12 Volt Battery Replacement / Upgrade on a 2007 Toyota Camry Hybrid with photos

Three years old and 30,000 miles, is a reasonable time to replace a 12 volt battery.
Mine died in my driveway, thus giving me more options than 100 miles away from home.
In the end the battery measured 1.7 volts, not the typical 12 volts, the battery gave me signs that it was dying, the key would not start the car twice about 10 days before the battery quit. It was a omen of bills to come, I just didn't know it.
Having the time to research the OEM Panasonic S65D26R battery, I found that the S65D26R is an AGM type battey, and costs $320.00 from Toyota. Paying Toyota this amount of money would NOT be my first choice. The battery warranty is somewhat like the tire warranty, independant of, and outside of, the overall Toyota warranty. What so much? Well the OEM Toyota battery is an AGM, Absorbed Glass Mat battery. An AGM differs from the typical lead acid battery as it has an absorptive material between the positive and negative plate of each cell separating it and allowing the liquid electrolyte to contact both material, you may think of it a providing a 99 to 100% humidity inside of each the six, 2.1 volt cells that make up the 12.6 volt battery. Since they are sealed, they will not vent to the atmosphere and loose their moisture, unless there is a dramatic pressure differential (this happens very rarely) , and then a small pressure relief valve will monetarily open. Since this is in your trunk space, an AGM is the best overall choice.
Battery websites, like Interstate battery say that I could replace my battery with a typical lead acid battery for about $75 bucks. This is a real option, you just need to know that you may have battery fumes in your trunk from it.
But there is a two wire connector that also comes out of the OEM Toyota battery. This is a temperature sensor, it measures 2.27 kilo ohms FYI. It is meant to monitor the temperature at the battery to prevent over charging. You remove it from the OEM battery by pealing back the top sticker, and by using a small screwdriver on the hot glue, pry and pop the sensor free.

I chose to put in an Optima yellow top Starting Deep Cycle, size D35 with bottom spacer battery, it cost $225.00
these are the batteries that are used in Alaska, and they last 7+ years.

You will need a 10 mm 1/4" drive socket and extension.

There is enough space and wire to have the positive and negative terminals in front, or in the rear, as you mount the battery.

I attached the sensor to the battery with a tie wrap to the hold down bar, and mounted the connector with double sided tape.

There will be a spark as you make the final connection, this is normal.

Since you removed the 12 volt battery, the "Check Hybrid system" message will appear on the console. I just power cycle the car three times and it will reset the computer and remove the message.


It is Ok to send a message to me via email. Jc

 

3 years and 30k miles seems to be early for a battery to fail. Anyone else have this happen to them?

 

Good writeup. You might want to consider running a piece of plastic or rubber hose from the battery vent to the outside. The vent fumes could contain small amounts of sulfuric acid which could over time corrode the inside of the trunk.

Edit: Thinking further - an external vent would be required for safety reasons. Lead-acid batteries vent hydrogen and it might be possible for enough to build up in an enclosed area - like a trunk - to form an explosive mixture. When I get a chance I'll look up what the lower explosive limit for hydrogen is.

Edit Again: Just read up on Optima batteries. They are AGM and should not vent anything. Please ignore my stupid advice above. It's what I get for spouting off without researching first. Duhhhhh....

 

Hydrogen build up should not a problem, the gas is of such a small molecule that all it needs is a pin hole to escape confinement, a battery doesn't make all that much, its the sulphuric acid fumes you want to vent.

 

Wet cell, (or AGM) batteries are a commodity item for OEM's. 3 years is an outer marker for reliability. This is my bread and butter in the trucking and public transit industry. If Optima ever takes over a large portion of market share, I'll probably lose my job.

Optima makes a fantastic product and the OP is very wise for going this route, especially the Yellow Top, was an educated choice.

Now I'm motivated to make this upgrade, BEFORE it fails on my 07.

Great Post!

 

Well, I'm done. I decided to go with the Optima Red Top, group 24. Really an even bigger battery would have fit with little modification. I chose the Red Top because I can easily drive a high current inverter off the side terminals (flat GM style). It's less expensive too.

I used an old 12volt scooter battery and some alligator clips to keep the computers on life support during the swap, so no fault code occurred.

Anyone with an '07 should know the clock is ticking on these batteries. This is an easy and inexpensive fix/upgrade.

Thanks for the motivation Ken!

 

I wonder if this is covered in any part by my 7 year 100k mile extended warranty?

So far so good - even though the car sat outside for 4 months last winter without being run at all...

BTW - It started as though I had shut it off the day before...

 

I am not sure I understand the need for venting. If the OEM battery is not vented to the outside, and the replacement battery is the same technology, then why would the Yellow or Red tops need to be vented outside?

Someone please clarify, I have an 07 which hasn't seen the inside of a dealership since I purchased it, I guess I would replace the battery myself also.

BTW, 56k miles, and the OEM battery is still aok so far.

 

If the replacement battery is indeed the same technology then there would be no need to vent. The TCH battery and perhaps the Optimas as well (will have to check) are designed to generate very little hydrogen gas during normal operation - and to contain and reabsorb what little they create. Hence no need for a vent. Traditional design batteries OTOH generate and vent hydrogen as a part of (IIRC) the charge cycle. This hydrogen can build up in an enclosed area until an explosive mixture is formed. Also the escaping hydrogen can carry with it corrosive vapors of sulfuric acid. There is usually a label on these types of batteries warning of this issue.

 

I personally consider any 12V not lasting at least 5 yrs to be quite disappointing. 3 1/2 years on my Camry so far, and I have 6 1/2 years on my Sienna's OEM battery. My previous car , a Cavalier got 8 yrs out of the battery before replacement. My old Firebird was 8 yrs old when I sold it with the original battery, and none of the other cars I had from new ever required a new battery, but they were all in the 3 to 6 yrs old range at the time...