Low voltage battery

suomi · 01-06-2006, 04:09 PM

Hello everyone.

This is my first post to priuschat,and I bring you greetings from Finland (it is located in north Europe).

I got my -04 Prius about 6 weeks ago. It was the local Toyota dealers showcase car, which had 5500 miles (9000km) on the meter, so basically a new car. I have enjoyed my miles with the Prius and I am happy with the mileage although it is cold here during the wintertime and my driving distances are short.

However, I have had one unhappy experince, which occurred on the morning after a relatively cold night, 5 F (-15degC) in mid December. First of all, the SmartKey function and central lock were out, so I had to use the key to get in. When I try to Start, the lights came on, but the hybrid system did not activate, instead some relays kept clicking, the display unit went dead and the system sort of got stuck before the Ready state.

I was slightly panicing, since at first I was unable to get it to switch off. The lightes kept dimming and finally after many attempts on the Start button it finally switched off. After calming down, I realised that the 12V battery was dead so I charged the battery for 8 hours and the system came back alive again.

Initially I was sure that the 12V battery was bad, so I went to Toyota shop to claim for a new battery. They tested the battery and the tester showed it was still OK. To my disappointment, Toyota shop did not replace the battery, they claimed that Toyota warranty does not cover unless the tester indicates that the battery is dead.

The next week was rather nervous driving, I avoided using most of the 12V devices to avoid problems. However, despite the cold, the system has been working wery well ever since. Then I started to think what could have been the reason for the loss of battery charge. I was 100% sure that there were not lights left on, so it had to be something else.

I am now rather convinced that the problem was the use of front seat heaters. I have used all the other devices after the event, since I know they are part of the Prius standard factory package. The front seat heaters are standard for all Prius models sold in Finland, but I believe they are not factory installed. The Prius 12V supply comes through a DC/DC converter from the high voltage battery, and it has a rating of 1.12kW. It is not much, and if the seat heaters are on, it just maybe that the charger capacity is exceeded. It may also be that there is a safety function which actually switches off the supply from the HV battery in order to safeguard it, and this would lead the quick discharing of the LV battery.

I thought I'd share this story to learn if anybody else has had similar events, or related issues with the 12V battery, and perhaps even solutions.

Thank you in advance.

GreenMachine · 01-06-2006, 04:42 PM

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.

Brian K · 01-06-2006, 07:19 PM

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.

andyprius · 01-06-2006, 08:34 PM

Quote:

Originally posted by suomi@Jan 6 2006, 04:09 PM
Hello everyone.

This is my first post to priuschat,and I bring you greetings from Finland (it is located in north Europe).

I got my -04 Prius about 6 weeks ago. It was the local Toyota dealers showcase car, which had 5500 miles (9000km) on the meter, so basically a new car. I have enjoyed my miles with the Prius and I am happy with the mileage although it is cold here during the wintertime and my driving distances are short.

However, I have had one unhappy experince, which occurred on the morning after a relatively cold night, 5 F (-15degC) in mid December. First of all, the SmartKey function and central lock were out, so I had to use the key to get in. When I try to Start, the lights came on, but the hybrid system did not activate, instead some relays kept clicking, the display unit went dead and the system sort of got stuck before the Ready state.

I was slightly panicing, since at first I was unable to get it to switch off. The lightes kept dimming and finally after many attempts on the Start button it finally switched off. After calming down, I realised that the 12V battery was dead so I charged the battery for 8 hours and the system came back alive again.

Initially I was sure that the 12V battery was bad, so I went to Toyota shop to claim for a new battery. They tested the battery and the tester showed it was still OK. To my disappointment, Toyota shop did not replace the battery, they claimed that Toyota warranty does not cover unless the tester indicates that the battery is dead.

The next week was rather nervous driving, I avoided using most of the 12V devices to avoid problems. However, despite the cold, the system has been working wery well ever since. Then I started to think what could have been the reason for the loss of battery charge. I was 100% sure that there were not lights left on, so it had to be something else.

I am now rather convinced that the problem was the use of front seat heaters. I have used all the other devices after the event, since I know they are part of the Prius standard factory package. The front seat heaters are standard for all Prius models sold in Finland, but I believe they are not factory installed. The Prius 12V supply comes through a DC/DC converter from the high voltage battery, and it has a rating of 1.12kW. It is not much, and if the seat heaters are on, it just maybe that the charger capacity is exceeded. It may also be that there is a safety function which actually switches off the supply from the HV battery in order to safeguard it, and this would lead the quick discharing of the LV battery.

I thought I'd share this story to learn if anybody else has had similar events, or related issues with the 12V battery, and perhaps even solutions.

Thank you in advance.

[snapback]184972[/snapback]

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

john1701a · 01-06-2006, 09:22 PM

Quote:

Originally posted by suomi@Jan 6 2006, 04:09 PM
It was the local Toyota dealers showcase car
[snapback]184972[/snapback]

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.

deh2k · 01-06-2006, 09:40 PM

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.

hdrygas · 01-06-2006, 10:38 PM

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.

suomi · 01-08-2006, 09:07 AM

Hei,

Thank you all for your replies.

It is comforting to hear that there are people using Prius in cold climates without problems. The condition of the battery is for sure one of the concerns, and it is rather difficult check if it is really OK or not. I will follow up the situation and I will let you know if there are any new discoveries around my Prius battery.

suomi

Astrotoy7 · 01-08-2006, 09:19 AM

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 !!!

deh2k · 01-09-2006, 07:54 PM

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

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01-06-2006, 04:09 PM	#1
suomi Join Date: Jan 2006 Posts: 3 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Hello everyone. This is my first post to priuschat,and I bring you greetings from Finland (it is located in north Europe). I got my -04 Prius about 6 weeks ago. It was the local Toyota dealers showcase car, which had 5500 miles (9000km) on the meter, so basically a new car. I have enjoyed my miles with the Prius and I am happy with the mileage although it is cold here during the wintertime and my driving distances are short. However, I have had one unhappy experince, which occurred on the morning after a relatively cold night, 5 F (-15degC) in mid December. First of all, the SmartKey function and central lock were out, so I had to use the key to get in. When I try to Start, the lights came on, but the hybrid system did not activate, instead some relays kept clicking, the display unit went dead and the system sort of got stuck before the Ready state. I was slightly panicing, since at first I was unable to get it to switch off. The lightes kept dimming and finally after many attempts on the Start button it finally switched off. After calming down, I realised that the 12V battery was dead so I charged the battery for 8 hours and the system came back alive again. Initially I was sure that the 12V battery was bad, so I went to Toyota shop to claim for a new battery. They tested the battery and the tester showed it was still OK. To my disappointment, Toyota shop did not replace the battery, they claimed that Toyota warranty does not cover unless the tester indicates that the battery is dead. The next week was rather nervous driving, I avoided using most of the 12V devices to avoid problems. However, despite the cold, the system has been working wery well ever since. Then I started to think what could have been the reason for the loss of battery charge. I was 100% sure that there were not lights left on, so it had to be something else. I am now rather convinced that the problem was the use of front seat heaters. I have used all the other devices after the event, since I know they are part of the Prius standard factory package. The front seat heaters are standard for all Prius models sold in Finland, but I believe they are not factory installed. The Prius 12V supply comes through a DC/DC converter from the high voltage battery, and it has a rating of 1.12kW. It is not much, and if the seat heaters are on, it just maybe that the charger capacity is exceeded. It may also be that there is a safety function which actually switches off the supply from the HV battery in order to safeguard it, and this would lead the quick discharing of the LV battery. I thought I'd share this story to learn if anybody else has had similar events, or related issues with the 12V battery, and perhaps even solutions. Thank you in advance.

01-06-2006, 04:42 PM	#2
GreenMachine Senior Prius Poster Join Date: Oct 2005 Location: Vermont Posts: 732 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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.

01-06-2006, 07:19 PM	#3
Brian K Join Date: Apr 2005 Posts: 152 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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.

01-06-2006, 09:40 PM	#6
deh2k Senior Member Join Date: Jul 2004 Location: New Hampshire Posts: 239 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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.

01-06-2006, 10:38 PM	#7
hdrygas Senior Member Join Date: May 2004 Location: Olympia Wa Posts: 3,650 My Car: 2004 Prius Package: #9 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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.

01-08-2006, 09:07 AM	#8
suomi Join Date: Jan 2006 Posts: 3 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Hei, Thank you all for your replies. It is comforting to hear that there are people using Prius in cold climates without problems. The condition of the battery is for sure one of the concerns, and it is rather difficult check if it is really OK or not. I will follow up the situation and I will let you know if there are any new discoveries around my Prius battery. suomi

01-08-2006, 09:19 AM	#9
Astrotoy7 Join Date: Dec 2005 Location: Melbourne, Australia Posts: 108 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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 !!!

01-09-2006, 07:54 PM	#10
deh2k Senior Member Join Date: Jul 2004 Location: New Hampshire Posts: 239 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	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