Prius I warning lights

My 2002 Prius had 180,000 miles on it when the 'triangle with ! in middle' came on along with 'PS' and 'check engine'. Car was drivable home. Disconnected battery and all went away. Happened again about 300 miles later. Car was drivable. Again disconnect and reconnect battery. Good for a month around town. Seemed ok to go on vacation. First leg was a 200 mile drive and at about 150 the car died on the freeway and had to pull over. Again disconnect and reconnect battery. Drove for another 10 miles and died again. Again diss/recon battery. Got to destination disconnected battery and car sat overnight. Continued on trip for 700 miles and lost power again. Diss/recon and found hotel where disconnected battery overnight. Next day went 500 miles on to 2nd destination. Car ran fine. Heading back home drove 700 miles heading back with no problems. Next day made it 60 miles and car died again, it was 105 degF. Diss/recon and made it 10 miles where alarms came on but car didn't die. Made it to gas station where diss/recon and continued on. In remote area so no dealer/mechanic around. Made it another 100 miles with 5 diss/recon in between with just alarms coming on until the 12 volt battery finally went dead. Had car towed home and put on charger in drive way. Car has run fine since around town. Have not been able to recreate codes to take it to the dealer without fearing a long drive will kill it. Most of my long drives are through the desert. Waiting for codes to come on near home.
Anybody been through this? Suggestions?