ways to get take off the front wheel.
DC trickle chargers through the cigarette lighter seemed to be a good idea for maintaining a charged battery (e.g. battery tender for storage) and obviously wouldn't try to jump start with a CLA battery tender. Checking with my local dealer though, I used a Porsche-branded trickle charger (yes, I overpaid for the label on the front, but I wanted something I knew would work) and after leaving it hooked up for about four days, enough charge existed to start the car. I was actually a bit surprised it worked, but with patience, the battery got to a state of charge that allowed it to start.
Hopefully this will help someone else that finds themselves in the same situation.