My 12 volt battery saga with my 2004 Prius began in 2007 and continued through 2014. I would hop in the little darling only to discover she was dead as an armadillo on the side of the road. For the next seven years, off and on,my little Prius regularly needed to be jumped. I have spent untold non-interesting hours hours at Toyota dealers from Texas to Virginia. During that time I purchased and paid to have installed six batteries. Six. My problem was not fixed until I went to an INDEPENDENT garage in Great Falls, VA.
11-05-07 replace battery
4-28-08 replace battery
4-24-09 replace battery
10-26-10 replace battery
10-27-11 replace battery. Dealer stated NO ELECTRICAL DRAINS FOUND.
12-04-12 test and charge battery . I told them of ongoing issue.
03-15-13 test and charge battery. I restated the on going issue.
01-15-14 Great Falls Auto Service finds a .19A draw due to an aftermarket tracking device installed behind dashboard. (I found this garage through the Car Talk website link Find a Mechanic. Thanks, guys!)
01-31-14 replace battery.
I did not put in the aftermarket tracking device. I bought the car six months old from the owner who had purchased it from Champion Toyota in Austin. They never found the device even though it was possibly put in by them (not sure) and they were doing my maintenance for the first four years.
Meanwhile Koons tried to suck more blood from my wallet than the armadillo lost after being run over. They seem to be fairly unsavory in their service practices.
Champion Toyota may have used this as a rental. Rental vehicles commonly have tracking devices installed. Rental agencies have fine print that adds a fee every time the renter leaves the state. The tracking devices are set up to automatically add the charge.
In CA a lawyer attended a conference of some length. He stayed at a hotel just out of state, and the conference was just over the state line. At the end of the week he was hit with a bill for thousands. He sued. CA now has legislation prohibiting this practice. NY had a similar incident, and now has statutes prohibiting this practice as well.
The Prius has a smaller 12V battery than a “regular” car, with less capacity.
0.19A would be tolerable on a full size 12V battery if driven at least every few days, but too much for the little Prius battery, as you’ve found out.
Too bad the other shops didn’t have the competence to do a parasitic drain test right off the bat, that’s what I would have done.
Sometimes those sneaky devices are installed in new cars by the dealer in case the owner stops making payments and attempts to hide the car to prevent it being towed back to the dealer, repossession for non-payment. There’s another device that can cause problems too the dealers sometimes install, an anti-theft gadget, that prevents the car from being started and driven from the lot unless a car salesman is there and knows how to disable it. I had that latter device unknowingly (by me) installed on my Corolla when I purchased it new, and it caused a host of starting problems until I finally figured out something was there in the wiring that wasn’t supposed to be.