Many older Airstreams had the battery in a back compartment as they came from the factory.
There are two things to consider:
1. The weight of the battery in the back. Don't overdo it, as many Airstream frames are not really good with a lot of additional rear weight, such as bicycles and so on. If you have a 4" frame on your 24' it may be marginal as to additional rear weight capacity.
2. The 12 volt
charge capacity while towing will be reduced because of the long run of the wire from the TV engine to the rear mounted battery. You probably should expect only 3 or 4 amps in that situation.