Total battery power loss after 7 day vacation!

My guess would be that you left an internal light on in the car. The usual culprit is the light in the cargo area.

There is no way to put the car in neutral without power.

 

If the car was locked by the SKS I'd believe all the lights were off. If water is shorting the battery either the engine compartment or the rear deck is flooded and the 12v would be the least of your problems. Could just be a crap battery. It's under warranty so I'd have the dealer pick it up or send the Prius Tech out, their choice.

 

On the Gen II Prius, some of the lights don't go out when shutting the door. Are there any lights like that on the Gen III?

Tom

 

Here are my ideas. Just after purchasing my III I left for an 8 day vacation. I had heard on the board some talk about dead batteries and was wondering if it would affect me. When I came back all was fine and as far as I could tell the 12V battery was very strong.

Do you have an aftermarket or port installed alarm (in addition to the keyless entry)? If yes, then there might be two things that could have happened.
1. The rain kept setting off the alarm which could quickly kill the tiny 12v batt.
2. The alarm has a power leak somewhere that is slowly draining power from the battery. I had this happen in a 4Runner of mine with an Alpine alarm system. I eventually had to have it swapped out for a completely different alarm.

 

Map lights and rear cargo lights stay on indefinitely... I've left the map lights on overnight a few times.

I have not driven my Prius III for at least 7 days since I bought it (I have a motorcycle I often use for commuting -- I _can_ go in the carpool lane with that.) And never had a problem.

I have the stupid dealer installed alarm too sucking power...

Something is wrong with the car.

 

It's possible it's the alarm but without narrowing the problem down it would be difficult to tell. The way I figured it out with my 4Runner is I pulled the fuse for the alarm and let it sit for a week and put it back and let it sit for a week. When the fuse was in my battery would die in about 3 days.

The coment about the battery not being used to not being used is BS. Batteries don't work that way.

 

About 2 months after delivery I had the 12v in my 2010 V drain in 4 days as it sat in a parking garage. Turned out I'd pushed one of the dome lights on to gather interior stuff (the parking spot was dark) and then simply left it on. Doesn't take long if one does that!

 

I'd call the alarm a Prime Suspect, and agree that the roadside assistant story is crap.

Do you have access to an ammeter to measure the alarm's current load? It should be a few 10s of mA. If it takes over 100mA, it will be a battery killer.

Because the Prius 12V battery is smaller than in most cars, an alarm drawing too much current will kill it faster.

When a coworker suffered this problem, it was a faulty installation, not a defective alarm.

 

I am concerned about this on my 2010, since I expect to be away for weeks, and because I had this problem repeatably on my 2001 Prius. I measured the current on that car as 40 MA with all off, after waiting a while. I expect the gen 3 to exceed that. After the first 2 dead cases, I took to disconnecting the 12V battery during long trips. The car started normally when re-connected, but of course the clock and radio needed re-setting. On my new car, I think I will connect a trickle charger to the jump-start connections under the hood.

 

I have an issue that may be directly or tangentially related: I keep a 07 Prius garaged at a separate location from my home where it may not be used for 6-10 days at a time. Lately I've had to jump the car when coming back to it after a break. The vehicle is parked in the garage located directly below the kitchen drawer where the key is stored when I'm away. It is a keyless entry fob, so I'm wondering if there is something going on there that could be the cause. Thoughts?

 

I take it by idle you don't mean the engine was idling...

 

I just re-checked, and the cargo area light on my Gen III goes ON when I open the hatch, and goes OFF when I close the latch, locked or not. Eliminate that possibility.

 

For those of you that are having this problem. Next time you are leaving the car for an extended period and you're sure it will be dead when you get back. Pull the fuse to the alarm before you go. You'll no for sure if it;s the alarm when you get back.

 

Let me get this straight:

If the battery dies, you can't get the car out of Park? That's a serious problem, especially for those of us who park in a garage...

 

My Gen III has a switch just above the cargo area light where you can toggle on and override the door latch, just like the dome/map lights.