P0A80 Code- but is it really the hybrid battery

Take an extenal battery, and two leads and touch them to the connectors on the fan.
Someone on here posted which was the positive and which was the negative.
You'll have to do a search for it, unless someone wants to put it here.

Anytime you're searching for a reason a part doesn't work, electrical, you apply the voltage
to it, if it doesn't work, you found it.

 

I guess I am overthinking all the weird data shown in the Dr Prius screenshots. There are enough screenshots that show believable data to come to the conclusion that the battery modules are the problem. The delta state of charge of 32 to 36% is my main concern, which suggests that the battery blocks (maybe block #11) are out of balance with each other. Can you ask the battery shop that you found if they can do a grid charging of the complete battery pack to try a top balancing of the battery. The grid charger that I own outputs 0.35 amps at 250 volts and would take about 24 hours to do a top balance of the battery pack. If they are capable of doing this at a reasonable price, I would try it. It may or may not help, but it will not hurt trying it.

How long did your car sit unused when you replaced the head gasket?

 

I would think that 2 months of non-use would not cause a problem with the battery.

ECUs very rarely go bad per ChapmanF, but the battery smart unit is what I was originally suspecting.

I wanted to say that a top balance to the battery pack will not do any good if a cell is going bad in one of the battery modules. I am also assuming that the hybrid battery is the original in your car, and it was not worked on or replaced by someone before you purchased it in 2022.

 

Why not charge the battery while you're waiting on all this other stuff?
And if you leave it on long it would equal them out. If they are still good.
But proper charging/discharging would be the best thing for them.
Then you would know if any of the cells were truly bad.
Right? You'll likely eliminate the battery, or computers.
Might as well remove all the connectors and clean them while your at it.

 

If you have a grid charger as you say, I wouldn't know if you can do one, two, or more at a time.
I use the Prolong system that has the harness connected so I can charge the whole think at one time.

If you remove the orange safety plug at the right rear of the battery, you'r safe.

 

I did some searching, and the battery cooling fan does not run below 35 degrees C (95F). It turns on to speed 1 when the battery temperature gets to 36C (97F). I will check my battery cooling fan over the next couple of days.

 

I checked my car today. The temperature of the HV battery was 68F, and the cooling fan was not running. I used the Dr Prius app to override the cooling fan and decreased the temperature in the app down to 50F, and the cooling fan came on.

So, if you want to test your cooling fan, wait until a warm day or a sunny day were the interior of the car is above 75F and use the app to see if you can get it to turn on.

 

The C1310 and C1259 trouble codes are just saying that their is a trouble code stored in the HV control ECU, which is the P0A80 that you have.

$400 for a HV battery test is to much in my opinion. I do not know if you would learn anything more then what the Dr Prius app is telling you.

What is the delta SOC now?

I think your battery pack is a good candidate for reconditioning (3 charging and discharging cycles).Can the hybrid battery shop that you found do reconditioning of the battery pack using a grid charger and discharger?

 

For about $650 you can get the Prolong system and likely bring it back to life.
And make it last a lot longer. You can do 4 charges, and 3 discharges. The last
charge you should do for about 12 hours once it's leveled out at it's maximum charge.

 

Yes, ou have to pull the back seat, easy, remove the hybrid battery cover, again easy.
There are only 2 wires to attach, but if the bus bars look corroded, you should remove them
and clean them up with water and baking soda.
Then you remove the blower motor connector and connect the harness to that connector and the
fan to the harness. Then route the harness to the back of the trunk so you can get to it easily.

Then it's just switching the charger and discharger...

It has worked for me for several years....

 

The wiring harness needs to be installed to the hybrid battery and cooling fan like ASRDogman says in post #99.. Once that is completed, then you connect it to the charger or the discharger which is very easy. See hybridautomotive.com

I purchased my Prolong deluxe system used on eBAY 3 years ago. I recondition my battery one time per year. It has worked great for me, 2011 Prius with 142k miles.

Edit: I reconditioned my battery the first week of February this year. I did the Dr Prius life expectancy test 4 weeks ago, and it said I had 104% capacity left, which can not be correct, but my battery is in very good condition.