Whats wrong with this procedure? The HV battery is connected in series , the ECU reads in banks of 2

I like your unique method of exercising the pack. This prevents the weakest modules from going negative voltage, reversing polarity.

To locate the weakest modules, monitor the pack in real time, while doing a full throttle acceleration from a dead stop. A strong pack will deliver 150 amps. Cycle the weakest modules right in the car. Module rehydration may be necessary to give a kick in the pants to stubborn modules.

Attached pic, module #27 was replaced after test shown. Neither cycling or rehydrating helped this module.

 

Absolutely. Google charging batteries in parallel to learn more. The voltage of a battery has little to do with it's capacity, otherwise why would I buy a 1.5 volt 'D' cell battery if I could just buy a 1.5 volt hearing aid battery or 1.5 volt AAA battery?

It is not the voltage applied to a module that 'rejuvenates' it, it's the current that is forced through it. With 28 modules in parallel, current mostly just goes to the one of least resistance...

 

I agree with TMR-JWAP that the big concern with your method is that the current does not get equally split between the 28 modules.

I am curious, how long did you let each charge cycle run?

At this point you might as well try to start the car.

 

Yes, absolutely, the current is not equally split.
Let's take two modules, a strong and weak one, connected in parallel. Apply a one amp load. At first each module is being drawn down about one half amp. As the voltage drops, current will flow to the weaker. So the stronger module "sees" a higher load, the weaker less. But both modules ARE being cycled, with a variable rate load. Log this variable rate, and do the above test to each module alone. Same result. The modules are being cycled.

 

I would really like to know the results of your experiments. Have you tried to start the car?

The variance in module internal resistance is not significant in this set up. Look closely at how the parallel harness is made. The picture shows the pack being charged with the power supply leads connected to the module on the far right. For current to reach the second module it must pass through 5 ft of what looks like 18 ga wire and 28 crimp connections. So the first module with the direct connection has about 20 milli ohms resistance and the next one could have ten times that resistance. It's the quality of the crimped connections that's the real wild card. Every other module is being charged through a different length of wire and number of crimp connections.

Then there is the issue of the negative delta V when NiMH is fully charged. Parallel charging can be a good way to start a fire.

 

I think the real problem is the gas engine is not running. It's easy to get fooled by the electric motors spinning the engine for a few seconds and then stopping.

Clean the MAF sensor!

I'll ask again. How long did your charge cycles run for?

 

Are you continuously disconnecting the 12v, which would clear the codes before scanning?

The OBD2 scanners being used aren't fully hybrid compatible. It would be economically prudent to just get a 'mini-vci' cable ($20) and use techstream (dealer tech software) on a windows device, then you will be able to retrieve the codes at anytime for less cost.

Can you please post an image of what was cut? (use 'copy and paste' in your posting, copy is control-C and then paste is control-V)

 

Click on the "Upload a File" button and then select the picture in your album.

 

That ground strap is not keeping your car from starting. The half that's showing in your picture is installed upside down. The HV cables have a braided shield mutch like a coaxial cable. The chrome strap grounds this outer braiding. The braiding does not carry any current. The only two reasons I can think of for this ground is radio interference or a fail safe if the cables were to be damaged in an accident.

At the risk of breaking your good Prius you could try swapping the batteries between your two Prius. I think you will find the problem is not the battery but is the engine in your project car.

So, How many hours did you let the charge cycles run for?

 

If Techstream isn't in your future, then maybe an OBD2 bluetooth adapter with an App like Dr Prius or Torque would be helpful