Hi. We are new to camping without a tent. We don't need much in our pop up camper, and were ecstatic just to have some lights at night. We need to buy a new battery and my husband tends to go overboard when researching and always thinks we need "the best". Sometimes, less is more. We are changing out our two interior bulbs with LEDs that use 160 MA. We have a propane detector that draws 70MA. By our calculations, using the lights for 3 hours a day plus the detector, we would be using about 3 amps/day. If we get a battery with approximately 100 amp hours and plan to only use 50% of that, that gives us 50 amp hours. Using only 3 per day, 50 divided by 3 amps is around 16 days. After doing a lot of reading online, this sounds ridiculous. I am mostly readin that people can boondock for 4 days with minimal usage. What am I missing? We will be doing almost all of our camping on battery, and we are trying to decide what we really need and what would be overkill. We think we might be able to squeeze in a 27 group battery, but only have a 24 box. Thank you!