Autoweek's attempt to take down the Prius

Is Autoweek still in business?

 

I never had problems with the Mercedi I had.....but had to call Toyota Assistance yesterday: the 12V battery was almost empty....the doors unlocked and that was about it...
Drove ~30 mi on saturday , none on sunday, and monday it didn't start. It wasn't really cold (around freezing) and nothing was left on.

After the car was jumpstarted I drove to the dealer and left it there: it was scheduled for service ("free" service at pick up it still had to get and new map software and USB connection) today but as I was already there, they gave me a Auris hybrid (not available in the States I think) and are working on it at the moment.

The guy that jumpstarted the car (independent, local non-Toyota assistance hired by Toyota) said it happens frequently (empty 12V battery in Prii) and they don't know what causes it.

Not a flawless start with Toyota for me!

But no worries: I still like the car and he/she is gonna stay!

 

Did you intend to reply to another thread?

If your 12 volt is dead, driving it 30 miles won't be enough to charge it up. Patrick Wong (a repair expert here) has suggested for a Gen 2 to leave it in READY mode for 8 hours (2005 Prius beeps when door is open, then won't start | PriusChat). Driving it won't make it charge any faster/slower. And, if it's be killed once, it may not hold a charge well again.

If your car isn't driven much or is driven short drives, you may want to get a slow (below 4 amp, IIRC) battery charger. I asked for suggestions at battery tender/maintainer suggestions | PriusChat and ended up buying an Optimate 4, made by TecMate International - OptiMate Battery Chargers.

 

No , I wasn't replying to another thread, just mentioned that my Germans weren't that bad....and my Toyota left me stranded in a week....

I'm new to Prius and I don't know how the aux battery is charged....there's no alternator/rectifier-combo in the car (not an old fashioned one).
Is the aux battery charged from the main battery?

My workplace is 10 mi from home. I guess I bought the wrong car as it is used for commuting 90% of the time?

 

FWIW, Mercedes reliability of vehicles sold in the US can be really hit or miss and in the recent past were mostly not good.

When you say 10 mi from home, do you mean 10 miles or 10 minutes? If 10 miles, how many minutes is the drive? It's not the distance that matters but the time the car is in READY mode. If it's only getting 20 minutes of READY mode/day, that might not be enough to keep the 12 volt charged.

The 12 volt is charged via the DC to DC converter inside the inverter unit and only when in READY mode. Are you running the car a lot in ACC or IG-ON mode (like to listen to the stereo)? That drains the 12 volt.

If you have a nav system, can you run the test at Weird stuff happening? MPGs dropping? Test The Battery | PriusChat after the car has sat overnight? Tell us the 3 values (don't go changing the battery w/o telling us). If you have no nav system, you'll need to measure the 12 volt battery voltage yourself w/a voltmeter. Would be interesting to know the voltages at each step. If low, you might want to charge up the 12 volt.

 

Just turned in the Auris hybrid and got my Prius back.
They changed motor oil (5W30) and brake fluid and checked everything (standard 30K km/2 year service)
They also updated the map software to 2012/2013 and installed a USB connector in the armrest (not standard in EU, only aux).

Going to work is 10 miles and that takes me some 20 minutes, 75% highway.

On saturday my wife took the manual and sat in the car for a couple of hours getting used to the car.
While she was doing that, the car was in "ready" : every now and then the ICE started to keep the temp as set.
It was getting darker and the (auto) LED lights were switched on.

After that I drove the car for 45-60 minutes: dark, lights on.

Does the lighting and fan and radio/nav drain the 12V battery while in "ready"?

The dealer checked the aux battery and (of course) didn't find anything out of the ordinary and they charged it overnight.

I had a V-Checker in the car for a couple of days, so I can check the voltage.

I didn't use it yet to check the voltage, but only to check the rpm's, coolant temp and speed.
The Prius speedometer turned out to be very optimistic...the OBD info is correct (checked with GPS) but the display is around +10% off.

 

The good news is the Prius can be driven and enjoyed and it does not cost a kings ransom to own like some other cars. You know the ones that fall apart when the warranty expires and cost 3 to 4 times traditional parts to replace.

 

I had one Merc that I bought when it was 10 years old and I drove it for 9 more years.
When I sold it, it had 400K miles on it and never let me down.
I guess I was lucky!
And it was an old school diesel....no fancy electronics.
Once the rectifier diode blew (yes, that happened but didn't leave me stranded) while I was driving to work.
Slowly all lights died, even brake lights and turn signals.
But the engine kept running. I left it at the parking at work for 8 hours idling and after work I drove it to the dealer.
They replaced the diode ( 19 euros including labour) jumpstarted the car and I drove it around to recharge it.
Draining a lead acid battery all the way is never good...but I had no choice.

BTW: MB parts here are way cheaper than Japanese car parts.

 

Those trips should be long enough. Sitting in READY mode will not drain the 12 volt and yes, if the ICE was turning itself on periodically to keep the HV battery charged and provide cabin heat, you were in READY. You can turn on the lights, radio, use nav, etc. w/o issue as long as you're in READY and not IG-ON. Again, driving or sitting parked while in READY makes no difference in terms of 12 volt battery charging rate.

I haven't looked at your video yet, but maybe that V-Checker was causing a drain when the car was off? You do want to look at the voltage BEFORE going into ready mode after the car has sat overnight.

 

In this mode I often draw up to 1 kW for days during power outages. No problem.

The OBD has an unswitched, constant 12V so any load after the car is turned off will drain the battery. This is one reason why the Scangauge and Graham miniscanners have a very low power, sleep mode.

Bob Wilson

 

I don't wait for it to made into toilet paper.