the electric battery or traction battery

Your car has 3 Batteries:

A NiMH High Voltage battery, often called the Traction Battery. It has a 100,000 mile/ 8 year warranty in your state.

A Lead Acid 12 volt battery sometimes called the accessory battery. I doubt it has any warranty left. It is the most likely at fault, below are some places to buy one.

There is a CR1632 in the Fob, it has no warranty. (but I doubt it is at fault in your scenario)

Optima DS46B24R Optima battery direct fit replacement for Prius 2004 + , Prius V & Plug-in Prius with Instructions
Exide AGM Car Battery (Group S46B24R)

 

Fob battery is CR1632, agree though that this battery is unlikely to cause symptoms encountered by OP.

SCH-I535

 

It sounds like it could be an inverter failure which I believe is covered by a 8 year 100,000 mile warranty

 

You need to take it to your dealer and have them look at the Diagnostic Trouble Codes (DTC) and troubleshoot the problem. Depending on the fault codes they will be able to tell you what the problem is and whether the failed component is covered under warranty or not. If it is covered under warranty they should be able to repair it at no cost to you.

If it is not covered under warranty they will give you the cost to repair. In this case you will probably want to post the DTC's here and find out what your options may be to help save some money.

 

I had my inverter fail on me. The engine wouldn't start but the car would crawl on ev, well until the battery ran low - no engine to charge it back up.

 

Make sure you get a copy of complete list of all the codes it has thrown. They will look like PXXXX-XXX.

The check engine lights will store these codes telling the dealer exactly what the car was unhappy about. This may prove very helpful TO YOU if it turns ugly like dealer blaming you that you ran out of gas for instance and caused traction battery to fail (OOW) and you did not. The codes will tell us and you what really happened.

Seen many stories here about what started as simple IW repairs gone stupid by incompetent dealer techs. The usual being they can't figure it out and start throwing very expensive parts at it on your dime.

 

I have a 2005 Prius (love it) and I'm getting ready to replace it with a new one. My concern is that I travel for extended periods and I'm worried about the battery going dead while I'm away. Considering getting a different vehicle unless I can figure out how to prevent the battery from going dead.

 

Assuming you'll be parked somewhere secure with electrical outlets, get a lowish wattage smart charger, something you can leave hooked up indefinitely. There's nothing all that different about the Prius, any vehicle can get a run down 12 volt battery, if it sits too long. OTOH, the capacity of the Prius 12 volt battery isn't that good.

 

Is it the large high-voltage traction battery you're worried about, or the 12-volt battery? The former will probably be OK, unless it's already on its last legs, or your absence is very long. As for the 12-volt, do what Mendel suggests, or disconnect it.

 

To the OP, DO NOT mess with the traction battery! It IS on warranty unless you mess with it!

Yes, you will have to get the car towed to a dealer. No, the traction battery can not be charged by you. It's a 200V battery and can be very dangerous if you don't have the proper equipment and training.

If you ran the car out of fuel you will have to pay for at least some portion of the repair. If you didn't it will probably be covered.

To Jani, you can purchase a "Battery Tender". It is designed to be left on a 12V lead acid battery for long periods of time, such as over winter (motorcycle and ATV use). It WILL NOT damage the battery. You will need to plug it in to 115V AC. You can connect it to either the battery or to the "boost terminal" under the hood. I use one every winter on Pearl S.

Most modern cars will have problems with the 12V battery if left for periods longer than about 1-2 months. They all have lots of "parasitic loads" that will drain the battery. While the Prius has a rather "small" 12V battery, there are other cars that do as well.

Your second option is to install a battery switch. Put it in the line on the negative terminal. You can then disconnect the battery. The downside to this is you will loose all programming in the car. Things like radio stations, the state of the cars backup beeper, the auto window rolldown settings. Most are easy to set, particularly if you have the GPS screen. You will also loose any codes that the car detected. This can be good or bad.