Low voltage battery

Could it be possible that your rear hatch wasn't completly closed? There have been several posts on here where batteries drained down by the light which would then be on.

 

Using the seat heaters might be causing it if they draw alot of current. Try not using them and see what happens.

In years past I had 4 100w lights mounted on a small car (30a alternator). On more than one occaision I entered the car in the AM just to find the battery dead. After awhile I traced the problem to me parking the car with a dead battery. The lights (and whatever else was on) drew more juice than the alternator could supply. My solution was using them only when I absolutely needed them, not whenever I had the chance, not all 4 at once, and I made sure to run the car with the lights off for a few miles before parking it. Maybe that will give you some ideas.

Someone else posted recently with a similar problem, that time it turned out to be a faulty battery. Next time it goes dead, don't charge it before taking it to the dealer, let them have the full problem.

 

Hello Suomi, Interesting letter, your English is very good. Not ever having experienced the weather in Finland, I imagine it is quite severe though. My personal opinion of the Prius 12VDC Battery is that it is inadequate, when compared to other "Normal" car batteries. However, that said, it basically provides computer voltage to power the car up. So... any accessories left on or in a high current draw condition can affect the Prius Battery. Adding your severe Winter conditions and the problem is multiplied. One has to baby the 12V battery. My advice is to carry a charged spare. I use a 12VDC Sealed Gel, 7 AH and keep it plugged into the accessory plug in constantly so it"s SOC is always good. This can then be used as a "jumper battery" to initiate powering up. Andy

 

There were quite a few reports of the Classic model that were showcase cars being delivered to customers with the 12-volt auxilary battery having been abused.

They test ok, since they can still hold a full charge. But the catch is that it can't hold the charge for long after that... due to the dealer showing off the car so often without actually driving it. And short test-drives are hardly representative of actual driving either. That starting of the system so many times, looking at the instruments, then shutting the system off is one of the worse things you could do to any 12-volt. But they did that anyway.

I suspect the same happened with yours.

Living in Minnesota, I see temperatures just as cold as in Finland... only the artic blasts don't last as long. -18F is my record. This is my third winter with the HSD. And never have I had even so much as a hint of any battery degredation.

 

My Prius has gone through a winter when I left it outside overnight several times when the temperature went down to around -30C. I have never had any trouble starting it in the morning.

The 12v battery should have plenty of power to start the car unless something has drained it, regardless of the temperature.

 

You let your baby get cold!! Shame on you. Actually if you did not buy the car new you do not know how the battery has been treated for those miles. As far as I know it can get cold in Finland from time to time. I would look into replacing the battery.

 

yeah, id take it to whoever is responsible for serviicng it and ask them to have a looksee at the battery.

its often been 40-44 degrees celsius here for a few weeks now, I am unlikely to be experiencing this problem due to the seat heaters !!!

 

I read in another Prius group that some others experienced 12v battery drain. This TSB for the JBL amplifier was mentioned. I don't know if it applies to this particular situation, but it seems like something to consider.


File : /TSBs/2004+ TSBs/AU001-05.zip
Description : August 2, 2005. Parasitic draw from JBL amplifier. 2004-2005

Prius and other Toyotas. Some owners may hear a POP noise when turning the
ignition on or off, because the amplifier remains on even though the car is
off (which may result in a dead 12v battery after an extended cold soak.
Replace with updated JBL amplifier.

You can access this file at the URL:
http://groups.yahoo.com/group/toyota-prius...Bs/AU001-05.zip

 

Interesting that my dealer advises disconnecting the 12v battery if the car is to sit for 7 days or longer. It's claimed that the Hybred batteries suck the life out of the battery. I find this difficult to believe, but m wondering what the ramifications are if I do disconnect the battery (or if it does drain down in 7 days).......

 

It is not at all true that the hybrid battery sucks the life out of the 12v. It is true that Prius has a smaller 12v battery than almost all other cars. There is a small drain (on the order of 30 milliamps in the new model), which will eventually discharge the 12v battery to a level where the starting procedure will fail. In addition, a small light left on or the JBL audio power drain problem (both mentioned already in this thread) will accelerate the discharge.

Once a battery has been drained to a nonfunctioning level (especially in temperatures below freezing) it will not recover its originaly capacity, even after being recharged.

Disconnecting it for a non-driving period will eliminate all of the "parasitic loads", but the radio presets and clock will need to be reset afterwards.

 

Another point is that once the READY light appears, the car isn't using the 12V battery, but is providing 12V from the DC to DC converter (and charging the 12V battery). I don't think you need to keep the radio and fan turned off to save the battery once the car is running.

 

"Once a battery has been drained to a nonfunctioning level (especially in temperatures below freezing) it will not recover its originaly capacity, even after being recharged."

Couldn't resist adding my note of affirmation here.
Have had similar problems with our little Gen 1 from our local fleet. Like you say esp. in cold weather. I doubt this will help the Gen 1 owners much on warranty but here is All Data's info on the Aux BATT. capacity situation. There is also info in there advising suppliers not to leave Priuses 'dead on the docks' for too long also.

2001-2003 Toyota Prius L4-1.5L (1NZ-FXE) (Hybrid)
Vehicle Level Starting and Charging Battery Technical Service Bulletins All Technical Service Bulletins Auxiliary Battery - Hard Staring/Low/Dead Battery


Auxiliary Battery - Hard Staring/Low/Dead Battery
Notes

ELECTRICAL
EL014-03

October 2, 2003

Title:
BATTERY CAPACITY IMPROVEMENT

Models:
'01 - '03 Prius

Introduction

Some customers may complain of not being able to start their vehicles after extended parking times and/or repeated short driving times. The purpose of this TSB is to inform you of a new battery and mounting hardware available to improve the storage capacity performance of the Prius.

Applicable Vehicles^ 2001 - 2003 model year Prius vehicles.

Parts Information
28800-21190 Replacement Battery 04003-23147 Kit (includes oversize tray, new + terminal)

Warranty Information

Applicable Warranty*:

This repair is covered under the Toyota Comprehensive Warranty. This warranty is in effect for 36 months or 36,000 miles, whichever occurs first, from the vehicle's in-service date.

* Warranty application is limited to correction of a problem based upon a customer's specific complaint.

Repair Procedure

1. Remove battery ground wire from vehicle. (The new battery ground wire is included with the battery installation kit.)

2. Remove positive terminal/block assembly from wire harness.

3. Place terminal/block assembly in a vice as shown and remove nut attaching terminal end to the block.

4. Attach new positive terminal to the terminal/block assembly.

5. Remove battery hold down, auxiliary battery, and battery tray from vehicle.

6. Install new battery tray and battery.

7. Reattach wire harness to positive block and attach positive terminal/block to new battery.

8. Install new ground wire.

9. Route vent hose from battery to rubber grommet in trunk floor.

10. Double check that the battery and battery wires are secure and install battery cover.


Sorry the pic's didn't paste but you get the general idea. Our 2005 had no trouble this winter despite the cold and in fairness to the 2002 it IS now about 4 years old with 48,000 mi.
Like you all say they boot right back up after battery replacement except for the radio presets.
BTW using an external 'keep alive' was not recommended during changeover.
I still can't help wondering if something doesn't come on periodically during the coldest temps because my old Batt was not THAT bad on the bench. Probably would have made it another summer.
Hey anyway there IS at least one thing that a Prius owner can DYI besides the oil.

 

...or that the seat heaters haven't (yet) killed the new battery.

 

Is the spare battery charged by a charger which is plugged into the plugin or do you have it hooked up directly to the accessory plugin? I would appreciate details/pictures on the setup between the battery and the accessory plugin. TIA.