Strange Red Triangle Behavior

You need to have the 12 volt low tested they can do this at Menards or advance Auto with the battery sitting in the car You need to take the plastic tray up so they have access to get to the battery Don't do this all up front at the charge points or the jump point at the battery always You need to find out if your battery can pass a load test and then maybe you'll flip the car on and see what your inverter's putting to the battery when it's supposed to be charging the battery 13.5 on up to a maximum of probably 14.5 and all that before you go any further you have to have somebody that knows what they're doing confirm that you're 12 volt is up to snuff not 11.5 volt not 11.7 12 volt is up to snuff and is capable of powering the computers the headlights and the stuff it needs to doesn't matter if it was replaced a year ago. You need to know now because -10 and 20 is nothing to play around in.

 

Buy a digital voltmeter (they are inexpensive) and learn how to use it. If your 12v Battery voltage is low (< 10v) it will not be able to run the pumps and initialize the computers and you will see the symptoms that you wrote about. A charged 12v battery will be over 12v and the battery voltage when your Prius is ready to run will be about 14v (slowly charging the 12v battery).

JeffD

 

The dash lights mean there's an error code that's been stored that will tell you what the problem is... Just guessing at the problem is not as effective as knowing the exact problem. You really gonna spend all that money on a new 12v when you don't know if that will fix it? Maybe charge up the 12v while you buy one of these devices to read the error codes with your phone and an appropriate app: Hybrid battery diagnostic and repair tool for Toyota and Lexus

 

If you don't drive the car very often, the battery will "self discharge" very slowly over time, there is a tiny "phantom drain" from the car AND the extreme cold will further temporarily reduce the capacity too.

So you probably need to fully change the battery manually, at the very least, and consider attaching a battery tender when not driven for more than 2 weeks at a time, or only for short trips over any period of time.

BUT.....your symptoms also sound like a bad connection on the main battery cables, which can get worse with cold too.
The negative cable connection to the frame/body is often trouble.

So, get your battery charged and tested. The longer you leave it low, the more it will be damaged.
And get those cables checked; BOTH ends.

 

yes, it is normal. drive it and see if anything comes back. hopefully, the battery was the problem.

even though it tested okay, keep your eye on it, it may not be.

 

If it need to be charged, a couple of hours on a trickle charge isn't going to do it.

It should be left charging until the charge cycle completes and will likely take something like 18 to 24 hours if it was close to fully flat.

 

NO. See my post #5 above.
And.....sometimes batteries test "good" when they aren't really.

P.S. No battery store uses a "trickle charger"........for anything.

 

I guess one could perceive these things as oddities if they did not know to expect them.

 

Just replace the battery to be safe and avoid getting stuck somewhere

 

Yes.
Sometimes it costs MORE to try and "do it yourself".
Often the fee for a diagnosis is money well spent. Sometimes not.

For instance, having the oil just a bit high on the dipstick is not likely to be the cause of the oil light coming on.......especially after it has been like that for 5 months with no apparent problem.

I kind of hate to mention this but.......if the oil level is actually going UP, that could be a blown head gasket.

 

You say that you replaced the 12v battery one year ago. Did you buy it at NAPA or someplace else? You have a warranty on the battery if it turns out to be the problem.

Take a look at post #3. Do you have a digital volt meter? If not, you should buy one and check your 12v battery when the car has been off for 12 hours.

When the car is turned on, the 12v battery is slowly charged from the high voltage (traction) battery. If you only drive the car a few times each week and for short drives, the 12v battery does not get fully charged. Also, the longer the car sits unused, the 12v battery will decrease in voltage. Once your voltage drops too low, your car will not go into "ready" when you step on the brake pedal, and you will not be able to start the car. So, it it a good idea to have a digital volt meter to check the state of your battery.

If you do not drive the car very much and have access to 120v, you should buy a good trickle charger and connect it to your 12v battery (at the battery in the back OR at the fuse box in front under the hood). Then you will not have any problems with the 12v battery getting low and the car not starting.

Posted via the PriusChat mobile app.

 

Just measure the battery voltage in the morning to determine the state of charge of the battery. More testing can be done later.

What is your normal driving pattern? How many days each week do you drive the car, and how long are the drives? How many days does the car sit unused between drives?





Posted via the PriusChat mobile app.

 

2 to 4 miles of driving in the winter is not enough to charge the 12v battery. So over time, the 12v battery is draining down and will need to be charged. I assume the battery that you bought one year ago was the recommended AGM battery equivalent to the OEM battery. I am guessing that your battery is still good, but you should charge it a minimum of one time each week during the winter.

Posted via the PriusChat mobile app.

 

Just to be clear, when you checked the oil, did you wait five minutes or more, remove the dipstick, wipe it clean with a rag, reinsert the dipstick, remove it again, and then look to see where the oil came up to on the dipstick?

 

Recently, in the second half of the year 2022, I did not drive my Prius for 4 months and left the battery hooked back in the hatchback. I did not disconnect the battery and put it on a trickle charge, for the 4-month period I did not drive the Prius. As I wasn't driving the Prius and some components, even if the car was not driven, consume power, the battery was dead after 4 months, as expected. One day when I decided to reuse the Prius, I jumpstarted the Prius, drove it and parked it in my garage, left it overnight with the engine on in the parking mode in my garage, and was able to bring the 12 volt battery back to life. By starting and leaving the Prius in parking mode overnight, I do not think it even consumed half a gallon of gas.

I read somewhere that the Prius, when the engine is on and running, manages to recharge the battery itself. You do not have to drive for the Prius to charge the 12 volt battery. As long as the Prius's engine is on and running and you leave it in parking mode, it recharges the battery. It worked for me, and that was how I brought back my Prius's dead 12 volt battery back to life. After bringing the dead battery to life, I took it to Auto Zone and have the battery tested. The battery passed the test and looked good. I am still driving my Prius using the same 12 volt battery.

In my experience, harsh winters do have an affect on a Prius 12 volt battery, especially if the battery was used for 2 or 3 years. The dead battery that I said I brought back to life was not able to start my Prius on the mornings of a couple of days this winter, when it was extremely cold, and I had to jumpstart the Prius. The same battery was able to start the Prius when temperatures were higher the very next day, without any issue.

A relatively new battery, i.e., a battery that was used for about an year or less than a year, should be able to start Prius without an issue in harsh winters.

P.S. I bought an used Prius that came with an old battery. I have yet to replace my old 12 volt battery with a new battery, to have my own real experience and understanding of how the new battery functions and its capabilities in a Prius.