One last time
Bubblehead,
The control panel is confirming what we have already been telling you. Is is normal to leak freon over a period of 8 years---yes. It can leak from a failure in one of the metal housings in the system, o-ring seals, and the front seal of the compressor.
First of all, at least entertain me by doing the battery thing. If that does not re-energize it, please let us know.
Second, take a long careful visual inspection of the a/c system. Trace all the soft and hard lines. Look at the bottom side of your hood just above the a/c clutch for a build up of oil/dirt. You are looking for any area that has an excessive amount of black oil/dirt build up. Chances are, that is your leak. You may need to reset the computer, degrease all the lines spottless, then drive the car for a few thousand miles. Keep checking the lines. You will see where the leak is without introducing the leak detector to the system.
If you have done all above and can't find a leak, but the system still drops--you may have a leak in the evaporator box in the dash, or the condensor by the radiator. At this point you will need to see a QAULIFIED a/c shop. How do you know they are qualified? I would quiz them about the battery disconnect trick. If they know about that, they might just know another thing or two. They will need to use a leak sniffer to check around the other places for a leak. Once found, it can be replaced/fixed and you are back in business.
I would only introduce the leak detector chemical if all else fails. There is no need to have additional chemicals in the a/c system. The cleaner the better.