Gen 2 and Gen 3 HV Battery Interchangeable? Modules Interchageable?

You should remove all 28 modules from the Gen3 pack and put it in your Gen2 case. You can then sell the individual modules from the Gen2 battery pack.

 

I'm not an expert but, it is my understanding that the modules must be swapped into the Gen II case.

 

The batteries are not compatible, but the 28 battery modules are. You will need to disassemble bot batteries and swap the 28 modules from the 2010 battery into the 2007 battery. I would suggest also following the re-balancing. load testing and equalization steps outlined in many HV battery discussions here on PC while you have the 2010 battery intact and out of the car. You can probably use your Prius with its old battery for a while while you get the 2010 modules ready for installation.

If you then go through the same steps on your 2007 modules and document their performance, the better ones can be sold to others to fix their batteries.

JeffD

 

I follow nearly every battery replacement thread on here and I've never seen someone try that. You could be the first though.

 

I'm no expert at this but I think it would ok to just swap the new Gen3 modules over to the Gen2 case. If the modules haven't sat around for a long period of time, it shouldn't need to be re-balanced if you are swapping the entire pack over. If you have the equipment, balance it, but if you don't have the equipment, you can just swap the modules in and give it a go. The modules should all read a similar voltage, check them all before you install. Last time I read the ones in my Gen2, they were mostly at 7.6 volts, except for the 2 end modules that read 7.5 volts.

 

As long as the battery modules are reasonably balanced and you at least put the set in parallel to equalize (get them all to the same voltage) them, there should be no immediate codes.

JeffD

 

I thought I saw someone on ebay that would rebuild gen 2 batteries with gen 3. Do a search. I thought I saw someone here do this with great detail.

 

straight swap without balancing?

 

Would you please check back periodically with how things are going? Maybe near 1st of year and 4th of July, just to confirm this is still working for you. Thanks!

 

Any updates?

 

I was going to mention, no need for all the re-balancing equipment, if you are swapping with known good modules, just put them in and drive the car, to charge cycle them a few times. Drive it uphill (discharge) then down hill with brakes on to regen charge them. The system will balance them out and any cells that are NG will show rather quickly. One thing I would add is if you're going to do all this work and have the pack out, move the temp sensors (3 of them) to the top side of the modules. Heat rises! Never understood why they mounted one of them on the bottom, and it wasn't even touching the module! Move all temp sensors to the top side of the pack!

 

Allow me to help you understand. On a Gen 2 HV battery:

One temp sensor is mounted on top of the battery, near where the cooling air flow enters the battery pack. This one clips into a small metal tab located on the clamping bars and is suspended in the airstream. It's job is to monitor the incoming cooling air temperature.

There are three temperature sensors located on the bottom of the pack, each one clipped to the bottom of a module. One at each end and one in the middle of the pack. These are physically inserted into recesses in the module body and monitor the actual temperature of the modules, not the air.

Cooling air from the fan enters the top of the battery case, flows downward between each module and into the lower plenum. It then exits through the plastic duct and leaves the car via the penetration by the 12v battery.

Moving the lower temperature sensors to the top of the battery would put them directly into the path of the incoming airflow prior to it actually removing any heat from the modules.

Heat rises because hot air rises. Hot air only rises if it's not part of forced circulation. The fan runs all the time, usually on speed 1 or 2, always maintaining flow direction from top of battery to the bottom. So in this case, warm air actually always flows downward.

 

Although most cases seem to be replacing gen 2 modules by gen 3 modules, I believe this post proves that they are actually really interchangeable. So, the other way around would also work? My situation is that I accumulated a bunch of modules from differences which could be gen 2 and/or gen 3, and now I'm contemplating to install them into a gen 3 Prius.