I'm using the Porsche brand battery maintainer for the 3rd year but this is the first year the car has been close by and I could check on it periodically. Should the red light be on at all times or only when actually charging?
Only when charging. If you want a quick check to make sure it's working properly, open the door - which turns on the interior lights and dash - then look for the red light to come on.
Current Love: 2008 RS60; 1st Love: 2001 base, triple black