Is there a HV battery test...

There is a test but its not for estimating remaining life. That is impossible. It's for seeing if it's unbalanced, if there are any bad or marginal modules, etc.

 

I got the following information from someone else. There are no tests you could do to predict the remaining life of the battery. However, if you battery was dying, the MPG will start to go down. Also, the battery do not degrade due to the total miles on your ODO. It degrades due to age and extreme heat. Not sure if extreme cold would degrade the battery as well.

 

Where is the test in TechStream?

 

You can see the internal resistance for HV battery cells. It will tell you how the battery is balanced. Usually multicell batteries don't die in one moment. you can either use the Techstream or the Torque Android app with customized PIDs for Prius published on this forum.

 

Perhaps you would like to find it?

For the 'test' to have any utility, someone in Toyota would have to run it. The most likely would be the Toyota technicians who work at the dealership. The first step is to buy the Prius shop manuals for your model and read the diagnostic section. But this assumes the secret 'test' runs in English.

If you are Toyota and want to keep it secret, you would make sure it is not part of TechStream and certainly not in any form that "the public" might learn. It might be written only in Japanese. But from my studies of Prius NiMH batteries, no such 'test' could exist.

Now there are some things you can measure but they do not translate in '% of life' of the traction battery:

• module voltages at different SOC - Techstream can report the 14, module pair voltages. By using forced charge and "R" discharge, you can vary the state of charge between 80-40% and see if any of the modules are starting to wander off.
• traction battery temperatures - less precise, it is definitive when a traction battery is becoming weak, they start to run hotter. Actually this is definitive when a traction battery has started to fail. But they are useful to diagnose operations that are stressing the battery . . . heat is the enemy.

Are you interested in this approach or still after the 'test?'

Bob Wilson

 

Here's some info...

 

OpenElectrons.com has a Traction Battery Health Monitor that plugs in your OBDII port and records HV battery data such as individual battery module pair voltage and resistance, 4 battery temp sensors, SOC, Amps and HV Battery voltage. This is very similar to the report you get from your dealer.

This will not give you a % of remaining life but it does give you current operational data for future comparison as the battery ages.

 

Any way of getting this done honestly at a dealership? Im under warranty still so im betting even uf they did it and battery was going bad they wouldnt tell me....

 

Your dealer can connect the Techstream computer and give you a battery test report which will give you the current operating data. They will typically charge you about $100.

If the battery was having issues it would be triggering DTC's. Unless it triggers a DTC the dealer is not going to do anything under warranty.

 

That device is called a "Can Log" and was out of stock at openelectrons.com when I called on November 9, 2013. But the proprietor said he was having more ordered and that the price would be about $50. You will also have to purchase a 16 gigabyte micro-SD card for it to record data on, which data must then be downloaded to your computer for viewing. I think this information will be invaluable as the traction battery ages and we attempt to keep them balanced and serviceable.

 

Your thinking is incorrect. The Dealer makes money identifying and fixing problems. The Dealer is NOT Toyota. He is a completely separate company. So it's in the Dealers interest to find work to do, warranty or otherwise.

What you actually have to worry about is a dealer "finding" work to do that doesn't actually have to be done! Which is one of the many reasons Toyota gets involved when the Dealer "finds" a major failure.

 

That is good information. I was a Beta Tester for the device and the device came with the micro-SD card. I just needed to purchase a micro-SD card reader.

I totally agree with the value of the recorded data. I record trips 2 to 3 times a year and compare the data against my first baseline trip. I export the data into Excel and then can create trends to evaluate. We should be able to detect a decline in battery health long before an unexpected DTC is triggered.

The best part to me is that you just plug the device in the OBDII port, remove it after your trip and then download to your computer. No external devices to distract you while driving.