These are the codes from code reader

The Hybrid Battery check looks at the voltage differences at the module level, not toe total voltage. If there is too great a difference (1 volt?) the code is thrown because one or more modules are detected as failing. The freeze frame data gives codes identifying the modules, IIRC.
There could be other issues triggering that code though.
How many miles on the car?
@TMR-JWAP @2k1Toaster and @Raytheeagle have worked quite a bit with the batteries. In fact. 2k1Toaster sells a replacement detailed in my signature. It is $1600 delivered to continental US, but I think it is currently backordered.

What is the voltage of the 12 volt battery after it has been sitting for a while? It can cause the computers to get confused and throw random trouble codes.

 

Bisco.......take note of this.

 

11.9 is a tad bit more than half discharged.
Charge or replace the 12 V battery first.
Other stuff might be wrong too.......but you can't trust "trouble codes" with a weak 12 V battery.

 

Disconnect the battery, at least one side, then charge thoroughly.
Then let it sit still disconnected for a few hours; overnight is better.
IF.....the voltage then is not 12.6 or more, it isn't able to hold a change anymore and needs to be replaced.

Having it disconnected will reset the codes. Charging in place without disconnecting will not reset/clear the codes.

 

Sometimes disconnecting the 12 volt battery resets the codes. Usually, once a 12 volt battery requires recharging it is failing and due for replacement. If this is the original 12 volt battery it is long overdue for replacement anyway.

 

What device are you using to read the codes, and what are the codes offered?

 

codes listed in the first post

 

Pretty sure we're still missing some. But if you have others please share.

 

There's a battery side of the contactor and a car side of the contactor. Battery side will always be hot the car side is only hot when the contactor closes and connects the hybrid battery to the car/inverter.

I do not mean to be rude or demeaning but this is very basic electronics so you don't have alot of experience with this so be very careful around a hot hybrid battery without the safety plug removed. It can turn your hat around as electricians like to say.

And it doesn't really matter what the total output of the battery measures in your case it was 188 volts. That's a little low but what does matter is the battery ecu monitors every one of the battery modules and if one falls below minimum voltage compared to the others it will throw a nag. The reason its below voltage is the module is old and not able to hold a charge. Its failing. The ecu knows what it should be and its not where it should be so it throws a nag.
The difference in voltage between a good module and a bad module is typically referred to as Delta.

 

Each module has 6 cells and each cell is 1.2 volts. Each block has 2 modules and there are 14 blocks in the battery pack.

188 volts seems low (lower than I have read).

Can you give us a bit of history with your Prius:

• Did the car sit for awhile?
• Has the battery ever been depleted severely (like ran out of gas)?
• What are the Hybrid specific codes (if you are getting P0A80 that is the generic and you should have something more specific to point you in the right direction)?
• Where in the great US are you located?

Keep us posted .

 

• Did the car sit for awhile?

• Has the battery ever been depleted severely (like ran out of gas)?

• What are the Hybrid specific codes (if you are getting P0A80 that is the generic and you should have something more specific to point you in the right direction)?

• Where in the great US are you located?

These are the things we need to know. 189 volts is not just a little low, it's completely jacked. 189 volts and 28 modules means you're averaging only 6.75 volts per module. I'll go with the guess that this has been sitting a LONG time. You're going nowhere until you get the HV voltage up.

The 201.6 volt rating is merely 7.2v nominal x 28, but 7.2 is not the normal voltage. Normal is usually in the 7.7+v range