My screamer is switched to the ignition, but my radar detector is hardwired to the battery. I knew I'd eventually kill the battery by forgetting to turn off the Escort, and I finally did.
In unrelated news, I finally bought a battery tender at this yr's mc show, and that's where the 2 stories collide. Upon hookup, the tender blinked red. The RTFM said the blinking red was possibly because the battery was at < 3.0V. (There's a circuit setting that prevents the tender from functioning on a battery that sits below 3.0V.)
So, I fired up my battery charger, brought the battery back from the dead to about half-way, and of course the Deltran Jr tender now works.
All respondents to the following question are requested to keep in mind that my Gr 12 physics class was 23 years ago: why does the Deltran tender Jr not charge (by design) batteries that are at less that 3v, but will charge batteries that have been charged passed 3V?