Battery

There is a 12V battery in the left side of the "trunk" that powers the accessories and the computers which start the car. This battery has been shown to discharge if the car is not used for two weeks or more. The hybrid battery never discharges since there are so many protections built into the car to prevent it doing so. There are Prii on the road with over 200,000 miles with no hybrid battery failure.

If the 12V battery gets run down, you cannot start the car. There are contacts under the hood to jump start the car in that case. It is described in the Owner's Manual. You should never have to worry about the hybrid battery.

 

there is a regular battery in the car, in addition to the hybrid battery. the battery is located under the trunk, on the passenger side, all though you can access it for jumping from the black fuse box under the hood of the car. If you're going to be gone for a while, it's recommended that you turn of SKS (it looks like you have a pck 7) by pushing the little button beneath the steering wheel when you leave. you'll then have to click the remote or use the mechanical key to get back into the car. also, you'll have to put the key into the slot to drive whenever the SKS is disabled.

for extended trips (say 2 weeks or more), it's also recomended that you disconnect the battery to keep it from going dead.

I think that answers the first question, now for the hybrid battery... in short, the car won't let you do anything to damage the hybrid battery. when the car is off, the battery is disconnected from the car, making draining it practically impossible. Even if it were near dead, the gas engine would kick in to recharge it. the aux (or normal) battery is the one that starts the car. all it does is boot the computers and connect the hybrid battery to the system so you can drive.

 

<div class='quotetop'>QUOTE(ladyinblack @ Jul 20 2006, 01:35 PM) [snapback]289569[/snapback]</div>

There is a 12V battery in the car. It's located under the floor of the trunk area on the right toward the rear (in 2006 models at least, and presumably in 2005's and earlier).

It's not a "normal" size, more like a motorcycle-sized battery. That's because it does not need to provide cranking amps for the engine, since the hybrid battery does that task. The 12v battery runs the electronics and lights in the car, including all the computers that run the hybrid system. So if that battery went flat, you wouldn't be able to start the car.

On the other hand, if the hybrid battery pack went flat, you wouldn't be able to start the engine either, since it provides the cranking power for the engine.

But don't worry: as far as I can tell, the only way you can run the hybrid battery dry is if something else is broken. It's not that likely to happen. In fact, of all the things that have been reported on this forum that have gone wrong, the battery going flat has never been one of the issues (at least while I've been reading). The closest we've come is a couple of people whose inverters have gone bad, causing the car to stall.

 

I'm sure that if you left a Prius out in a hot environment for a few months... maybe a year... without being started, the hybrid battery would completely deplete. It's just like any other battery -- non-ideal and with some amount of leakage current -- so it does have a "shelf-life" to its charge retention.