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Discussion in 'Gen 2 Prius Technical Discussion' started by S Keith, Mar 14, 2016.
7/3/2003... I guess they don't make 'em like that anymore...
Here is another test, temp was 72 degrees after 24 days after grid charge / discharge.
Test pulled the expected current. Goodness.
View attachment 111059
Still great results given the mileage/age.
Most of your operation is still in the shallow sloped portion of the SoC curve, and your overall capacity is substantially higher than before.
DeltaV remains very near the 0.2V mark.
A couple questions...
1) was the car cold? Your battery temps seem high for a 70s day.
2) Did you reset the 12V before testing?
We had driven the car maybe 20 or so mins before the test. I did not reset the 12 volt before test, did disconnect the 12 volt when I took pictures of the cells sunday. Would have to look at what mileage is now, estimated about 1600-1700 miles since I did the grid charge.
It's not that big of a deal, but it makes the test more consistent for comparison purposes.
Your individual blocks are spread across the range:
View attachment 111069
While blocks 4, 7 and 8 are your weakest, they are still trading spots in the MinV position near the end of the test.
All data suggests that your pack has deteriorated uniformly over its lifetime. The initial results are likely artificially high as I would expect 1-2% deterioration per year as is typical.
Note that while SoC accelerates its drop off near the end, look how the voltages do not. This suggests to me that the SoC drop-off is due to the car's SoC computation iterations over time.
Whatever the case, I would absolutely call this a success. I recommend you continue driving normally and re-test at the 90 day mark. Until then, keep an eye on your SoC gauge. If you start to notice significantly more activity that you can't attribute to driving conditions or A/C use, run the test earlier.
I'd love to revive this thread from the dead! I had force charged/discharged mine the other day to try to determine battery health but couldn't find results to compare with. I just got a Torque Pro, can you explain to me exactly what to track/log? I currently have a display that shows the voltages of all 14 blocks. Should I include other information to log such as SOC, battery temps, etc? I'd love to do this and see where I'm at. We just purchased the car last month and I've never had a Prius to compare it too. It's a 09 with 110k miles.
The 14 module pair voltages are one measure. Look for any module pair that discharges to lower voltages than the others. A 0.3 volt difference will be flagged by the battery ECU as a problem.
The other indicator is the effective series resistance of the module pairs. They should all be the same as any that differ from the others will display a different terminal voltage under heavy load or heavy regenerative braking. Again a 0.3 volt difference gets flagged.
The sooner you start a grid charging maintenance routine the better.
FYI, skeith hasn't logged in in over a year. IIRC, there was a "dust up" with others and he left. Or was that strawbrad? Or both?
A .3 difference? So if the 14 blocks are mostly at 17.1 - 17.2 but say one block is at 17.3 and one block at 17.0...this would cause a cel for the 17.0 block?
Yes, but the feared code "PA080" is triggered when one module of a pair has a failed, shorted cell (1.2 volts lower) which happens if a cell is fully discharged and a reverse voltage is applied (trying to discharge it further). That is why maintaining a fully balanced battery pack is important if you want a long HV battery life.
Hi StephenJ, will you run this test? I just got Torque Pro + ODBII and it's really cool getting all the data. I can't make sense of it yet. I also got a Google Drive plug-in called Torque Log Analyzer. I ran that analyzer and my deltaV looks good but I guess Steve here is saying deltaV is not that meaningful so I'm going to try his procedure and see what that tells me.
My primary problem seems to be that the ICE comes on more than it used to, and I'm trying to figure out why.
Hi Peter, I was just looking at this link you gave in the other thread Torque Log Analyzer: hv
That looks great, I'm going to get that set up. I also just got Torque Pro and am still figuring it out. On the page of that plugin there is a link to a custom PID. Do you know if this plugin will work with the PID I got from here on Priuschat? I'm using the one in this thread... Gen2 Prius: Custom PIDs for Torque (Android App) with formulas | PriusChat
Yep that's the PID I'm using!
XT1635-02 using PriusChat mobile app
Can this test be applied to Toyota Camry, and Highlanders as well? @S Keith
S Keith. Can this tests be conducted in a tropical climate like Nigeria?
Temperatures sometimes range from 30-38°C?
What necessary precautions should be taken?
Steve Keith is no longer active on Prius Chat, so you will not get any reply to your questions.
To answer you questions somewhat, the concern was cooler temperatures, where the A/C would not draw a high enough current to make the this usable. As long as you get around 15 A consistently for the duration of the discharge, the test will give you usable data.
OMG! Thanks for the replay though.
PS: The 15A, you're talking about, can be read on the tech stream, or what?
Yes, when you run the test monitor the HV battery current.
I wonder if the discharge of this test can be done by pulling current from a 12V battery using light bulbs or something like that instead of running A/C, defroster, etc. Seems like it would be a more consistent way of pulling known current (using a known load like light bulbs).
Great thread! I have a HA reconditioning kit ordered and waiting its arrival. I opted for a smart discharger. My car is an '07 with 179K miles. Getting upper 40's mpg in mixed highway/rural road driving. Closer to low 50's when highway is not part of the mix. I think the battery is fairly healthy, but I do see a lot of SOC display action from Green to Blue, but I only saw purple once and I don't remember the circumstances. I really want to keep this battery chugging, hence the HA purchase. I will perform a before and after test, but would like to see if there is a better, more consistent way of discharging during the test.
You should purchase a brand new battery from Toyota instead of buying that kit. Your car is 10 years old and so are the modules. You will not get another 10 years out of them with the HA reconditioning kit. The Gen 2 Prius often makes it to 400K miles. So even though a new pack is more expensive it is a far better investment because if your car breaks down or gets hit you can always sell the modules afterward and get some of your money back.