Weird stuff happening? MPGs dropping? Test The Battery

p.s. it's £90 just to buy the battery from the dealer as well... we don't have any auto parts stores here. there are online ones, but i just don't trust them. the last thing i need is something faulty going in a ruining my car anymore.

 

hey everyone i have a 2006 prius i think package 7 backup camera bluetooth and navigation ..... i have searched and really havent found an answer yet ...

i was driving the past few days in the north east PA/NY/NJ and noticed two times the red triangle light came on and says "problem" (i think ) i have searched and found no real answer to why ... i did find a post in here and tested my battery which i will do again tomorrow also but it showed 14v when charging ... it seemed to happen when i applied pressure to the brakes .. could it be a brake issue? im not sure

 

Thanks!! Got a new Battery and my possessed vehicle has dissappeard. And I am now the cool sister who knows about the secret computer screens on the prius.

 

It's not the charging voltage you need to be so concerned about. You need to check the voltage when the car is off, with no load and after it has sat overnight.

 

Hello Everyone,

I was looking for a bit of help as I am unsure if I have a dealer trying to get one over on me or if I really do need to replace my battery.

I went to the dealer because the headlights (usually just the left) on my 08 randomly go out and I must turn them off and on again to turn them back on (this while driving on the road). I took my car in to have my lights replaced via the class action settlement/ warranty extension and the guy there said he did a "level 5 diagnostic" and that my battery is low (" there were multiple low voltage warnings in the history") and that should be replaced first as it may be the cause of the headlight issue. He then proceeds to charge me for this diagnostic that I never asked for or authorized , hence, the lack of trust.

When I checked via the navigation screen I see:

no load:12.1
load:11.9 (drops to 11.8 when I apply the brake)
on:14.2 (at first 14.5 then an immediate drop to 14.2 and when the engine kicked on 14.1)

If it matters it is a 08, nav, smart key

I have never had a warning light except for when I attempted to drive with my drivers side door open (oops ;-) )

Should I replace this battery?
Could it go in a few days to couple weeks max as the service adviser said?
Would it make my headlights randomly shut off until I twisted the on off knob?

Thank you in advance

While I am asking my GFs 08 (yes,...they match...we are dorks...) has

no load:12.3
load:12
on14.2
Is she about to die on the road or is she fine?

Thank you so much!

 

1. Battery is not the cause of your headlight problems. Toyota HID lights stink.
2. You need a new battery...not critical yet, but get one soon as possible. Many users here recommend the Optima yellow-top...I've got one.
3. GFs battery is weak, but not as bad as yours. If she still has original battery, it's just about time to replace it.

 

Thank you MJFrog,

you rock.:rockon:

Just to be clear:

I should replace the battery ASAP meaning this week or ASAP meaning this year? Same for my GF.

Thank you again for your help!

 

Thank you Mr. Shumacher,

I was just unsure as I have experience no symptoms at all and would not have know about this if toyota did not do the test.

Thank you!

 

Sometimes the only symptom people notice is reduced mpg and the engine running more often then it should. This is usually right about the time the battery is calling it quits.

 

So, our 2005 battery shows 11.8 volts with no load after sitting overnight in cold weather, and then 11.3 with a load. However, we haven't any warning lights or other indications that the battery is bad. Our fuel economy seems a little low, but we've only had the car for a few months (only in winter), and we make mostly short trips. Is it best to replace the battery as a preventative measure, or do you think I should wait longer? Thanks!

 

I would replace it but I am sure some will say it may still be ok for a while longer.

 

...or at least carry a spare 12V source. It doesn't take much -- I'll bet you could start the Prius with 8 AA cells, but any of the "emergency startup battery" gizmos would do the job. They're $20 and up. Or, just have your AAA card handy and wait for a jump.

 

Okay, maybe I'll bite the bullet. If it increases our fuel economy so much the better. Thanks the for replies.

 

And I'll bet that when we do get some credible data on it we'll be disappointed. I may be missing something, but the extra energy expended to maintain the failing battery doesn't seem like enough to materially affect MPG. IMHO, the only reason to replace the 12V battery is if it is too weak to maintain enough charge to start the car after a normal period of inactivity. If I had suspicions about it, and was going to leave the car in an airport parking lot for 2 weeks in Frostbite, Alaska, then a precautionary replacement might be in order.

 

You are not including the fact that the engine may run more often then it should. That is where the actual loss is supposed to come from. Because a failing battery usually drops someone into the mpg realm of a non-hybrid car of similar design the theory kind of makes sense. You basically have a Prius without engine stop technology.

 

I don't buy this at all, sorry. My buddy's 06 had a failing 12v battery and a new battery increased mileage slightly, but had no noticeable effect on the start/stop frequency of the ICE.

 

That is the basic theory. That is why we asked for more data. We need more than weak anecdotal evidence that sounds more like a scene out of Ferris Bueller's Day Off.... "My bestfriend's sister's boyfriend's brother's girlfriend heard from this guy who knows this kid who's going with the girl that saw your buddy's car fail to turn off at a stoplight because his 12v battery was dying.

 

All battery failures are not the same. A battery can quietly die, just refusing to take a charge. Or a battery can short and turn itself into an electric heater. It's this latter mode that eats power which reduces mileage.

Tom