I have a 2005 that I drive most every day without problem. I do have one quirk that I haven't heard of before. If I don't drive it for 3-4 days, it just won't start without a jump. My understanding is that is should be able to go much longer than this without use. I replaced the auxiliary battery last year in attempt to fix the problem, but it just happened to me again. I would guess it's a wiring problem? My two conversations with the dealer have not gone well at all. I'm told that everything checks out fine. "Yes, because I just drove it here," I seethe (politely). I've joked about having to take my car for a walk often enough that it's just practice now. As I am riding my bike around the neighborhood more, including going to work, you can see how this is going to become a much bigger issue in the near future. Of course I'm looking into a second opinion. If need be I am willing to leave it with a shop for a few days so they can see the problem firsthand while I go about my merry way in a rental. I'd like to avoid that route/expense! I checked the stickies and searched the forum, but perhaps not well enough. Has anyone heard of this before? Or have any advice for me?
Some thoughts from a nonexpert: It sounds like the aux bat is running down while parked. Something might be draining it...rear overhead light ? Check all lights, hatch and doors to be sure they're secure. Are the cables securely attached to the battery ? Has the battery been abused by frequently run down by radio etc? Have the "new" battery checked to see if it has lost its ability to hold a charge. At just over 1 year old it may be defective and probably eligible for a free or very cheap replacement.
If it indeed is a 2005, and it's the original battery, time to dump it and get a new battery. The old one is just used up!! The battery of choice is the Yellowtop Optima. Here is a site that is in So Cal, you could drive over and pick up the battery, well if your car will start, or they will ship it to you. I got a battery about 4 months ago from them, they also have the kit to adapt it to the Prius! Here is the URL... Prius parts
1. If you have access to a digital multimeter, you can measure quiescent current draw from the 12V battery when the Prius is IG-OFF, by disconnecting the negative terminal cable where it connects to the body, and putting the DMM in series. Should be around 20 mA. If much more, then your car has a problem. 2. If #1 does not show any problems, you may need to hook up a battery charger weekly, or else use a battery minder, in order to keep the 12V battery charged up. It sounds like you may not be driving the car sufficiently.
Good suggestion made about checking the current draw with a multimeter. However, If you don't have one... you could just disconnect the battery (ground) and then let it sit for the obligatory 3-4 days, reconnect and see if it starts. If is doesn't start...battery issue. If it does start, you've got an excessive parasitic load on the battery. I agree with the earlier post about checking lights that are in the ON position, etc.
Any aftermarket or 3rd party electronics installed? Do you use the radio or other accessories with the car in ACC (not ON/Ready)?
