Traction Battery Health Monitor for Toyota Prius

Just got my CanLog and tested it ok. I was surprised by the message on the device "For Testing Only Do not drive with this device connected". I thought I could drive with it plugged in. What's the story?

 

Is the message actually printed on the device? I drive to and from work with mine. Mine was a beta test device and did not have the message.

Logging the HV battery data while driving is what you want to see and not just sitting in your driveway.

It makes me wonder if OpenElectron.com is just playing CYA.

 

It must be (CYA). The User Guide still tells you to connect it to the diagnostic port and it will collect data as you drive the car.
Now I'll check some driving data.

 

Still need more beta testers? I'm an electric engineer and would love to get my hands on one of these.

 

They are now selling them. I bought mine foe $49.76 plus $6.56 shipping. It collects battery and motor generator data while driving. Working fine so far.

 

Link?

 

OpenElectron.com

 

Interpretation of results please? Just got it and finally figured out how to use it and graph it through google spreadsheets.

Could you take a look at these and let me know your own opinion of the battery health and clear up a few questions?

This is done on a cold car, started then driven around a couple of blocks and then parked.


The seconds displayed in my txt file, are they generally accurate? Mine started at 22 and ended at 239 for this quick trip. Seems the gap between readings is generally between 2-10 seconds as per the user guide but otherwise random....I am guessing this is normal?



The brief instructions say generally the normal NiMh cell voltage should be 14000mV-1800mV
What say you that dip to 13000?






Why are there no values for Rb1 and Rb2 in my initial data file to put on this chart?






What IS MG? Is this torque or temp?? I wasn't sure if these were the temp readings so put temp on the vertical axis. If this is torque, is this in percentage of available torque to a max value of 100% or something else?






What is Tin and T1 and T2?
Maybe these are temps, or are these torques? It makes sense that these may be temps since they continue to rise except for T_in which oddly drops?

 

Looks OK at this scale. To be sure you can plot the difference between each module and the average V (at each moment) and see if there is any module that stands out too far away from the population.

This is a question for the manufacturer of the device.

MG is short for Motor-Generator. There are 2 MGs in Prius. The slowly varying values are the MG Ts. The spiky ones are the Ts of the inverter circuits that drive the MGs.

Tin may be the intake air T for the HV battery. T1~3 looks like the HV battery Ts.

 

Here's some interesting battery voltage data from this morning's drive to work. 33 minutes, slowly moving traffic but not a lot of stop and go.

Here's the battery voltage for all cells with a constrained range to more clearly see any variances:



There is not a lot of variance but some.... I'm not sure at what percentage difference you can consider an individual cell to be a problem.

Curious to see what an actual difference would look like, I skewed all the values in one cell down by 2% and graphed it again:



The cell that is down 2% on voltage stands out a surprising amount. Shouldn't have any problems spotting an iffy cell with this device.

 

Ok......what is the parameter SOC? and what units?

 

Moved to main forum where it belongs:

Traction Battery Monitor results and information interpreted. | PriusChat

 

SOC = state of charge, presumably in percent, and should vary somewhere between 20 and 80 or so