I have a 2010 Prius. Recently bought used from a dealer. How long should the hybrid battery last while siting idle? I want to know if the battery is going bad as it's still under warranty, but I don't trust the dealer to give me an honest answer right now.
congrats and welcome! the longer it sits idle, the worse it is for it. but no one can predict how long a battery will last, idle or active. that's why you have a 10 year/150,000 mile warranty. you can't get warranty unless the red triangle on the dash lights up, and the trouble code associated with it is a bad battery. why is it sitting? prius like to be driven. how many miles on her?
Are you asking about leaving the car parked unused for a long period, or about how long it can stay in READY mode before the engine must restart to recharge the battery? In the former case, the 12-volt battery will die long before the big battery does.
As bisco says, you're not going to get a warranty claim unless the battery fails spectacularly with triangles, lights and warnings. What's more likely is the older battery will simply not hold a charge as well as a newer battery. The car is completely drivable in this condition and will be for years. What you will notice is the battery meter/gauge (state of charge, SOC) will fill and empty rapidly. It will fill rapidly when coasting downhill and it will empty rapidly when climbing a hill. If you find yourself coasting down long hills with a full battery, you will want to become familiar with B mode (engine braking) to save your friction brakes. If you find yourself climbing long hills with an empty battery, you will experience the combustion engine revving loudly as it will be the only power source, and you will likely be unable to maintain higher speeds during climbs.
Congratulations on your new purchase! Hopefully you get many years of enjoyable driving. My sister has a 2010 as well. Beware of oil consumption. Definitely check the oil every 1000 miles till you know how much it burns. If it doesn't burn any now it will. My sister has 256k on the hybrid battery and it still has plenty capacity, charging and discharging slowly. It's amazing how well these batteries last.
It sounds like you're asking about the general health of your traction battery. Finding out will cost you around $16. First, go to eBay or Amazon and buy an $11 OBDII reader with Bluetooth. Pair it with your smartphone. It will show you a bunch of details about your car. Next, go to your smartphone's app Play Store and buy an app called Torque Pro. It's $5, but a free version is stripped down to fewer features. There are YouTube videos that will show you how to set it up, add voltmeters, etc. One of the features of the paid version shows you the voltage (down to 1/10 volt) for each of the 14 individual cells in the traction battery. My '05 Prius has all the cells within 1/10 volt of each other. If you find one that is quite different from the others, keep an eye on it over time. If it turns out badly, you would have that cell replaced, not the entire pack. Unfortunately, you cannot swap a cell without disassembling the entire pack from the car. If you find a number of cells are flaky, your future is looking dim. Some people may argue that I'm full of s___t, and that you should not repair an old battery pack, since it could be unreliable, etc. If nothing else, you may find that your $16 has bought you a ton of relief and learn that your battery is fine. Or, it may give you some recourse to bargain with the dealer. Since the OBDII adapter just plugs in under your dash, you could also connect it to other, similar cars and see if your results are similar. I would unplug it when you turn the car off, unless you want to do further tests with the engine shut off. As another poster said, the best way to keep a hybrid in good shape is to drive it. Letting it sit for long periods is not a good plan. If you do have to leave it for a while, turn off the Smart Key feature. My Prius has a pushbutton under the steering wheel to disable it. My wife's Camry hybrid does not have any way to turn off the Smart Key. Also, do not store the Smart Key near the car (e.g., in the glove box, on the dashboard), as that slowly drains the 12-volt battery. The 12-volt AGM batteries are pricey. When we go out of town for extended periods, I put a trickle charger on mine (around $10-$20).
If you use the digital display gauge, you can long press on the display and configure it for more display digits.
I agree with the downhill part of that, but consuming battery charge on long climbs is clearly NOT the way my Prius behaves, except when the charge indicator starts with more than six segments. In fact, it will increase to six on a sufficiently long hill if it starts with fewer. This is in ECO mode. I'm afraid downhills or frequent braking do bring my SOC display from six to seven segments a little quicker than it once did.
The OP was asking how to tell if a battery was bad. I was writing about my experience for the behavior of an old, degraded battery on Colorado hills in our 2005 with 145K miles.
Perhaps second-generation Prii behave differently in that regard? Anyway, uphills, including long ones, normally seem to have have no significant effect on charge level in my third generation. Braking, or getting stuck in slow traffic (or stoplights, etc.) definitely changes SOC.
The Prius makes a bad car to snowbird; if it sits idle for 6 months a year, it will not last long. As folks point out, you do not actually have to drive it, if a friend starts it and runs it in their driveway an hour a week, it will stay much healthier. It won't use much gas in the driveway. If none of us answered the question you tried to ask, rephrase it and we will try again! (Prius taxis can last a quarter to half a million miles as they never sit, turned off)
