Got our NTU pup a couple weeks ago. We've been in and out to get familiar with it but haven't taken any trips. I noticed a beep coming from the trailer in the driveway the other day and turns out it was the CO/propane detector with a low voltage warning. I looked it over and it's hard wired into the camper, with no noticeable user-serviceable backup battery. So I had to guess it was a low camper 12v battery... I also noticed that the radio head unit screen is always lit up. I flipped all the breakers off at the load center and it stayed lit up. Is the radio hard wired to the battery? Would this be draining it? We brought the camper home with a 7-pin to 4-pin adapter, so I'm not sure when was the last time the battery was charged... But it's odd to me that it would have gone flat in my driveway after a week or two. How frequently do I have to charge the battery? Is the CO sensor or radio a significant drain in the battery? Should these be always-on? Thanks for any tips.