How do you test traction battery in used gen 2?

If the battery is busted you would see the red triangle. All of us would love some simple way to estimate remaing battery life or predict impending battery failure. Your best bet is to look at millage and how the car has been used. Flat and cold are better than hilly and hot. Thruway is easier than city.

If you have Torque you want to get extended codes here. Gen2 Prius: Custom PIDs for Torque (Android App) with formulas | PriusChat

You could check impedance and voltage of each block. These should all be the same, then again you would have red triangle if they were not. Another check is the reverse stall test, but I don't know if I would do this on a test drive. See here Traction Battery Testing Questions... | PriusChat

If your kids can wait buy a 2015 for yourself and give them your gen 3.

 

In my opinion, it should be the kids looking to buy a new car if it was their fault.

You can check the voltages of the modules to see if the pack is currently good, but there's really no way to know for sure how much longer a pack will last. Do a test drive that puts the battery through its paces, as well. Extended EV driving, accelerating up hills, the performance should be almost as good as your Gen3.

 

If you have the mini VCI, then you can look at all the block voltages and internal resistances, which are accessed through the Battery ECU. Do this as passenger during a test drive. It will even graph some parameters over time. You should see only small variations in the individual modules. Any outliers are an indication of impending trouble.

As mentioned, any predictions are not possible based on the above data. Used Prii are just going to need a new HV battery sooner or later.

 

With some effort you can configure Torque to log the properties of the HV battery. The HV battery is broken into 14 "banks". The idea is you log the average voltage of the 14 banks as well as the difference between the average and each bank. I log every 5 seconds.

It is important that the math is done in the torque custom PID formulas. If you log the raw data and try to calculate later, you will find some time elapses between the data samples which causes the data to be off.

I believe if this difference (delta) is greater than 2 volts, it will trigger the CEL and you dealer will tell you a battery replacement is required.

So, you start up torque and turn on the logging. Then you go for a test drive. You want to drive it for a while (20 or 30 minutes couldn't hurt). You want to have times where you run the batter nearly out (like turn the AC on max cold while in park) and times where you charge the battery to full (like lots of regen going down a big hill or holding your foot on the break and also pressing the gas). You want to end up with a wide variety of conditions (slow charge, slow discharge, fast charge and fast discharge).

Now you have the data, what do you do with it? Use a program like Excel or Mathmatica to create 14 histogram graphics of voltage delta. When you look at the 14 charts, they should appear to be fairly similar. If you have one that has lots of outlying data points, it's a suspect for failing first.

This won't tell you when the HV battery is going to fail, but it will help you determine if something suspicious is going on. This technique is really better suited for a Prius owner who does this every 6 months to see when the graphs start looking abnormal.

I should really be doing the same charts for battery block resistance, but I haven't got there yet. It should be the same process using different source values.

Let me know if you have any questions; I'd be happy to help.

Here are my Torque custom PID's:

Code:

"Name","ShortName","ModeAndPID","Equation","Min Value","Max Value","Units","Header"
"HV Battery Block-01 Delta V","HV Delta BK1","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * D)  + (0.01 * E)  - 327.68)","0","3","Volt","7E3"
"HV Battery Block-02 Delta V","HV Delta BK2","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * F) + (0.01 * G) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-03 Delta V","HV Delta BK3","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * H) + (0.01 * I) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-04 Delta V","HV Delta BK4","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * J) + (0.01 * K) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-05 Delta V","HV Delta BK5","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * L) + (0.01 * M) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-06 Delta V","HV Delta BK6","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * N) + (0.01 * O) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-07 Delta V","HV Delta BK7","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * P) + (0.01 * Q) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-08 Delta V","HV Delta BK8","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * R) + (0.01 * S) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-09 Delta V","HV Delta BK9","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * T) + (0.01 * U) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-10 Delta V","HV Delta BK10","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * V) + (0.01 * W) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-11 Delta V","HV Delta BK11","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * X) + (0.01 * Y) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-12 Delta V","HV Delta BK12","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * Z) + (0.01 * AA) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-13 Delta V","HV Delta BK13","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * AB) + (0.01 * AC) - 327.68)","0","3","Volt","7E3"
"HV Battery Block-14 Delta V","HV Delta BK14","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14) - ((2.56 * AD) + (0.01 * AE) - 327.68)","0","3","Volt","7E3"
"HV Battery Delta V","HV Delta","21CE","(((2.56 * (D + F + H + J + L + N + P + R + T + V + X + Z + AB + AD)) + (0.01 * (E + G + I + K + M + O + Q + S + U + W + Y + AA + AC + AE)) - 4587.52) / 14)","0","3","Volt","7E3"

 

Attached is a PDF of my Excel histograms from my 2008 with around 83k miles on it. It has been owned and operated in the Pacific Northwest where the temperatures are relatively mild. If we see a 100 degree day in the summer, it is the talk of the town.

Folklore says HV batteries are driven to an early death by extreme heat (like in the deserts of Arizona).

 

Torque Pro allows multiple vehicle profiles. I've never used this feature, but I'm guessing different custom PIDs for each profile.