lithium batteries

A 12V 180 amp hour LFP with BMS/monitoring system etc cost $1500 a year ago. Cost has probably gone down since then. This weighs about 65 #. We have four in series and run the 13,500 BTU a/c with solar for up to 4 hours . Got back to rig this afternoon and it was 92 inside and overcast with trees blocking sun (not much solar). Ran the a/c off LFP for 30 minutes and dropped temp to 82)