Cell failure at position 9

What kind of an answer do you expect, exactly ??
Nobody here has super-natural powers of perception.

Either: You are putting in used cells which would be expected to fail fairly soon.
OR
You are doing something wrong.

More information is needed to make even a wild guess.

In general, all the cells need to be balanced fairly close in the beginning.
One that is way off might be likely to STAY way off.

 

sorry, i was out most of the day, but i have the solution to your problem

 

It's common for people who don't know any better to sell bad replacement modules. You need to find a better source, or get replacements under warranty from person you bought from.

 

When you say 'Cell failure at position 9', is that based on your scan tool information, or from your physical examination of all the modules?

You are counting incorrectly, The block and module count starts from the end opposite the electronics bay if you want to be in synch with the information you will get from your diagnostic scan tool..



The one that the negative post is connected to the emergency Orange pull-out plug is module 20 (in block 10).

Have you load test all your modules to ascertain that module 20 is the only module with issues? How are you verifing that the replacement module is a good candidate that matches your other 27 modules?

 

It is more likely the fact that this module was introduced into your pack by you and it had a lesser capacity (at that time) compared to the others or degraded at a higher rate than the other original modules.

OCV in and of itself does not tell you very much. It certainly does not tell you anything about whether the cells within the module are balanced with each other. It will not tell what the capacity of the module is either. You are really hoping and praying at this point.

In a quick summary, to balance each module you need to first charge the module and then do a gentle (0.05C = 325 mA) charge for a further 4 hours. You then need to do several cycles of discharge/charge (usually recommended to do 3 rounds, sometimes up to 5) with the final charge again to full followed by a last gentle 0.05C charge for a further 4 hours. You need to record the results of each charge or discharge - start voltage, end voltage, start time, end time, Ah put in (if your charger can supply that information), etc. Once you have completed this process on all of your 28 modules you can do a 120-second load test using a 55/60W halogen headlight bulb (wire up both high and low beam) recording the starting voltage (before applying the load) and the ending voltage (before removing the load). Record these voltages for each module. Subtract the end voltage from the start voltage and record the difference for each module. Do this process for all modules you intend to use as replacements. At this point, you can look at the difference in voltage for all the modules and weed out all modules that have the largest difference in voltage. The variation is 0.2 -0.3 V. Others with more experience on single module rehab and can advise whether that is a good recommendation or not.

How good your rehab of the battery depends on how accurate and consistent you do this process. Even so, when you have done all this there is no guarantee that the battery will last for more than 6 - 18 months.

There are many posts on PriusChat that give more details if you require that. Look for posts by @PriusCamper who can guide you with the finer points.

 

You can try adding water to the modular battery. Due to long-term operation and sometimes high temperature, the battery cells of the components may dry up, thereby affecting performance. Before doing all the work, you'd better check the performance of the module under different working conditions. When charging, such as high current charging generated by downhill braking and regeneration, higher voltage modules will not perform well. When high current discharge, such as switching to EV mode for acceleration, the low voltage of the module is not good, if you already know which module is not performing well. Moisturize or replace the bad module (although I did not succeed in adding water, it does not mean that you cannot succeed, the modules seem to be different), I believe it can solve the problem.

 

Nobody in all the years that this has been talked about has found a way to do the reliably and repeatedly. It wouldn't be for the faint of heart nor if you needed a reliable repair in the shortest time. If you have plenty of time and like to tinker, have at it.

 

Although I don’t want to add water to the battery to be useless, I have to admit that this is true for some cells. What I want to say is that I once owned a Honda civic generation 1 hybrid car. That car used to have ima (hybrid) lights. It’s bright because the capacity is too low. After I drilled a hole and added water, I sealed it with solder. The capacity has been greatly restored. At least in the next 3 months, the ima light did not light up, and the battery temperature was so low that I suspected it. There was a problem with the fan or the sensor. Later, I bought the obd to test that the fan was normal. The data flow showed that the sensor was normal. Later, I sold the car. Compared with Honda’s cylindrical cell, it’s difficult to seal it. I’m not sure whether the solder is stable under the corrosion of potassium hydroxide. Toyota’s plastic battery box is very good. I think it might be the structural strength or material of the cell. , Will lead to different results