Hybrid battery condition

There is no "formal" check you can do on the battery. The main indicator of battery health is how fast its charging/discharging or if you have DTC's (ie: Check engine, Triangle with ! etc). If it goes from low charge to high charge quickly this is a good indicator of a failing battery. This is harder to discern on a Gen I so, the real test is mpg's. You should consistently get 35+ Mpg's w/ the AC on in normal driving or 40+ w/out AC.

Here is some good reading for you to learn more about your car.

The Five Stages of Prius Hybrid Operation | PriusChat

 

I noticed people posting mpg ratings but not indicating the speed driven. If I do highway miles at 73-75 mph, I get 45 mpg. City driving (45mph or less) I am getting 58-60 mpg. With the heat now and all city driving with ac on, I am around 53 mpg. My car has over 225,000 miles on it and the previous owner replaced the bad cells at 223,000 miles. I just replaced the aux. battery last month and it was still the original battery! 2001 and runs great yet over 225K!
What are people getting for milage at what speeds driven? Sorry for having this under your post.

 

If you get any of the following OBD monitors, you can test it yourself:

• Scangauge II ($110-150, you enter XGAUGES) - you can monitor or view four different data fields and cycle through about 30. No data recording, it can give you metrics including traction battery voltage, the four temperature probes, the 19 module pairs, the lowest and highest voltage pair, and other metrics. But you have to program in the XGAUGES.
• AutoEnginuity ($500 your laptop) - this is a full diagnostic system that is plug-ready for the Prius
• TechStream-Lite ($1,500 your laptop) - same as above from Toyota

Bob Wilson

 

I believe the dealer can read all the cell voltages with their scan tool and even perform "balancing" which might not be a good idea as it appears to just charge all the cells up to 100%... But I think they charge $100 just to scan the PIDs for the batteries.

 

Thanks,

I had thought about mentioning a 'one time' service call. But even Toyota service departments have mixed skills in doing special requests . . . and I've been disappointed in the past. It is entirely possible asking for this at a local Toyota service department might work but if it didn't equal the cost of a Scangauge, one risks paying for a useless report.

If we are discussing a service or diagnostic call, I would also include the credible, independent shops. They are few and far between but they chose to support Prius:

• Art's Automotive
• Lucious Garage
• AutoBeYours
• Re-Involt

We can help folks learn how to use the tools cited to answer questions not only about the battery but other areas of the car. We can enable them, give them the keys to kingdom of knowledge, so they not only measure their battery this year but any year in the future and there are other failure modes that a Scangauge II can handle. Still, the Toyota service department and independent shops should be considered.

Bob Wilson