Prius C forum, Our 2012 Prius C Two has been parked in the garage at our summer home since Dec 1. I filled the tank and put in additive. I didn't disable the smart key system because my daughter goes by every every few weeks and starts it up, pulls it out of the garage and lets it run until the ICE stops. This should be enough to keep the "small" battery charged. Late last week the car started and immediately shut off and the fuel gauge was indicating the tank was empty. She added 2 1/2 gallons but it still wouldn't start. I called the dealer who came and towed it away. He called me today to say the battery is OK and they think the problem is the tank is empty. I told him that I can imagine someone somehow got into the garage and siphoned out all the gas but what happened to the 2 1/2 gallons she put in. I had him check and the gauge still indicated the tank was empty. He said maybe it wasn't enough to get the bladder functioning. They cleared all the codes, added 2 more gallons gas and the gas gauge read about 1/2 tank. Then it started. One of the service people suggested that maybe the car was left running and used up all the gas. This seems stupid since the ICE will stop when the "small" battery is charged. Also if it ran for days the house would be full of carbon monoxide. They didn't find a leak which I didn't suspect because the garage would have smelled like gas. Why was the gauge indicating an empty tank? Does the computer keep the ICE from starting if it thinks the tank is empty? What is going on here? jerryd
The bolded part is definitely NOT enough. I'm not sure if the Prius c uses the same tiny 12 volt as the Gen 2 and Gen 3 liftback (wouldn't be surprised if it's even smaller), but see 2005 Prius beeps when door is open, then won't start | PriusChat and Stall-out/Recall | PriusChat and Stall-out/Recall | PriusChat. Prius has no alternator. It doesn't matter if the engine's running or not. The 12 volt gets charged (unfortunately at a very slow rate) when the car is in READY mode. As for the bladder. I don't think the c has a bladder tank. That was only on US (and Canadian?) Gen 2 (04 to 09) Priuses. It was ditched on the Gen 3. I know on the Gen 2 Prius, if you add to small an amount of gas, it may not register. It's documented in the manual. As for your last part, yes, that could've happened. When the HV battery runs too low, the ICE will start back up to maintain the HV battery level, then stop... run low, start again, etc.
Just a suggestion why not fill the tank in the future and have her drive the car around town and get the car warmed up. A Prius works best if it runs everyday. Long periods of inactivity is not good for the battery and other components. Don't just start it but drive it at least 10 miles as often as possible.
The emissions are so low that it might not be noticeable if she left it running. That does seem the most likely happening. The engine will turn off and on to keep the coolant temp up and will eventually run out of gas. There are threads on running the Prius dry- you should probably search for them.
Why not just keep a battery tender on the 12V battery? If your daughter is willing to help out, have her actually drive the car to heat cycle it, but that only needs to be once every few weeks, or even once a month.
No offense because that scenario would be frustrating but the fact that this is labeled as a "first problem" and enough people are commenting and the complexity of the problem makes me laugh. These truly are well built and reliable cars with a only a couple little hitches.
I would probably just keep a battery tender on it and call it a day. no need to start it once in awhile, or what not. just make the tires are inflated and you'll be good to go.
Silly question but why is this car NOT being driven? What's the point of "storing" a car at a summer home; it makes NO sense. You can't store a car for long periods and expect it to run well. You might as well sell it or store it at your regular home where it will be more often driven. Honestly, who buys a car to drive only part of the year. You'd be better off doing a short-term lease when you're in your summer house. Not to be too critical but this is illogical.
