Does anyone know where I can find information on building a device that would prevent my battery from running down if I accidentally leave my interior lights on? Ive seen small devices for sale for $70 or more but that seems pretty expensive for such a simple gadgit.
I just replaced my dome light "festoon bulb" with a multi-LED unit (you can get pre-made drop-ins if you don't want to solder one up). Now, my battery will still be fine even if the light is left on overnight.