The Prius has two batteries, a large traction battery and a small 12V auxiliary battery.
1. If the small battery dies, you jump start the Prius from the jumper terminals under the hood. The owners manual has the instructions on where to find the jumper terminals. The Prius needs very little to start because the 12V battery only has to power on the computers and throw the relay.
2. If the traction battery dies (and this just hasn't been a problem), then there is a special charger that not every dealer has. However, these chargers have only been used a handful of times.
The Prius needs the electrical system to be functioning in order to drive. This hasn't been a problem either. If you ever needed a traction battery, and it wasn't covered under warranty, the cost of a replacement battery for a 2005 is under $2000.
http://www.trademotion.com/partlocat...layCatalogid=0
However the chances of you ever needing to replace the battery are lower than having to replace a transmission in an old fashioned car.
http://www.ctvbc.ctv.ca/servlet/an/l...shColumbiaHome
All that is known about Prius battery failures comes from the older 2001-2003 Prius. Starting in 2004 an improved battery was used which has a much longer life. Even so, the majority of 2001-2003 Prius are on the original battery. My 2001 Prius is among them. The typical life seems to be 200,000 to 300,000 miles for the older style batteries. If you had a 2001-2003 Prius there are three options:
1. Replace the battery with a new one for under $2000.
2. Get a rebuilt battery from
http://www.re-involt.com/ These batteries are rebuilt with the 2004+ cells so they have the potential of lasting longer than the OE battery. In addition, they are lower cost.
3. Find a wrecked 2001-2003 Prius and get the battery out of that one (about $500).
There are no rebuilt 2004+ batteries because there just haven't been failures.