Is my traction battery going bad?

My better half also has that feeling, I am under some pressure even though there is nothing wrong with our battery right now. Those of us who are aware of the sudden death batt behavior perhaps become comfortable with it, but my wife is having trouble living with the idea that one day the car may die (throw a Red Triangle). Hope I am driving that day, and I hope it happens at a convenient time.

Anyway see my thread on Toyota Goodwill Warranty. You could try explaining to Toyota that you would like to do a preemptive replacement and see what they can offer. Keep in mind in your case, if you got the Red Triangle, I would bet full coverage by Toyota at 151k miles in a CARB state.

HV Battery Goodwill Warranty Listing - Toyota Prius USA | PriusChat

 

Wait a sec, that's Positive Crankcase Ventilation valve.

 

isn't that the pcv?

 

plugs should have been done at 120k. are you following the maintenance schedule, or just fixing things as they break? it could need a throttle cleaning, or pcv replacement. injectors might be clogged, and etc., or it could be your hybrid battery going south.

 

I did my plugs DIY at 135k miles. The iridium tip is amazing stuff, I hate to think about throwing away the plugs with the itidium on there. The main thing is the plugs are hard to get out after waiting so long. I did not notice a big difference.

 

Dealers just do not care enough about your problem. Their only problem is how to get some or more of your money. The charge and discharge test I described is a variation of what can be found in the official Toyota service manual. If the technician had followed the book he would have done a very similar test. The results could have shown a weak battery that has not yet reached the threshold of throwing a code. They missed an opportunity to get more of your money. They could have charged more for doing a proper test and most likely sold you a battery.

I understand your position of placing a value on reliability. I rebuild batteries. For me it is easy. For most it is scary and expense. Every time I drive one of my Prius across country I have a few battery modules and the hand full of tools needed to swap one out. That could make the difference between being totally stuck and a couple of hours repair. For you that same level of security could require the replacement of the HV battery before it is completely dead.

Owning a Mini VCI cable puts you in a position of knowledge. It does not mean you have to do your own repairs, but that you will know what needs to be repaired. The cost is less than half of what you spent at the dealer today.

In the last year I have replaced two failed battery ECU's. They do fail and can be difficult to diagnose. It can seem like the battery modules are failing. A new battery from Toyota does not include the ECU. Some dealers will recommend a new ECU with the new modules. Those are dealers who have learned how to get more of your money.

Brad

 

43 MPG by itself is not good, but the car does not even warm up until 10-minutes, so not too shabby for a cold car. Also what I look for is not trip MPG, but if you start hitting 50+ MPG segments on a straight away after warm-up, then I think the Prius is working OK.

 

^^ Have you logged your battery module voltages while driving ?
I presume you have already excluded a weak 12v battery.

 

Yes

 

It's definitely worth checking it though. It will have something of a "threshold" type behavior, as in it will reach a point where it will suddenly try to use the HV battery much less because of the temperature.

 

Run the charge and discharge test without The Mini VCI cable and Techstream. A good battery can take 5 minutes to go from full green bars to a couple of blue bars. A weak battery could do that in just a minute. That is not a very accurate measurement but it is something to do while waiting for the cable.

Brad

 

and double-check the 12v just for funnies, it's cheap and easy.

 

Reporting a drop in fuel economy should be followed by a reasonably standardized test we can relate to:

1. Warm engine
2. Happy SOC range - about 5 bars
3. 5 mile to, 5 mile back trip at 60 MPH
4. No braking
5. Little wind

Before the test check tyre pressures, engine air filter, and hand brake.

A healthy Prius manages around 60 MPG

 

A very weak 12v battery pulls heavy current from the 12v bus while you are in Ready Mode and dissipates the energy as heat.

JeffD

 

what he said. ^^^