I'm having battery issues...

With strange electrical issues in the Prius always suspect the 12V until it is eliminated as a possibility. Check the 12V voltage after it has sit for some hours, overnight for example. Weird stuff happening? MPGs dropping? Test The Battery | PriusChat

 

how many miles on her?

 

The main symptoms are seeing the battery SOC on the info screen go from very low to very high and back again in short intervals, poor MPG and engine running more often, and hearing the battery cooling fan come on. This is usually followed soon after by DTC's being set. If you are not seeing any DTC's, then the Toyota tech will just say all is well.

 

Is it under warranty? Free?

 

SOC= State of Charge, i.e. the battery indicator on the screen.

DTC= Diagnostic Trouble Code, or simply Codes, the computer output from the various controllers that indicate what's going on beyond the dashboard lights.

 

No, it's just the essential first step in diagnosis, and something the dealership will not necessarily get right. It's painless to do, and too many problems are cleared up with a new 12V battery to not get that out of the way first thing. But as already mentioned, without the codes listed, no one can know for sure.

In any case, if they give you a new HV battery for free, go for it, definitely.

 

congrats! how many miles on her?

 

ouch, thanks! all the best with your new cells!

 

Hey all,

I have a 2006 and sadly am having the same issue, except sadly I am long off warranty, as I am up to 272K KM (~ 170K miles). Here's my story, sorry if it is a bit long, but I think it's good to share for everyone's benefit.

The suspicious activity started about 3-4 weeks ago when I noticed the same behaviour the OP mentioned, where the SOC would fluctuate very rapidly from very low (1 bar) to very high (10 bars), even in the span of a mile or two, on flat ground and cruising. After driving the car for 7 years, it's not hard to tell that is not normal.

It did that a few times over a couple days, yet my fuel economy seemed much better than it had been in a while, but it may have also been coincidence with the warmer spring weather.

Anyway, finally two weeks ago the "Christmas tree" lit up, as in the picture above (car with exclamation at top of screen, the red triangle, Check Engine light, along with VSC light and the (!) light all came on.

Took the car to the dealer and hooked up the ODB2 scanner which kicked out a P3000 code (Battery Control System) and P0A80 (Replace Hybrid Battery Pack). The report indicates that Battery Block 12 is reporting a low voltage and needs to be replaced. See attached report.

One of the techs told me that the battery modules can be replaced individually, but they have not been able to get a part number or price from Toyota (?). They did have a part & price on the entire pack, around $3K.

The tech told me the car fell into "Fail Safe" mode, and should be OK to drive in the meantime. When I left the dealer the triangle and Check Engine and icon at the top of the screen remained on, but the others shut off, and the car drove "OK" for the most part, though the acceleration was noticeably jerky. After about the 3rd day, the other lights came back on, and battery fan began blowing constantly and the engine almost never shut down. And of course my fuel economy predictably took a huge nose dive.

By about the one week mark, a new behaviour began to appear, which was losing virtually all torque and the engine revving at a high rate. Felt like it was about 3000 RPM, though I don't have ScanGauge to confirm. It's also worth noting that NO other lights or messages appeared, except that the Energy Monitor showed NO energy going to or from the battery despite whether I was accelerating, coasting or stopped. Clearly, the HSD had decided to disable the battery and I was running solely on the ICE. Not fun. If you've driven stick, imagine accelerating from a stop in 3rd gear, that's what it felt like.

Anyway, the first time it happened I was on the highway and was hesitant to stop as I didn't know if would start up again. I eventually got off the highway, pulled onto the shoulder and as the engine continued to rev I hit the power button and waited about 3-4 seconds for the engine to spin down (!). Crossed my fingers and powered her up again, and she was back to her "new" normal, with the Christmas lights and jerky acceleration, but at least I have some torque again.

The next day it, happened 3 more times on my 40 minute commute home, and again the following day in my first 5 minutes of driving, so I decided to turn around an leave it parked in the driveway for now until I can resolve the battery issue, and drive my wife's Kia in the meantime. :-/

In any case, back to the dealers. I did contacted two other dealers who said the same thing, though once of them offered me a considerably better deal (and happens to be the dealer from which I bought the car, though it is considerably further from home) at a total price of C$2855, including labour and taxes.

It's obviously a lot of cash for a car of this age, but I don't currently have the budget to afford a new car (kids!), and the car is otherwise in great condition. The way I see it is that I am screwed either way, as even if I decide to sell or trade it, I am taking a hit on the condition anyway, so may as well get it fixed and get more life out of it.

Therefore, my decision now is whether to go for the brand new pack as quoted, or take a chance on a pack from a scrapyard (which one dealer had located for $1200 + ~$300 labour), or try to find a place that will rebuild my own battery, which I have not been able to find so far.

Does anyone know of any Canadian battery rebuilders, near the Toronto area?

Big decision to make, and am leaning toward the new pack for the $2855 price, but thought I would throw it out there for opinions...

Thanks.

(PS - I've always been a big hybrid advocate, and while this is also discouraging and is the first real chink in the hybrid armour, I still love the car and the technology and still remain far ahead in terms of money saved on gas vs repairs. I just seem really unlucky, as battery failures still seem very rare of Gen II+ HSD.... )

 

Thanks sharing your experience Sarge. I guess it depends on how long you plan on keeping the car. If you want to drive it till at least 500k kms then why not buy a new one. Though, you might get lucky with a used one a be able to drive it the same length? Here in B.C. the used batteries are hard to come by because the taxi drivers pick them up pretty fast. I've seen them going for as little as 500 bucks in the States on ebay, and if you can have it delivered to a postal outlet across the border and then pick up you could get it free delivery usually, you could save a bundle especially if you put it in yourself....

Did you check the 12 v battery condition?

 

Hi Dino33ca,

Thanks for the reply. I have been debating whether it is worth going with a rebuild/used cell or battery pack vs new. I would like to keep the car as long as possible (as long as repairs remains more cost effective than a car payment), which is a reason why I was thinking the new battery pack may be the safest option.

I don't feel comfortable doing the work myself, I would rather pay someone who knows what they are doing. Unfortunately I have not found any aftermarket shops within my area.

I think the main question I am looking for feedback is whether replacing a cell in my battery pack would be wise, or am I just delaying another inevitable failure in another module? The car has never been abused (i.e. never run out of gas or let the battery reach extremely low charge by leaving in Neutral, etc.). Of course, I hope I have not done any further damage with the extra driving I have done since it was in fail safe mode, since it has been disengaging the battery more frequently lately.

Anyway, the 12V battery is a good suggestion - it is still the original. I will make sure that is checked as well, but the diagnostic report clearly showed an issue with one of the HV battery modules too.

Thanks again for the reply.

 

How many miles on the battery?

 

He mentioned 170K miles above, but mileage is less important than age. A 2006 lead acid battery is well past retirement age. Replace that pronto and then see what happens!