I tried to start my Sienna after a few days of just sitting on the driveway because there was no need to move it or drive anywhere, and it didn't start, so I proceeded to jump it. I was told, previously, by the dealer service advisor some time ago that the battery needed to be replaced...... the day finally came. Battery prices will vary by store and sometimes the warranties might vary as well. I am just showing here how I replaced the battery on my vehicle. If you don't feel comfortable doing it, take it to the dealer or to an auto parts store, if they offer the service. Keep in mind that, if you do it yourself, you will be doing it at your own risk. I still have to do the placement of the anti corrosion pads or grease.