The standard battery bank on the Airstream consists of two 12-volt group 24 batteries connected in parallel stored just in front of the trailer and behind the propane tanks. Group 24 batteries are designed to hold around 75 amp hours of power each. At a full charge, they store just enough juice for you to run all the lights in the Airstream for about 2 seconds. OK, maybe that is a slight exaggeration, but the power-hungry halogen bulbs Jackson Center, Ohio installed into our 25 foot International are not really designed with boondockers in mind. Bright and warm as they might be, they are very inefficient. Many people have swapped them out for expensive LED versions of these lights bought from Internet sources. The problem with this ‘upgrade’ is that in return of them running forever, you have to deal with these dim little blue lights that makes you feel like you are living in the International Space Station.