Newbie here. I have a 2002 Gen 1 that popped the red triangle of death 50 miles after I bought it. Using the Mr. Prius app, I see that the voltage difference is 0.37v and delta SOC is 43%. I have read that anything above 0.3v difference or delta SOC above 20% will trigger this warning. Does this sound correct? Are there any other things that will trigger this warning? The car is still running and the battery still seems to still be working. Is there a threshold that above/below which will cause the car or battery to shut down? Thank you for your help in advance.
Apparently seller cheated you, most likely just before you seen the car he erased all errors, if battery is not in critical condition it need some time to error reappear. Consider return the car as you need new traction battery and this is defect that seller hid from you.
Yes, broadly any trouble code detected by the car's HV ECU, so roughly a couple hundred possibilities. Some have to do with the battery and many do not. The normal next step after seeing the triangle warning is to read the trouble codes to see what the car wants to tell you about. Then, based on the codes, next steps are chosen. Because of Gen 1's very weird networking setup, many scan tools won't see codes in the HV ECU. Toyota Techstream can, of course. If I remember right, some enthusiasts (likely vincent1449p) worked out ways to make a ScanGauge II retrieve Gen 1 HV ECU codes.
Not a threshold, but if there's a large enough voltage difference between banks, this will cause excess heat. If the fan can't keep the pack cool enough the car eventually gives up on the battery and goes into limp mode, where the gas engine revs constantly to generate the voltage that is no longer coming from the battery.