Hoping somebody can give me some common sense guidance. I have had a gen 2 Prius since 2016 and it had a rebuilt traction battery. Never had to deal with any issues that were battery related. I picked up a 2007 4-5 months ago with the hopes of making some needed fixes and maybe making that my full time car. It has 192K miles and appears to be in good condition. I fixed the issue with the missing converter and O2 sensor and really haven't had it on the road much. The first time I drove it the battery display showed purple bars and it wasn't obvious that it was being charged... eventually it acted what I would consider normal. The next few drives seemed normal, but they were short. MPG was good. high 40s. I had plans to start working on a few things in a week or so and I thought I would give it a good run around. It had been sitting for probably 3 or 4 weeks. It started fine (surprisingly no 12v issues). When I started driving the engine seemed to be running faster than I would expect. I checked the battery on the display and it had one purple bar. The motor ran for my entire trip (5 miles) and didn't shut down even with the battery at all but 1 green bar. Finally when I was about to stop the engine powered down. On my way home shortly after the Red Triangle Appeared. The battery was down to 1 purple bar... Since I was only 5 miles away I decided to keep going. It charged up to the green zone and shut off from time to time. Red triangle stayed on as well as the brakes, VSA and check engine light. I checked the codes and had a P0037 and P0a80. I have Torque pro at my disposal, so I can get the battery voltages.. not sure about battery temp. Thanks for reading this far. Any suggestions how to proceed would be appreciated.
When red triangle goes on it goes into limp mode and mostly only engine... Clear the red triangle and keep going. Dr. Prius app give you battery temps and voltage difference, which are most important data points. You can go a long time clearing the red triangle, as long as batter doesn't overheat. As for repair, replacement battery modules are $35 each and sometime you only need just one... Alternatively, buying a rebuilt pack is good for 3 months to 3 years depending on quality of equipment rebuilder has. Or new OEM is $2500 or if you want to upgrade in similar price try this: https://projectlithium.com/?ref=9qLPw
I will look into dr Prius app. Does it communicate with OBDII/bluetooth and run on Android? I have tech stream but have never gotten a pic to install it on could the issue be purely temperature and related to the fan or fan speed? It was a cool day outside
I had a red triangle in my other Prius for the inverter pump failing. It was able to continue at highway speeds about 20 minutes to a dealer This car didn’t seem to have any drivability issues with the triangle on
Yeah I think it depends on how serious I guess the code is The inverter pump sets the red triangle but then there's another temperature sensor somewhere in there I think it's inside the inverter that tells when the inverter gets above a certain temperature and I guess it can throttle back what the inverters doing like not making so much power not getting so hot
That sensor I believe is the downstream sensor. It is new and denso. I had to replace because the original was taken with the stolen converter. Surprisingly the entire sensor was gone. I expected a cut wire, but it was missing from the harness connector under the carpet. Could the remaining harness have been stressed and caused this code? Since replacing the sensor, I did take the car on a number of drives. I have Dr Prius. It seemed to jump all around while driving, but I honestly did not do a lot of research how it works. I expected to see one or several of the battery banks showing a low charge, but although some seemed lower than others, there was not a situation where several stayed low always. When I left the car after a short couple mile drive, I had all but two green bars. Was purple when I started.
75 degrees outside and the battery temps climbed to 112 by the time I got home. Could not hear any fan noise. I doubt the other day the battery was any hotter I cleared the codes before the trip and no codes or red triangle
Looks like there is a cost for Dr Prius to run a test. I didn't see anything remarkable on the normal monitor or at least nothing i could pinpoint as being an issue. Might just be I don't know how to interpret the bouncing voltages or cells that had different AMP readings. I don't mind spending a few $ on the paid version, but I was hoping there would be more than a % capacity reading at the end. Am I looking for something specifically in the steady state? Is that how low cells are identified, by comparing all of them when the motor is off? I need to check that again, but I think they were all very close as I would expect for batteries that are all connected. I also saw another Hybrid app, but I need to investigate if I can install that on my Fire tablet.
112°, that's only a few more degrees in the outside temperature here in North Carolina right now I would say that's not very hot personally I don't know what hot is for the battery I do know this the other week my inverter pump went out and when I got home my inverter fluid along with the inverter or the liquid going through it was 187°. I let it cool replace the inverter pump running fine charging like it's supposed to so I don't think the 187° for the few minutes it was that hurt anything. But I would have no way to know that it seems to be charging fine the blue bars are correct I rarely see the green and unless the air is running sitting still I almost never see the magenta lines of course I do have a three or four month old new battery
Steady-state is not the best method as the only bad modules that will show up, are ones with a dead cell. These typically show a voltage lower by 1.2 volts or more. A more useful metric is gained by monitoring the voltages when either accelerating or decelerating. Bad modules will consistently have the highest voltage when charging (decelerating) and those same modules will then flip to the lowest voltage when discharging (accelerating). Remember though, that the battery ECU monitors pairs of modules it calls blocks.
Specifically you want to watch the VOLTAGE DIFFerence data on Dr Prius. That is the highest block voltage minus the lowest (at any given sample point). A "good" battery pack will usually have the Volt Diff stay under 0.3V. (it can briefly go higher). You need to drive the car hard to check the battery under high charge and discharge currents. There isn't published info, but the higher the voltage difference (above around 0.3V), the shorter amount of time it takes before ecu sets a code. It can take "awhile" at 0.5V, but almost immediately at 1.5V. By the way, a difference of 1.0 to 1.5V is almost always a failed cell in a battery module. Lower or higher readings could be faults with the voltage sense harness on the HV pack or its connector at the battery ecu (corrosion is a not uncommon fault). Posted via the PriusChat mobile app.
No need to pay to do the other tests... Just keep your eye on "voltage diff" number... The worse that number gets, the worse the pack gets.
Thanks for your comments. I am going to pick this up again in a couple weeks when I am around the Prius again. I think the voltage differences that I saw were pretty small, but I would have to verify. Would be nice if Dr Prius would keep track of the max difference as it fluctuates quite a bit. If the battery pack turns out OK, I may look into reconditioning to make it better. Is was definitely acting weird after sitting for a long time.
If you have Dr Prius on an android phone, you can log data as you drive and it will save as a .csv(?) file that you can look at in MS Office (or equivalent). Posted via the PriusChat mobile app.
They changed something in last version and now it is saving as .asc file when upload to google drive. I have to download it, change file extension to csv then can work with it.
I clearly have a battery issue and dr Prius shows that block 6 is the one to quickly discharge and then quickly charge on braking/regeneration. I was recently in a junkyard where I knew there was a 2005 Prius with a traction battery. Was going to pull it and make a deal. In the week since I spoke with them someone had gotten to the battery and took all but the last three modules. I gave the yard 20$ for those. The picker looked like he removed the other modules with a pry bar as the bolts holding the modules from underneath were still attached I may pull my battery and replace block 6 with my found modules. Block 6 is 1.5 v lower than the rest my poor mans fix will include cleaning the modules and connectors for corrosion and fan and moving the modules around to get the centers to the edges. I am going to skip the conditioning and balancing for now
Didn’t try hybrid assistant but will load it up battery is in partial removal. Noticed, like my other 2007, it has a dorman rebuild from 2015
