.19 v drain on battery

I think you mean .19 amp drain. Is that right? How much do you drive the car normally? Miles per week, how often, that sort of thing. Do you have SKS? If so, it should be turned off when not in use, which reduces drain a bit.

.19 amp drain over 24 hours is 4.5 amp-hour. The battery has much more usable capacity than that, and should not go flat in 2 days. However, if you drive only brief trips and only occasionally, then it may not get fully recharged. The best thing to do would be to get a small battery tender and clip that on the battery while the car is idle.

To sort out a problem like this requires using a clamp on amp meter and checking each branch of the circuitry from the battery onwards, and looking for the offending section. One can do some of that with pulling fuses, but in the Prius there are quite a few of the ECU's that are supplied by non-removable fuses, and thus require using said clamp on amp meter.

 

Do you have any aftermarket accessories or additions that use electricity? If so, please describe.

 

Daisy - even a few hundred miles a week is not enough to fully top off the battery unless it was done in a single trip, and even then it might not be enough if the drain back then was as significant as it is now. Good luck finding the source of the drain.

 

Normal quiescent current drain is 0.02A compared to your car at 0.19A.

My guess is that a relay is stuck. As previously stated, it is necessary to use an ammeter to determine which fused circuit has the excess current drain, then look downstream from that point (with reference to the electrical wiring diagram) to see what components source power from that fuse. Then examine each component to determine its current drain. That is a time consuming process but should not take five days.

At this point you could reasonably question whether the garage staff has the technical ability to locate the problem. You may need to have the 12V battery fully-charged, then move on to a more capable shop.

 

It may have been installed as a tracking device, assuming the purchaser was "unreliable". Some cars are equipped with "shutdown" devices that can disable the car if the purchaser didn't show up to make the weekly payment.