[ukrkoz]

2010 Camry Hybrid Trunk Battery Life? I own a 2010 Camry Hybrid (59,000 miles) that still has the original trunk starter battery. I have had no problem starting the car ever. I know you can have the battery tested, but wanted to know from other forum owners how long I can expect from the battery and when it would be prudent replace it to prevent getting stranded. Planning on keeping the car for the duration.

Answer to this question is very simple.

They last very long time. There is no high load on those batteries caused by starters. My 12V was made in 2006, OEM Panasonic, and is still working as backup battery for gate opener.
We had several owners that reported OEM batteries fail, but it does not appear to be a significant number.

 

[chris_s]

12V Battery

I have a 2010 as well. It has about 124,000 miles. It's very durable and only needs normal maintenance. For a TCH 'normal' can be a lot less than for non-hybrids. I just replaced the rear brake pads and that's the only brake maintenance that it's had so far other than lubricating the slides.

I looked into the 12V battery a few months ago because 6 years is the point at which these batteries might start to fail. I looked at the replacement (Optima) batteries and they are pretty expensive. I thought about possibly getting a replacement just to be sure that I didn't get a surprise one day. Before getting any deeper into it, I decided to get a new voltmeter to see if the battery was down at all. I measured it and it was still around the 12.6 volts you should get on a healthy battery. At that point, I stopped worrying about it. I'll check the voltage now and then just to be sure that it's OK. As per the previous post, these batteries aren't under much strain and usually last quite a long time (probably well beyond 6 years). A meter is pretty cheap for some peace of mind (or you can have your garage check it).

 

[chris_s]

12v Battery Lifespan

Just to put a little bit of science behind this topic, this file pertains to one specific brand of deep discharge batteries but it also has a lot of general information.

Link

Probably the most useful bit of information is the chart on page 10 which shows the lifespan (cycles) versus the capacity of the battery used for each discharge. Given that this battery is only used to start up the electronics, there is a good chance that it doesn't even use 10% of the battery capacity to get the car started. As you can see from the chart, for an AGM battery (which I believe that this is) you can get 3100 discharges if each is 10% of the capacity. If the car is used once per day, that would be about 8.5 years. The caveats are:

• These lifespan numbers are for a similar (but different) battery.
• It will depend on the amount of discharge for each start cycle (which I don't know). It might be < 10%.
• How many times the car is started each day (on average) is a determining factor in the number of years the battery will last.
• Extreme temperatures (especially heat) will shorten battery life.
• Letting the car sit without being run for long periods and allowing the battery to gradually discharge reduces battery life.
• Overcharging the battery reduces battery life.

Thus, if Toyota have over-provisioned this battery such that each discharge uses less than 10% of capacity, it is quite possible that it will last 10+ years. In a Prius forum, I saw that users reported their batteries lasting 5 - 8 years. The TCH battery is apparently bigger than the stock Prius battery but maybe the drain is similar.