Replaced 1 bad cell #9

Peltier coolers are pretty inefficient. I haven't done the calculations, but I'd bet it is more energy efficient to stop using the battery when it gets too hot rather than burn the power trying to actively cool them.

 

Yep, and you still need good airflow to cool the hot side, and it's vital that the heat is removed (vented to outside).

Personally I think they should have run a small duct directly from the A/C and even allowed the A/C to be automatically activated for this specialized purpose. I know that some would be a bit resistant to having the A/C come on beyond their control, what with the reduction of MPG and all. However if it was only above a certain temperature threshold and only a relatively small amount ducted directly to the battery, then I don't think it would hit MPG too hard.

 

There is a hack to make the battery fan run on high. That, and/or having the battery fan run for 10 minutes after shutdown, would help a lot. The most frequent cause of overheating that I have experienced is parking the car at full SoC on a hot day. That happens a lot to people that live in the mountains.

 

I personally feel the charging system in the car will balance the newly installed cell. If a cell will not take a charge then it will give a code. The op stated the pack is behaving like new! H

 

Yep, that was exactly what happened to me last summer. I parked for one hour after going down a fairly decent hill, with the battery on eight green bars. And when I returned to the car the battery was acting really funky. It still had 8 bars but the engine was running all the time, it would hardly use the battery at all, and the MPG's totally went to crap. I actually thought I might have completely rooted the battery, but after it cooled down it eventually went back to normal.

Is that a difficult hack seilerts? I think I'd be interested in trying that next summer.

 

keep on truckin'!

 

Has anyone been able to make this hack while the engine is running? According to Hobbit, it's difficult to do with the electronics powered up.

Prius battery exploration

After you power the system down, turning on the fan is easy but I wanted to engage the fan on high when I know the battery is going to be heated up. For example, when I know the battery is going to be overcharged from going down a long hill, mountains, excessive EV due to stop and go traffic....

 

It has been done on GenIII with Torque OBDII app with custom PIDs.

I am sure the same can be done on your GenII. We'll probably need to find a new PID since I doubt GenIII one will work on GenII.