Bought a 2006 w/ 87k miles, might have P0A80 issues already

Having recently gone through a steep learning curve with all things Prius battery related after my 12v died, and now with my hv fully assessed and showing only 40-50% life, I think you should first find out what the state of the hv is...get the codes, share them here. If I sound like I'm projecting, I am. I can't stress how much of a one-step-at-a-time approach is going to keep you calm. First things first. If A, then B. If not A, then Z.

Whether it sucks or not, it still needs initial assessment. CARB state or nor CARB state, find out first what the hv battery is doing (or not doing), then If A, then B; if not A, then...

However you go about your solution (dealership help, reman, brand new, with or w/o a DIY install), take this an opportunity to learn a baseline for your car. It's a different kind of car ownership and it's kinda cool to see where this technology differs from anything you've ever driven before. And, just like many forums, this one has it's share of hardcore enthusiasts, experts, novices, and everything else in-between (even some voices that sound like they also double as CraigList rant trolls). Pick and chose. Enjoy. Learn. Revel...you get 45+ mpg on a bad day!

 

yes, 12.2 is terrible, replace it before looking before chasing for ghosts.

 

> If you're talking about the state of charge on the MFD, there's been nothing abnormal at all. The battery indicator has never fallen below 5 bars.

Just a heads up...my SOC on the MFD showed an steady increase in charge up to 8 blue bars on my way to get the battery assessed: city streets, 35-45 mph depending on zone, and steady slight incline. The erratic SOC that I witnessed was on highway driving: 55-65 mph for about 50 miles, some hills. On a steady decline, SOC showed only one pink bar and didn't move up during the entire descent.

 

@bisco
> yes, 12.2 is terrible, replace it before looking before chasing for ghosts.

but 12.2 is before starting the car...? don't step on brake, press start, hit display, and get to the screen that shows readings...12.2 isn't bad, right? if you then step on the brake and start the car, the volts should show 14.2 or higher...?

 

They are not allowed by law, at least this is what I was told in Advanced.

with respect to 12v bat the easiest way to check is to connect voltmeter, and then turn car on but not to ready so engine doesn't start. If battery is bad you'll see voltage dropping quickly below 12v.

Also it maybe not bad idea to invest into torque or engine link. Torque is $5 (link is $7), there is a free version also, and generic OBDII bluetooth plug ~20$. Just beware that if you are iPhone user, Engine Link needs a specific WiFi plug which is more expensive.

When my Gen3 was hooked up we took it for a ride, and the information available on OBDII included max voltage diff btw modules, which changed under the load.

Traction battery can be rebuild/re-balance, there are numerous instruction/videos on net, for example:
Rebuilding a Hybrid Vehicle Battery Pack | Home Power Magazine

If you don't feel like DIY, you can have someone to do it good luck

 

the 12.2 should be at least 12.5. get a new battery. don't think of it as a 12 volt battery, think of it as a 13 volt. that's the new voltage. mine is 12.7 after sitting overnight, it's almost 3 years old.

 

In my opinion, it is highly likely that you had a weak 12V battery causing your problem/warning lights/DTC's. The fact that the DTC's have not come back is a very good sign. When a Prius sits on the car lot, the 12V battery slowly discharges. A test drive will not charge it adequately and it will get worse and worse with more test drives. Additionally, the fact that you were able to get 47 mpg tells me your car is fine. These cars love to be driven regularly and when they are not, you get things like this happening. I think the car will be fine.

 

Fingers crossed!! Tell us what you find out.

 

I recommend you get a Mini VCI cable and TechStream software. Every Prius owner should have this. There is a really simple test you can do yourself. Use TechStream to look at the live battery data. This will show the voltages of all 14 module pairs in real time. The static voltages will not tell the whole story. You need to put a drain and a charge on the battery. A "forced charge" is done with the car running in drive and the brake and gas fully applied. Your Prius will just sit still and charge the battery. Give it about thirty seconds. Record the voltages while under charge. Use a camera, print screen, or a helper. A discharge can be done with the car running in reverse and the gas and brake applied. It is best to have the car warmed up so the gas engine stays off. Apply enough gas to show a drain on the battery but not so much that the gas engine turns on. After about thirty seconds again record the voltages. In a perfect battery all the voltages will rise and fall together. Weak module pairs will have a wider voltage swing. In my experience a difference between module pairs of 1.2 to 1.3 volts will trip the error codes.

Brad

 

12.2 V is actually nearly flat. You need to charge up your battery overnight (12-15 hours) with a good modern smart battery charger and then let it rest for 4 hours. Measure the 12V battery voltage again. If it is not better than 12.7V you need to start shopping for a new battery. Given that you have said you got ~47-48 MPG, its possible that the battery is recovering now that you are driving it more than when it sat on the lot.

In addition to this, put the headlights on and monitor the voltage. If it quickly drops to under 11.8V, you need to replace it.

 

jeff652 is the one with real data on how well the grid charger works. Do a search for his posts, for example
HV battery maintenance suggestions | Page 2 | PriusChat

It would be better to do the balancing sooner rather than later.

It is not possible to know how well it will work on your particular car. Certainly Toyota will do nothing without a failed battery code showing. They don't concern themselves with the capacity, only what the car says is acceptable.

 

Yeah, I agree with nh70, A grid charger would be an excellent idea for you. But lets look at reality. Is it necessary, no, will it help, yes. If it were me, I'd buy a grid charger and do the balancing myself. Then periodically thereafter.