# 12 volt battery on a Prius



## ameliasaws (May 1, 2020)

Does anyone know how the 12 volt battery on a 2011 Toyota Prius is charged? I can't tell by looking at it
Amelia


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## Nealtw (Jun 22, 2017)

ameliasaws said:


> Does anyone know how the 12 volt battery on a 2011 Toyota Prius is charged? I can't tell by looking at it
> Amelia


What is the problem? Does it have a fuse in line?


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## ameliasaws (May 1, 2020)

The battery went flat, I took it out and charged it. I am just wondering how it gets charged from the car. I can understand the charging method of the main batteries.


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## Nealtw (Jun 22, 2017)

ameliasaws said:


> The battery went flat, I took it out and charged it. I am just wondering how it gets charged from the car. I can understand the charging method of the main batteries.


I don't know the details for that car but how old is the battery? Is it working after you charged it?


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## lenaitch (Feb 10, 2014)

@Nik333 - don't you have a Prius? I recall a thread not long ago about Prius' and their batteries.


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## Nik333 (Mar 1, 2015)

lenaitch said:


> @Nik333 - don't you have a Prius? I recall a thread not long ago about Prius' and their batteries.


That doesn't mean I understand it completely!!! I know you can go to Auto Zone and they will check your small battery, I think in the parking lot. The big battery is very expensive and like many items on the Prius, I'm finding , the average person should save up to replace items. Mine's a 2010 gift Prius. It doesn't seem to like extremely hot or cold weather. On the Instrument Cluster in front, you should have a visual for how the car is charged. The top right box. It has energy transfer lines when the car is in motion.











I'm uncomfortable doing much work on the Prius because it's mostly computers. I don't want to mess it up. I did put oil in today which is remarkably uncomplicated.

This Toyota dealership is kind enough to write a blog -






Charging a Toyota Prius Battery | Details and Information | Houston, TX


Do you have a Toyota Prius? Are you unsure on how to charge your auxiliary 12v battery? Read more or come visit our Toyota dealership in Houston to learn more about this today!




www.joemyerstoyota.com





For anything more complicated I would go to a Toyota dealership. My cousin bought me the car. He's an Aeronautical Engineer and he says to go to the dealership. His grandaughters have Priuses.

I had a terrible experience in Sacramento, last May, when a rare tow-truck company (many are short on staff due to COVID) promised to find a good mechanic for me when my car broke down in the wildfire smoke and extreme heat. He towed me to a man who had taken a course and wanted $200 upfront. It turned out it was low on gas. (But, I didn't find that out until I was towed home to a Toyota dealership I know who charged me $12.50.) It seems to run out of gas quickly in high heat & smoke. Maybe it's the just the A/C was working hard. I thought I had plenty of gas.

I live over 100 miles from Sacramento and didn't know the dealerships. It turned out there were at least two in town that I could have been towed to.

This is California, but, it's pretty bad when you find yourself in a bad neighborhood with a disabled car and the armed guard at the Marijuana dispensary on the corner tells you the mechanic you've been towed to is a tweaker. 🤣 There must be competition. All police were at a shooting.

Find a good dealership near you!


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## lenaitch (Feb 10, 2014)

Nik333 said:


> That doesn't mean I understand it completely!!! I know you can go to Auto Zone and they will check your small battery, I think in the parking lot. The big battery is very expensive and like many items on the Prius, I'm finding , the average person should save up to replace items. Mine's a 2010 gift Prius. It doesn't seem to like extremely hot or cold weather.
> 
> I'm uncomfortable doing much work on the Prius because it's mostly computers. I don't want to mess it up. I did put oil in today which is remarkable uncomplicated.
> 
> ...


I was just thinking you might remember the thread. I'm not sure if it was about Prius' or EVs in general. Or I'm hallucinating.


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## Nik333 (Mar 1, 2015)

lenaitch said:


> I was just thinking you might remember the thread. I'm not sure if it was about Prius' or EVs in general. Or I'm hallucinating.


It was my thread & I got yelled at. 😊

It's about the hybrid battery more than the 12V.


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## Brainbucket (Mar 30, 2015)

If I remember correctly, the 12-volt battery is the auxiliary battery. It is charged by the generator that is the main transmission/starter/generator that charges the main and auxiliary batteries. If the auxiliary battery is bad, car won't start.


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## ukrkoz (Dec 31, 2010)

12V in Toyota hybrids is charged off the traction/hybrid battery, *when vehicle is moving,* via 12V inverter.
If a hybrid sits for long time, it self drains. You either need to drive vehicle ever so often for about 30 min or, place a battery tender onto the 12V.
There are relatively inexpensive OEM Panasonic analogs. Energizer, for example, or Duracell make AGM deep cycle batteries that work fine with hybrids and are just over $100. No need to fork $500 by now for OEM Panasonic.


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## papereater (Sep 16, 2016)

lenaitch said:


> @Nik333 - don't you have a Prius? I recall a thread not long ago about Prius' and their batteries.


Yup, I think that was me. Ended up I simply bought a new battery as it was 100% dead. AZ had it, no Walmart, or other like Costco.


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## papereater (Sep 16, 2016)

Nik333 said:


> It was my thread & I got yelled at. 😊
> 
> It's about the hybrid battery more than the 12V.


OK, now we have 2 members claiming that thread was about them....LOL. How about we share that claim and privilege?? But no one yelled at me.


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## Jim Port (Sep 21, 2007)

ukrkoz said:


> 12V in Toyota hybrids is charged off the traction/hybrid battery, *when vehicle is moving,* via 12V inverter.
> If a hybrid sits for long time, it self drains. You either need to drive vehicle ever so often for about 30 min or, place a battery tender onto the 12V.
> There are relatively inexpensive OEM Panasonic analogs. Energizer, for example, or Duracell make AGM deep cycle batteries that work fine with hybrids and are just over $100. No need to fork $500 by now for OEM Panasonic.


I wish it was that cheap. I just replaced the MILs 12v for $200.


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## Nik333 (Mar 1, 2015)

papereater said:


> OK, now we have 2 members claiming that thread was about them....LOL. How about we share that claim and privilege?? But no one yelled at me.


There was more than one thread. Mine was older and slightly different subject. I'm not telling what the title is. ;D


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## ukrkoz (Dec 31, 2010)

Jim Port said:


> I wish it was that cheap. I just replaced the MILs 12v for $200.











12v ALTERNATIVE


Credit goes to a CD poster howardc64 Looks like group 24 batteries are a perfect fit. Got one from Pep Boys (Bosch AGM 24) that measured 10" x 6.5" x 8" so identical to the Panasonic. The +- posts are in the exact same location as the Panasonic (group 24F (I guess F=flipped?) has the +-...




www.toyotanation.com





Those are slightly bigger but gives idea what to look for


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