HV Battery Failure.... please help

How good are you mechanically?

Prius battery, eBay Motors, Remanufactured. Great deals on eBay!

(One of the sellers actually will install it as well)

 

If you're getting a brand new HV battery for $2000.00 including labor, this is one hell of a good deal. This price must be subsidized by Toyota. The MSRP for the Gen II battery alone is close to $3000.00. You certainly can't buy much of a used car for $2000.00. And you could get another 145,000 miles out of you 2004 if you've taken care of it and continue to do so.

When the HV battery in my 2005 goes, I hope to get as good a deal.

Go for it and don't look back. Take care, Dan

 

Welcome, sciencekit,

Do you know if VA has become a Calif emissions state or not? I know the 6 New England states & NY, NJ, & CA already are, but I recently heard that a few new ones have been added. If VA is one of the new ones, then you will be able to just squeak in under the wire & get a free battery replacement because in the CARB (Calif Air Resources Board/Calif emissions) states, the hybrid components (includes high voltage/traction battery) warranty is 10 yrs/150,000 miles.

If VA is NOT one of the new states that allows the added time/miles on the hybrid component warranty, then if you've had your Prius serviced regularly by your dealer & you call the Toyota Customer Experience line (somebody else here may have their phone number handy), you may be able to get Toyota to help you out on the cost of the battery replacement.

You may indeed need a new high voltage battery, but before you go that route, tell us if you have ever had the little 12V battery replaced yet? I'll say as others before me have said that when a 12V gets near the end of its life, it can cause all kinds of crazy warnings & symptoms that the dealer might be mis-diagnosing as a failing high voltage battery. If you haven't had the 12V replaced yet & have the $150-$200 to do so, I would try that 1st to see if that cures the situation before spending the big bucks for the high voltage replacement.

Just a little personal example of how screwy electronics can cause a mis-diagnosis:
5-yr old TV stops working, FACTORY-authorized repair shop says microprocessor no good & NOT being made any more, manufacturer does world-wide search for microprocessor---none to be found, then they do a world-wide search for the whole circuit board with that microprocessor on it---also none to be found, repair shop's recommendation after one week with my TV set there:throw it out, but pay them for their diagnosis. I pay them $35, but want 2nd opinion from another FACTORY-authorized repair shop. 2nd shop tells me over phone that it's unusual for that microprocessor to fail. He doesn't think that's the problem at all, so get it back & bring it to him, because he's 99 % sure he can fix it without a replacement microprocessor.

I take it in to him & after only about one hour of working on it, he has it fixed. It wasn't the microprocessor at all, but just 6 little cheap transistors that were too weak to send signals strong enough for the microprocessor to do its job. Result:TV cheaply repaired (still had original microprocessor) & set keeps on working for another 5 years until replaced by HD set for the broadcaster's HD switchover last June.

Was told by 2nd shop that if 1st shop had done a step-by-step troubleshoot, they too would have found the problem. It was thought that they only did an end-of the-line hookup & diagnosis & found a weak output from the microprocessor, thus falsely blaming it when in fact the microprocessor was fine but having a difficult time dealing with the weak or non-existent signals coming from the 6 failing transistors.

The above example may be similar to your battery problem if you haven't already replaced your 12V one. Another cheap repair (if you do need a replacement high voltage battery) is to get a good one from a salvage yard (way cheaper than the $2,500-$2,000 the dealer will sell you a new one for).

Ken (in Bolton,Ct)

 

VA is not a CARB state.

Taking Ken's good advice a step further, I would get the diagnostic trouble codes from the dealer and post them here. The collective wisdom on PriusChat can help you make an informed decision, but being informed likely will require DTCs. PC member Patrick Wong in particular can be of help. If he doesn't chime in here, you might send him a PM.

I agree that if your HV battery has failed, a salvage battery is a viable and considerably less expensive option, assuming you can install it or find someone who can.

 

Thanks for obtaining the DTC. I assume that the code is P0A80, and the meaning of that is to replace the traction battery.

Since you are willing to DIY (I assume that you know how to work with high voltages), I recommend that you retrieve the car. When you get it back, disconnect the 12V battery negative terminal for several minutes to allow the DTC to reset. While the battery is disconnected, hook up a battery charger to see whether the battery needs to be charged.

After the 12V battery is charged, reconnect the 12V battery negative terminal. Take the car for a test drive and see if the same warning lights reappear. If yes, then I suggest you buy a salvage battery for ~$600 or so, consult eBay Motors or your local salvage yards. In principle, you should be able to install the salvage battery without having to charge it; obviously the later the model year that the battery is, the better of a choice it will be.

Then download the relevant repair manual pages at techinfo.toyota.com so that you can learn the details about how to remove/replace the traction battery without causing damage to yourself or the car. Once you have done that homework, if you have questions go ahead and post them. Good luck!

 

Sciencekit, as others have said, a weak 12V battery apparently causes some very squirrely symptoms. For example, a week ago my 2005 (5-1/2 years) would not power up. I merely heard a relay click when the Power button was pressed for On, then again when Power was pressed for Off. Then the next morning, everything worked fine as if nothing had happened the night before. I took the hint and replaced the 12V battery and no gremlins since, though it has only been a week...knock on wood!!!!

 

You might also consider contacting "Re-InVolt" over in North Carolina.

Bob Wilson

 

It is both a safety issue and you can easily screw things up. Maybe you should start by visiting techinfo.toyota.com and downloading the relevant repair pages, to see whether this job is within your comfort zone.

If the traction battery is bad I don't think you'll cause further damage by driving the car; but you can't expect to drive very far or very fast, and you easily could be stuck on the side of the road when the battery finally gives out.

 

Dealers sometimes use a pass/fail battery tester that isn't accurate enough for a Prius. But it's easy to test the 12V battery yourself without tools. See the procedure here:
http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html
If you're lucky the traction battery is fine and only the 12V is bad. If not, attend to Patrick.

 

Based on what I've read here on PriusChat, and my auto tech training, your 12v battery is marginal. I replaced the 12v in my 2005 with similar voltages. I was not having trouble, but my wife drives our car out of town a lot. I did not want her to be broken down somewhere. Plus, I price shopped my local dealers and saved $50.00 on the battery (may have just been lucky) and installed it myself. So, it cost me $120.00 instead of the $200 plus (including installation) that my wife would have had to pay on the road.

My buddy commutes with his 2005 and sometimes gets low voltage too. He wants to gamble on getting more life from his 12v, so he's still running his. And he doesn't fix anything himself, so he'll pay labor either way.

My point is, count on replacing your 12v battery in the near future (probably less than one year).

And keep us posted on the costs and procedures associated with the re-involt battey. They sound very interesting.

Thanks, Dan

 

Sciencekit, the 12v battery voltages are not good. IMO no excuse for the dealer telling you it is "ok". For the record here is the Maintenance Mode procedure:

You can easily check out your battery status/charging system using the MFD in maintenance mode. No tools required.

1. Get your Prius into "Accessory Mode" - Press the power button without touching the brake pedal.
2. Put the MFD into "Maintenance Mode" - Press and hold the "Info" button on the MFD while turning the headlights on and off 4 times.
3. Press the "Menu" field on the screen.
4. Press the "Display Check" field.
5. Press the "Signal Check" field.
6. The 12v battery voltage will be one of the items listed, it should be above 12 volts. If it is lower, either the battery needs replacement or the charging system is not functioning correctly - see step 7.
7. Put a small load on the battery by pressing the power button again without touching the brake pedal. The voltage should stay above 12v. If it drops significantly, you need a new battery.
8. Now get your Prius into "Ready Mode" - step on the brake and press the power button. The battery voltage should immediately rise to 13.8 volts (Your Prius uses constant voltage charging). If it is lower, the battery will never charge; if it is much above 14 volts, your 12v battery will get cooked.
9. Shutting the car down will reset the system back to normal operation.

If you need to get a new 12v battery, you can opt for a dealer replacement or get a better battery at a lower price at: http://www.elearnaid.com/12vo1topraub.html
and install it yourself.

JeffD

 

The 12v battery is a standard Japanese size so the only place you'll find an exact replacement is the dealer. If the car won't boot up just jump start it then drive straight to the dealer.

 

If you are going to keep the car, replace the 12v first, no further angst. THEN, if the traction battery is still throwing DTC codes, replace it.

It is just too easy to be fooled by a faulty 12v into thinking something else is wrong.

 

Still have the battery if you want to drive and get it...