Replaced hybrid battery - No power, won't start

2007 Prius with 160K miles. Last month it threw the red triangle of death with code "P0A80 Replace Hybrid Battery Pack". Techstream showed that Battery Block 11 had very low voltage (13.6v) compared to others (15v+). Car was running fine till then, but getting poor mpg (about 36-38). I stopped driving it immediately after the red triangle came up.

Pulled the hybrid battery, tested each cell and sure enough one cell was dead (6.51v). I tested all other cells with a hobby charger. Most tested at about 7.8v and 4500mAH or higher capacity after 3-5 discharge-charge cycles. Only two cells were below 4000 mAh. I planned to buy three reconditioned cells and replace the dead & failing cells.

While looking for reconditioned cells on Facebook, I came across someone selling a whole battery pack from a wrecked 2013 Prius for $200. Took a chance and bought the battery, and it turned out to be in great shape. All cells tested 8.0v or higher, and I randomly tested a few cells with 3 discharge-charge cycles and they all showed 5500-6000 mAh capacity. So I took that cell pack and put in in my 2007 battery and installed it in the car today.

Was all excited, but when I pressed the power button nothing happened - no dash lights, no engine start, nothing. But the interior lights work, car locks and unlocks properly with the key fob.

- I checked the orange service plug half-a-dozen times, and it is installed properly.
- I removed the three connectors to the battery and reconnected them ensuring they are seated properly.
- I checked that the small connector under the service plug is properly seated.
- I disconnected the 12V battery (reads 13.2V with a multi-meter), waited a minute and re-connected it.

No luck, car remains dead.

What am I missing? What could've gone wrong? Is there a fuse or relay that could cause this?
I want to test the voltage at the battery main connectors with the service plug installed, is that safe?

Any suggestions on how to debug would be welcome. I am trying to avoid having to dis-assemble the whole battery again, but will do it if all else fails.

Thanks.

 

With the battery in the car and with the Orange Safety plug in, I measured the voltage at the two main (frame) connectors - it is ZERO. I read in another thread, that the voltage at the main connectors only shows when the car is in READY and the relays are closed.

Removed all the brackets and pulled the bracket out again (what a chore!), and tested each cell. All tested between 7.5v and 8.0v. Then with the orange plug in, I tested voltage across the pack - 219.6v. So, I think the battery is good, might be the fuse as the @TMR-JWAP suggested.

I will check the fuse.

And yes, I was getting the P1121 code intermittently for the past year, was planning to replace the coolant valve but never got around to it. Will do it once I get the car started.

Battery polarities - both 12V and the Hybrid are correct. Rechecked this morning.

Yes, the door ajar light and the key light show up. It is not the combination meter failure, I am sure of that.

I will check the fuses and test the CAN network as suggested. Will report back in the afternoon with my findings.

Thanks for all the advice.

 

This post talks about a "sticky" relay when car has been sitting unused for long. I am going to check that.

Its been raining off an on and I couldn't work on the car this morning, but a quick check showed that the AM2 fuse is fine. Battery voltage is also good and showing 219.6V across the pack.