Battery lifespan tends to be tightly bound to temperature. The warmer the environment, the shorter the lifespan (for the types of temps expected to be encountered for the application).

A battery in a temperature controlled environment such as an equipment room held between 60 to 70 degrees F, can be expected to last up to 10 years or more. I've seen this with my backup generator start batteries, essentially very big 12 volt units.

 

Does the Optima battery generate sulphuric acid and need to be vented, or is equal to the Toyota OEM battery? It it needs venting any plans on how you would do it?

 

I would agree that 36 months seems early for a quality battery to go bad. Also, I thought absorbed glass matt (AGM) batteries were supposed to last LONGER than the normal car battery -- thus partially the justification for the higher price. But on the other hand, my lousy OEM Bridgestone tires wore out around 25k miles with conservative driving, diligent rotation and maintenance.

Now I'm worried. I assume I could just have a mechanic test the battery when I get the oil changed next. Would that help? Do they die a gradual death or is it usually a sudden failure?

 

AGM batteries typically do last longer than regular lead-acid batteries. The usual failure mode of a lead-acid battery happens when a plate warps enough to touch an adjacent plate, creating a short. The plates of an AGM battery are separated by fiberglass mat, which prevents them from shorting. Because shorting is prevented, the typical failure mode of an AGM battery is chemical, and failure is gradual instead of sudden.

AGM batteries typically retain the hydrogen and oxygen inside the case, and recombine it to water, so they don't lose water. However, they also have overpressure valves to release the gas, when there is too much gas to hold. The gas venting occurs during periods of heavy gas-generation, which occurs during rapid or over charging. Gas production is increased by high ambient temperature.

If you keep the batteries in temperature-controlled space, and never rapid-charge or over-charge, AGM batteries can last many years. In some communications systems "float" applications, for example, AGM batteries are scheduled to be replaced at 20 years, though premature failures do occur. But, if you over-heat and over-charge the battery, it can still "boil" the water, and failure can occur in a very short time.

So, the life expectancy of an AGM battery depends on the usage, not the calendar. In automotive usage, in a particular model of vehicle, I expect the battery life depends on how smart the engineers were in designing the charging system. For TCH, we probably don't have enough history to know that, yet.

 

Ken,
Optima batteries, like all lead acids, have sulfuric acid in them. They only "vent" if excessive internal pressure builds up which can happen if they are charged at too high a rate (not likely in your Camry or my Prius due to the "constant voltage" charging regime). My Prius battery IS vented as it is in the hatch area with no separation from me (breathing battery fumes is not good). Yours is in the trunk area so unless you have fold down rear seats, there is little risk of breathing the fumes.

The Optima's do have provisions for a vent tube. You can buy the low cost adapter kit from http://www.elearnaid.com/pakitforinop.html and run a tube out to the rear wheel well if you want to play it safe.

JeffD

 

Captain Jim and McGyver - since you actually did this did you bother to vent your Optima installations, or do you think it is nothing to worry about?

 

I agree with the others. Heat plays a big role in battery life. I'm in Southern California and in my experience, after 3 years you are taking a gamble, especially with lesser quality, OEM style, commodity batteries. The rare one that makes it 4-5 years has the owner bragging. I just prefer not to take the chance of a dead battery on such a complex automobile that is now entirely my responsibility to maintain.

Plus, I'm a big geek... I kept the old AGM battery and will use it as part of my solar panel project in the back. As long as it is still good, it won't go to waste.

 

McGyver, good move putting the old GSM battery to use. What do you use your solar panel project for?

I read - probably in another forum - that someone was proposing using the old, not quite dead, hybrid battery packs in battery farms that would store unused electricity for the utilities. Sounds like the old packs will be put to use like your GSM battery.

 

Captain Jim here. In reply to the question "did I vent the Optima 12 volt AGM battery." the answer is no. An AGM does not need to be vented as such. Certainly not with the low charge / discharge that is required for the 12 volt battery. Heck, it does not even get used to spin the starter. The High Voltage battery does that! It simply runs the computer to start the whole thing up. And then powers the 12 volt systems, headlights, radio, electronics, etc. The AC is powered from the High Voltage battery also, not the 12 volt system. I have no reservation on the Optima 12 volt battery installation. Jc

PS: Yes the Optima is carried at Costco, but they only had two sizes, Costco had a small size yellow top, which I bought but could not get to properly fit (too small for the hold down clamp). And they had a blue top marine battery with side and top terminals which also would not fit, (too large for the hold down clamp). I ended up at a auto parts store in town. Jc

 

So the Optima is a AGM battery - thanks Captain Jim. I didn't see this stated in the thread before so the no venting required makes sence.

Isn't the Optima brand carried at Costco? I'll have to price it the next time I'm there.