Trianlge help it was 95 degrees today

I parked my 2002 prius with 133k miles in the parking lot today from about 6 hours in the direct sun at 95 degrees. I came out and drove away. All was well for 3 minutes then the triangle warning light came on, the touch screen had a trangle, the letters PS, and a picture of a car with either a ? or a !. I finished driving about 5 miles and it drove just fine, same mileage. Parked it for 30 minutes came out and the triangle was gone. Drove it for 15 minutes parked it in the same hot parking lot, left the windows open this time. An hour later I drove about 45 minutes and again no triangle. It drove fine the entire time. What should I do to test the battery? What is this I have heard about rebuilding with gen 2 cells?

 

Well I did check the pump and the fluid is moving and full and clean, but I can't hear the pump at all, supposedly that is good. My car is scheduled for the steering recall in a few days as well as a CPS recall. The 1st dealer I called wanted to give me a discounted rental while they worked on my car. I told them no since why should I pay for replacement transportation while they fixed a recall due to manufacturer error. The next dealer offered a courtesy rental for free and verified that they had the kit and parts in stock. The next dealer also had more certifications then the 1st according to toyota.com. The first dealer also said they had never done the recall before where the next dealer knew what I was talking about. Will they need to do an alignment after the steering recall. Anyway I went ahead and removed the traction battery and load tested each cell and found 2 bad ones. They had higher voltage than the rest but the amperage was low. The rest of the batteries where almost identical in voltage. I just upgraded to the newer cells as suggested. Problem solved, and it seams to be getting better mileage then it ever did before. None of the old batteries appeared to have leaked but there was a glue on all of them that the newer batteries didn't have. I used the some of the old cells to convert my corded lawnmower into a cordless rechargeable unit. The cover on the lawnmower still fits just fine too. Its just heavier now.

 

Oh in addition I hooked up my scanner and didn't get any codes. It just said no codes. Maybe my scanner is too old? its and OBD2 scanner I bought for $150 4 years ago and autozone sells it for $80 now. It wouldn't read codes from a friends 2008 trailblazer although it would plug in and power up but never could talk to the trailblazers computer.