I parked my 2010 Gen III Prius (~66k miles) in my garage early December and head out to vacation. Today, four weeks later, I tried to start the car but it is completely dead. I tried jump starting using my wife's Accord (left the Accord ON for 5 mins before jump starting) but that did not work either. I tried again a couple of more times reconnecting the cables but no luck. Nothing is on - no lights, etc. - What could be the problem - 12V battery or Hybrid battery? - Is it worth to try to reach the main 12V battery in the trunk and try jump starting from there? I have to first open the trunk though. If not, I guess I have to tow the car to a dealer. - If I have to tow the car, my car is parked front facing into the garage. Any tips on how the tow truck can get the car out for towing? Thanks.
Could it be the jumper cables are only "hot" on one side of the jaw? Some are like that. The jumpstart terminal in the underhood fuse box is plastic on one side, copper on the other. So look closely at your jumper cable, make sure the side the wire runs to is touching the copper side of the terminal. And you have a solid ground point, bare, substantial metal on the engine or body? I like a point relatively close to the fuse box: The jumper cables are solid too? And the Accord starts ok? It's actually odd that jumpstart is not working, sympomatic of problems beyond the 12 volt. But I would try one more time anyway, with the above, unless you've already cover all of it, are sure it's not an issue.
This is a multi part problem that can get complicated with a Prius. Perhaps the simplest thing to consider is putting a battery charger on the 12volt battery for 24 hours and then see what happens.
@Mendel: I noticed that the jump start terminal is plain on one side and with teeth/jaws on the other as illustrated in the manual but both sides looked like metal. Let me take a closer look at the jumper cable and I will try once more as you suggest. Do you think I can even try connecting the cable only on the side with the jaws(metal)? Negative connection just behind the fuse box on the nut. Accord starts fine, no issues. I have never had issues before with starting although never left the car parked this long (2 weeks was the most I had left before)
I suspect your jumper cables is not making a good negative ground contact. You only need a little power to get the Prius started. If the cables are connected properly, your lights would be working. So turn on your headlights while you're connecting the cables. If you see the lights go on, then it's connected properly.
12v might be fried. if that's the case, you'll have to climb in back and disconnect the neg lead to take it out of the circuit, then try jumping again.
@Mendel: Tried again and ..it worked. As you said, I connected the "hot" side of the cable to the plain metal side (this was clearly the metal side when I observed using torch light; the side with the jaws/teeth appears to be the plastic side) of the jump start start terminal. There was a shudder when I initially started with the Accord still ON - I pressed the Accessory switch first, then the power switch and then started. I suspect the shudder may have been due to not enough juice even tho' I left the Accord running at higher rpm for 5 mins. There was another shudder when I removed the jump start cables but again the engine held ON. I drove now for about half an hr (more than 10 miles on the freeway) and it appears fine. Hope it will start tmrw when I head back to work! Thanks much for your tip. @JC91006-As you said, the lights came ON even before I started the Prius when I connected the cables correctly. Thanks all for your feedback.
If it's your original 12v battery you're due for a new one. Driving 10 miles won't charge a dead battery that showed zero life previously. Be prepared to jump it again. FYI, the Prius takes very little power to "jump" since there's no starter motor. You don't need to run your donor car when jumping the Prius.
Yeah until you thoroughly recharge with a charger and/or replace the battery, it'll be low on charge, keep the booster cables in the car. A jump pack even better.
At the least, I'd recommend a day or so on a trickle charger. Mine has a pair of little LEDs that change color when it's done. As others mentioned, the 12V battery could be done for, but it's worth a try to get it charged back up as long as you're not concerned with getting stranded.
Most trickle chargers don't have enough amps to charge a dead battery. They're meant to top up batteries, not save them from a very low charge state.
Check the date manufactured label on your 12v battery. If it's the original battery, it's time to look for a new one. We've replaced the battery on our 2011 after being stranded while doing errands one day.
Are there date codes, I mean: directly readable? IIRC Yuasa (at least) uses a coded number. And if you contact them they might translate it. Maybe just assume it's original, go from there.
