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Discussion Starter #1
If the gasoline engine gets turned over by the hybrid battery pack, do we even have to worry about the 12V battery powering the electronics and accessories until there's a warning on the instrument cluster? With our regular ICEV, I'm thinking of replacing them every four years or five years, just before the onset of winter. Not sure if hybrid owners shouldn't even worry about the 12V battery.

I understand there is no starter or alternator on Toyota's hybrid vehicles.

Edit:
Didn't know if the battery is flat, we got to jump start it too:
 

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The answer is a definite YES!
Its a tiny little thing with very little poop. Think motorcycle battery. If it ever gets fully discharged the life expectancy is decreased considerably. Here in the desert you can expect a lead battery to last 4 years, and they die abruptly. Being "sheltered" in the passenger compartment, these batteries will have a little more life since they avoid temperature extremes.

On average the hybrid system OE 12v batteries last 4-6 years.
The thing to remember with this one is that if its dead you can't open the rear hatch to get to it. There's a host of other issues that a dead 12v can cause, meaning you want to avoid it. I recommend replacing them on spec at 4 years, but if you have never run it down it could last another year or two. A good quality replacement battery should last a lot longer. They're not cheap though, you need to get the right type with the vent pipe.
 

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Discussion Starter #3
Sounds like we have to buy from a Toyota dealership? Is it safe to buy lead acid battery on ebay with couriers throwing boxes around? Batteries can get damaged with excessive vibration during transport, right?

I'll likely buy from the States if my local dealership charges much more.
 

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You can buy them anywhere for about 1/2 what the dealer charges, but it has to be the right type. eBay wouldn't be my first place to look.
 

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The big question is, does the RAV4 hybrid alert about problems with the lead acid battery? It's pretty easy to monitor it, since resting voltage drops as the battery degrades. Given how many electronics there are, it would have been trivial to monitor battery voltage, even how fast it discharges while parked. Is that monitoring there? I don't know.

I'm surprised there aren't Li-Ion drop in replacements for lead acid batteries by now.

3 cell units would be perfect.

3*4.2v=12.6v 100% charge, just like a lead-acid

So if it's a 46aH, 21 2200mah cell per bank, 63 cells total, and would weigh about 6 pounds total.

20aH 12v Li-Ion packs sell for $40-50, so 46aH would be roughly $100. And it would last at least 3 times as long as lead-acid, if not the life of the vehicle. :D
 

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Way too expensive, especially when you consider cooling requirements, electronics and related safety requirements.
There are no cooling requirements. Electronics (which includes safety and charging circuitry) is a few dollars extra. Every single device using Li-Ion has them. Cell phones, laptop batteries, hoverboards, power tools, cameras, etc.
 

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One of my previous cars was a Mazda Miata, which comes with a AGM battery like our Hybrids do. The life expectancy of the battery was usually 7 to 9 years on average, compared to the normal lead-acid battery life of 3 to 5 years. You can be proactive in changing out a battery early, but the chances of the battery totally failing without warning is rare. I am going to carry a jump starter to use as a back up to use if my battery fails. The jump starter is a Lithium Ion battery and You only need to energize the starting circuit to activate the hybrid battery that runs and powers the Rav. The small battery only runs the 12 volt accessories and that is why it is so small. Getting a larger battery does not guarantee more cranking power as our battery does not crank our engine. A better quality battery means more than the size of the battery. Determining the quality of any battery is hard to find out about in a subjective manner.
 

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In fact after some Googling it looks like they are already available.

14aH @ $144

https://www.cyclegear.com/parts/shorai-lithium-battery-lfx14l2-bs12?gclid=EAIaIQobChMIidyvt--21gIV1LrACh0FTAz2EAkYASABEgKvX_D_BwE

Once the mass production of Li-Ion 18650 cells for Teslas and other electrics starts, they should significantly come down in price.

I'll stick with proven AGM tech considering all the lithium battery fires that have happened in recent years, the Duracell lead acid battery has a 4yr free replacement warranty, the Optima has a 3yr warranty, the 2yr warranty(likely prorated) on the cyclegear battery doesn't speak well of the mfr's confidence in the product..... nor mine.
 

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I'll stick with proven AGM tech considering all the lithium battery fires that have happened in recent years
Li-Ion batteries are no more dangerous than the Ni-Cads that power the RAV4 hybrid, or the Li-Ions in newer Toyota hybrid systems.

The Chinese knock-off hoverboard fires were the result of cost cutting. Proper protection circuits and proper charging methods were ignored to achieve rock bottom prices. Given how many devices are out there with Li-Ion batteries, and how many fires actually happened, they are some of the safest electrical devices.
 

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Li-Ion batteries are no more dangerous than the Ni-Cads that power the RAV4 hybrid, or the Li-Ions in newer Toyota hybrid systems.
Sell that idea to the hundreds of people who have experienced exploding phones and tablets. Put a lithium battery in the rear of the Rav and then get rear-ended and enjoy the fire that comes next. The traction batteries are encased in steel and have active cooling plus complicated thermal controls.
 

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Discussion Starter #18
One of my previous cars was a Mazda Miata, which comes with a AGM battery like our Hybrids do. The life expectancy of the battery was usually 7 to 9 years on average, compared to the normal lead-acid battery life of 3 to 5 years. You can be proactive in changing out a battery early, but the chances of the battery totally failing without warning is rare. I am going to carry a jump starter to use as a back up to use if my battery fails. The jump starter is a Lithium Ion battery and You only need to energize the starting circuit to activate the hybrid battery that runs and powers the Rav. The small battery only runs the 12 volt accessories and that is why it is so small. Getting a larger battery does not guarantee more cranking power as our battery does not crank our engine. A better quality battery means more than the size of the battery. Determining the quality of any battery is hard to find out about in a subjective manner.
We've got too of those Li-on jump starters too that I haven't had the chance to use.

Eventually, someone with a hybrid here will experience a flat 12V battery and we'll see how it goes. Hopefully it happens in the morning or at the parking lot so it isn't too much of an inconvenience for us.

=====

Will the 12V battery ever die while the car is in motion? What would happen in this case? Do we have more time to drive and park the car safely? With regular ICEV, there will be telltale signs like the charging indicator to let us know if the alternator isn't charging the battery, correct? Not sure if it's any different on our RAV4H's.
 

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^^^
When the 12v batt fails the hybrid system will constantly try to charge it, which results in the ICE running more and lowered MPG. Apart from that, you'll know because the system won't boot up, or more likely there's an assortment of system glitches while it is booting up. Often they are still capable of booting it, but just barely, so things get wonky.

Again the biggest problem is that you can't open the rear hatch to gain access to the battery, so you need a jump under the hood or you crawl back and open it manually.
 

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Yes - it will need to be replaced, as other people have mentioned, in perhaps 5 years +/-. I haven't had the pleasure yet in my RAV4 Hybrid, but my previous car was a 2006 Prius for which I was lucky and didn't have to replace the 12v battery until the 7 year point. At the time, all the auto shops and specialty battery shops quoted about $300-$400 for the job, parts and labor. After that sticker shock, I decided to do it myself. Paid $170 for the battery, online. It took me about an hour after watching a YouTube video. It was a little tricky to access the battery in the trunk, as there was some interference to remove and required some long extensions for the socket wrench.
 
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