Jul 14, 2019 · Other Battery Powered 12 Volt Air Conditioners. Mabru 12,000 rooftop AC; Kingclima RTX 2000 rooftop AC; B-Cool 9000RM rooftop AC; Fresair cooling unit (not a true, compressor-based air conditioner) Portable Units I’ve seen some van conversions that use a portable AC unit like this one. These are fairly inexpensive and generally use less energy