I've noticed that in the mornings the Prius will struggle to find the power to climb up the hill, and then see that the battery is low, around two bars. Then once I drive it a little, it goes back to normal. Is it time to start looking for a new one/doing a DIY repair on a bad cell or two? 12v was replaced a little more than a year ago.
it’s time to not worry abt it and wait til codes pop up. there is no predicting when your battery will fail. if you’ve got the time and money to replace the battery prematurely, then you could go that route too
If you're not already doing so, it would be best to let the vehicle warm up before climbing. Have you had a chance to balance or recondition the HV battery?
Batteries need to discharge and recharge it's like a life cycle thing it's how batteries live so if you spend a lot of time looking at your display in worrystion. Then that may be how you live. I don't know personally some people are just like that they spend a lot of time studying and then they study long and they may study wrong and it may cost them I would say enjoy and drive the pee pee out of your car and when you have some codes and things start happening then we start to address them worrying about your battery gauge going up and down is kind of a sort of senseless worry if you had other things that were less important that you monitored the battery on you would see similar things but those things aren't as important like headphones and you know whatever just other battery things. Good luck man
All points noted. I have a second vehicle so when it eventually happens I won't have much of a life interruption.
Mine followed that pattern and I'm currently servicing the battery because it failed. If you'd like a data point. I got about a year and a few months then it failed after it started that pattern. My mileage also dropped 4-8 mpg in the last 6 months.
I have 2 Gen2's. Both over 300k. One of them keeps strangely having a super low Traction/HV battery in the mornings. It's my wife's car, I've noticed it the last couple weekends. I mean I go to take off, I'm like man why is this so weak, then I see the battery indicator down to 1-2 bars. When it happened once or twice, I didn't think much, but it's happened several times now. I would assume something is draining it. My guess would be one of the 28 cartridge deals? But I don't know much about them?
Advance auto claims the 12volt battery tests as a good battery. Not sure if their tester is even designed for these batteries
Get an OBD2 dongle and a copy of Dr. Prius, measure the battery voltages the night before, and the next morning, and report back. (Note, only get one of the OBD2 pieces that is recommended, or it might not work.) Since you are in Michigan, is the car suddenly seeing extreme cold temperatures?
You can restore the capacity on these batteries with a grid charger and discharger, and these symptoms will go away, but since the batteries have over 300k miles on them, this will most likely have to be done every 12 months.
