2010 Prius: Hybrid Battery or Aux?

Does anyone know whether the 12v auxiliary battery self diagnosed at 11.6v (13.5v when powered on) could actually cause a PA080 error code, triangle w/exclamation, and check hybrid system messages? We had to replace the aux a few years back when the car completely didn't start. Try testing the HV battery the other day using Hybrid Assistant but the combustion engine is always on and the battery will only charge up to 64% when driving. HV will not charge when stepping on the brake and gas in Drive mode, even continuously for 5 minutes. It also won't discharge to two bars, the charge will only stay between 52% - 64%. Therefore, I was unable to complete the battery test via HA. Just trying to figure out if it's the aux that needs replacing again or does the HV finally needs replacing after almost 200K miles. Dealer wants $3,650 but Green Tec can install brand new for $2,200 in their shop. We love our Prius, it has been a work horse for our family. Hopefully, if the HV does need replacing, a new one will allow it to go another 200K miles.