In an attempt to save some weight on my 2012 Camry Hybrid, I am considering taking out the Panasonic battery in the trunk and putting in a Braille (15 pound) or NRG Cell (14.5) pound battery. Has anyone done this?
There are a few things to consider.
The OEM battery is rated at about 50 amp hours and is non vented because it is located in a trunk. The 2012 has no vent connections if you try to replace it with a battery that has a vent connection. The Toyota battery apparently costs about $400 to replace, so you may want to consider that before throwing it away.
The TCH has no need for any 12 volt cranking amp rating. The 245 Volt battery cranks the engine. The 12 volt really only provides control power and buffer capacity. The biggest load on it is when the headlights are on delayed off. But, in more practical terms the Smart Key system in the car is powered on all the time and presents a low but constant drain. This means you need a larger capacity battery or it may go flat if you leave it parked for a long period of time - months not days. At the end of the day the capacity of the battery will determine how long you can park it. If you go down to a 10 amp-hour battery, you many only be good for a couple of weeks or so. See the other thread at the forum with the "TCH Storage" title, for more information.
What I would like to see Toyota do is go to a vented deep cycle battery and squeeze it in under the hood somewhere. It would be cheaper and make more room in the trunk. Under the hood you do not have to worry about venting. This car should not need a $400 12 volt battery. With the proper design a $50-75 one would be just fine.
This all said, an AGM type battery is a good replacement for the original. It could be much cheaper than getting one from Toyota. But, I would go for one that has at least 30 amp hours.