Need new battery, what else?

I recently bought a 2005 Prius with 164,000 miles knowing the red triangle warning light, check engine light and VSC lights were on and that it wasn’t running quite right. All signs that the battery needs to be replaced, which I plan to do with one from newpriusbatteries, but I’m wondering if the ecu may be bad or anything else as well. I hooked it up to a Mini VCI to see what the codes were and got P0A1F, P3000-123, C1259, C1310, U0123, U0124, U0126.


I’ve been reading up on all the threads but am stumped on where I should start. The attached pictures show my freeze frame from techstream, the battery voltages are all over the place, including many negative (-25.07V up to 24.98V). I can’t find anywhere that talks about this kind of situation. If I try to clear the codes they come back immediately. Any help on where to begin diagnosing would be greatly appreciated!