Newbie here. I've never boon-docked before, and was wondering how long I can have the lights on in my TT before the battery gets to a critical level (from what I've read below half way charged is bad...
The answer is a battery monitor that displays the per cent of full charge. With that in place you always know your state of charge and will soon know what you can use. X2 on LED lights - cuts energy use by a factor of 5 to 7. Ebay bargain battery monitor
If you need more electric energy go for a solar panel; nice and quiet for Walmart and any campsite.