I've been having an intermittent problem for several months and am trying to determine if it could be caused by anything other than the hybrid battery. When I leave the car int he evening, the MFD shows four-five bars for the hybrid battery In the morning, this will either drop to one bar immediately, or within several minutes after driving. In the latter case, I will get the red triangle warning. If I pull tot he side of the road and wait about five minutes to restart the car, no warning go off and the car returns to four-five bars Sometimes when driving, I'll get the Brake Light, ABS Light, Check Engine & Traction Control Lights at once. Again, these will go off once I stop and restart the car. I've run OBD codes and do not get any codes or warnings for the hybrid battery - only a poor engine performance code. The Prius has not had any hybrid battery battery work done before - close to 193k miles. Brake actuator replaced in 2020.
You need a Prius aware scanner. there’s a thread here for that. your battery needs to be replaced’ or if you’re lucky, it’s just corrosion inside the case. is the cooling fan clean and running?
Generally, if you have warning lights being displayed, you'll have related OBD2 codes stored in the ECUs (computers), find a better scanner? Always best to let the vehicle warm up before moving; on a cold start up it shouldn't take but a minute or two and the engine will turn off. You might try using a "grid charger" on the existing HV battery, either a simple "top balance", or a "reconditioning" by cycling it a few times. Have you tried going step by step through the workup for that poor engine performance code? Here is the step by step work up for DTC P3190 : https://attachments.priuschat.com/attachment-files/2019/10/176519_DTC_P3190_P3191_P3193.pdf FYI : you're moderated until you've posted 5 times.
Try Dr Prius app? Works well with the Carista bluetooth OBD adapter. Just the static test will give you some idea how the internal cells are, their levels, and how balanced they are.
Sure. Several things. Corrosion on the battery bus bars and a bad connection somewhere in the HV system maybe. BUT.....before you spend a lot of time and money chasing ghosts........ Check your 12 V battery and it's connections; the main cables at BOTH ends. If it is over 5 years old, just replace it. How many minutes a day do you guess that the car normally is in use ?