Bought a used 2012 Prius Two. How can I tell if the battery is okay?

It sounds fine. It's unusual for the hybrid battery to show fully charged, typically it'll only happen with a long downhill run. And even then, it's showing full but I believe it's something like 80%. If the state of charge goes up and down, and is occasionally one bar from the top, that's very normal.

Same for the 12 volt, likely ok. 12.5 volt is slightly low, but there's a lot of variables, the car's display for one. When I measure our 12 volt with a digital multimeter, it's read between 12.5 and 12.8. You could try periodically hooking up a low amperage smart charger, leave it on overnight. I'm using a CTEK 3300 for that purpose, it's a little dated, and I think there's a lot of brands that do similar. It shouldn't be high amperage, 4 amp is good.

 

.......the top line never lights up. It'll get 7/8ths full, though
This shows the charge level of the large battery that assists in propelling the car; it rarely shows full(lights all the way to the top) the number of "bars" that are lighted may vary widely during your driving experience...
There is another smaller battery that is used to power/activate the (for a better word)starting system.. The dash battery icon/indicator has nothing to do with this smaller battery..
.........In 'Vehicle Signal Check Mode' I saw 12.5V with the car off and 14.3V when I turned the engine on
This is indicating the condition of this smaller battery and appears to be normal...

From what you have described; the indicators show your car is performing properly...
Make certain all lights/interior and for that matter exterior lights are off after shutting down the car; if not the "smaller battery" may be drained to the point it can NOT power/activate the starting system..

 

Umm why wouldn't their be a warranty? Toyota gives you 100k warranty on a lot of hybrid parts including the battery. I didn't think it mattered who has the car it still has a warranty. You still should have the 60k warranty that covers the powertrain and seatbelts and airbags.

 

I agree with what Mendel and CLUBGUY above said. The traction battery (big battery) sounds like it is fine. Your 12 volt sounds a little weak, but is probably good for a couple more years PROVIDED it has NEVER been run down. You might want to study ALL of the links found in my signature below. That will help you IF you are interested in obtaining maximum miles per gallon and top efficiency.

I too recommend you get a good smart battery charger/maintainer and hook it up at least once a month. That will keep the 12 volt fully charged.

In my opinion, you bought the best car money can buy on this planet at this time. Your car is still covered under warranty through Toyota for several things including the traction battery, exhaust emission controls, inverter, and all hybrid parts along with body panel rust through.

You can sign up on the owners website for Toyota and register the VIN of your vehicle. Once you do that, you will have a good idea of what has been done to your car. And what needs to be done. Keep the maintenance up and don't forget to check ALL of the fluid levels at every fill up. When checking the oil, it is BEST to keep the oil in the engine BELOW the full mark, but way above the LOW mark. The difference between the two marks is 1.6 quarts. The Prius engine is full of oil when you change the filter IF you only use 3.9 quarts. Do not overfill the engine. Stick with the "synthetic" oils and use the 0W-20 oil when doing the oil changes. Don't forget to install a new filter when you do the oil changes. The maintenance light will flash 500 miles before EACH 5000 mile interval. At each 5000 mile interval the maintenance light will then glow steadily. Depending on how you use the car, you would then have the tires rotated, and based on usage change the motor oil and filter. Toyota recommends changing the oil and filter once every 10,000 miles provided you do not enter what is known as "severe service". Read your owner's manual. You will find that more than likely at least one of your driving habits will fall into "severe service". Therefore it is a good idea to go ahead and change the oil and filter every 5000 miles. Keep an eye on ALL fluid levels at all times. Replenish as needed. The Prius uses Toyota "Super Long Life Coolant". AKA Toyota SLLC. Both the inverter and the radiator use the same fluid. (Toyota SLLC). The fluid comes premixed, so do not add any water to the fluid. Just pour it straight in. A good funnel is helpful for these fluids. The transaxle uses Toyota WS Fluid. At 60K, and every 60K interval after that it is recommended by many here on PC to drain and refill the transaxle. It takes four quarts of the Toyota WS fluid to do the service. A flush is NOT required. All that is needed is a drain and refill plus the replacement of two crush washers. The only way to check the fluid level in the transaxle is to raise up the car and remove the fill plug. It should be full to the bottom of the plug. Most don't check it, just drain and refill. Any local Toyota dealer can do the service work for you. Find one you trust and give them a chance. If they don't please you, take your business elsewhere. I don't recommend these quick oil change services. Either DIY or take it to Toyota. Other than oil changes, tire rotations, and keeping the fluids full you won't have to do anything else until 100K miles. Make sure you use the correct oil and filter. I recommend the OEM filter. When doing oil changes, change the crush washer also. Gen III Prius uses a cartridge rather than a spin on filter. It can get messy at times, so you might want to let Toyota do it for you also. Again IMO you got the best car on the planet. Take care of it, and it will take care of you. Learn how to hyper mile. Remember the Prius is unlike any other car you have ever driven. It will take some time to learn everything, and even longer to master it all.

The little 12 volt will probably last about four years. Little to no warning will be given before it fails. Except for funny things to start happening with the Prius. When you need a new battery, make sure you use the correct one. I recommend the OEM battery. Other's will recommend different brands. The main thing is to get a AGM type battery that fits properly, vents properly, and has the reversed JIS posts.



Finally "Welcome to Prius Chat!"

Best of luck to you,
Ron (dorunron)

 

Exactly. Well said.

 

Welcome to PriusChat! I hope you enjoy your Prius as much as I have enjoyed mine.

Here is the Warranty and Maintenance Manual for a 2012 Prius http://www.toyota.com/t3Portal/document/omms/T-MMS-12Prius/pdf/2012_Toyota_Prius_WMG.pdf

As you will have noticed, we tend to over document what you need versus leaving you in the dark. Take what information you want, we have more. In any case, step one is "Just drive it". Get comfortable with the seats, instruments and mirrors/sight lines. Once you feel like a safe driver, there is plenty of time to be a frugal driver.

If you think of the big battery as where braking energy is stored, you can see why you don't want it to fill up. (There is actually an engine braking system if it does, but that does not reclaim energy like the battery. If you visit Colorado, expect 'new' and alarming engine noises)

 

Florida doesn't have any mountain descents tall enough to get that top bar lit up through normal driving.

 

Your car is only two years old. I wouldn't worry about it. Your warranty should cover you just in case.

 

If you do not have an owners manual get one. Once you have one read it cover to cover. That will answer some of your questions. I would avoid going into the special screens and maintenance areas as you could cause some damage if you change settings inadvertently.

From what has been described, all sounds normal.

 

Here is the Owners manual, (chopped into chapters) also if you register your VIN, you can see all Toyota services done to your car.

Toyota Online Owners Manuals and Warranty

 

bestmapman did raise a good point. Be real careful messing around with the screens on your Prius. I messed with mine, and inadvertently wiped the memory of all my navigation points that I had stored in the system. I was trying to adjust the microphone volume level as one of my friends complained he could not hear me. I checked with Toyota, and indeed there is an adjustment for it, but on the 2013 that I own, it is only adjustable with the Tech Stream Software that Toyota uses.

And Jimbo is also correct. Get used to the Prius then you can learn the finer points. That is why I said it will take you about a year to figure everything out, and then a long time after that to master it. Some days it becomes a game for me, other's I just drive it. It is all about my mood, the time I have out there on the road, and what the traffic is like at that moment.

Enjoy your new to you Prius and don't worry about. Remember it is the best car on the road IMO.

Ron

PS I am on my second one. That should tell you something...

 

Welcome to the forum. Feel free to ask any questions you have however ridiculous you may feel they are.

I think others have covered everything. Your 12v should be fine. Your HV battery will only get 8/8 after a long decent.Try not to block or cover the vent on the back seat and let your passengers know that too. Don't try to keep the car on electric, just drive it and enjoy - you'll love the silent, smooth ride.

Enjoy.

 

Pay attention to what that British Cabbie just said about the vent in the back seat. Keep it clear at all times, and clean too. Don't let anyone or anything block it. Also, if you carry dogs or cats in your car be aware that the fur can get into the battery cooling system via that vent. It is important to keep that system clean. Otherwise the battery will overheat and shorten the longevity of it.

Again best of luck to you. And enjoy that new to you Prius.

Ron

 

I have a new 2013 Prius III, I only saw the top top bar charged upon going down a long hill with no daylight or fan on (means nothing was draining the charge)... however, I think the best way to know if the battery is okay if the car makes good MPG like 49 and up on trips that are 6 miles and up in normal weather... I made 54 MPG on a 166 miles trip from North Jersey to PA at speed between 72 and 75 MPH. My normal work commutes (11 to 12 miles one way) I can make between 56 and 70 MPG. It's a good commuter car. I monitor the wheels closely for 20 degree weather changes keeps them @ 36 PSI front and 35 rear.

 

The computer will take care of your battery when it needs charging. Just drive your car and don't be concerned about it.

 

I drive up to 300 miles a day in NYC and the greater NY area, The only time the top bar is filled in is when on way home I have to go down a very steep long hill when i get to the bottom it lights up top bar, Another note of interest is a weak battery will charge up faster as it usually has a poorly functioning or dead cell that will not recieve a charge so if your battery was to fill to the top easily under normal driving conditions I would be concerned.The prius is a great car no doubt. this is my second one.