I was out early this morning, to do my daily meet and greet of the various rodent families that take up home in my Prius (actually, I was checking fluid levels, etc.) when I decided to get really crazy and play around with the voltmeter (I just learned how to use it in a very limited fashion this winter). Well, Prius 12V battery, which is four months old, checks fine. Then I thought I would get really wild and check the battery on the '03 Camry. The car is a Japan-built 5-speed manual and still has the original 12V Panasonic battery. It's maint. free, but I noticed the little sight glass built into the battery was showing red. Checked that a few weeks ago and it was the "all is good blue color." The sticker on the battery said red means it needs water. So, I scraped off some stickers, which allowed me to get to the plug things and I unscrewed them and added distilled water. Did not really need that much, but they did need some. Sealed it back up and checked the battery. It read 12.81 V The car has not been run for a couple of days. Anyway, got to thinking -- the battery is 11. Has been no trouble whatsoever. Other than to check voltage as I did, is there any other check I should/could make?
About all you could do is take the car to an auto parts shop that does free battery load testing. Would give you a chance to see how much cranking capacity that reliable old battery has left. Actually, noting if the starter turns the engine as fast as you ever remember will do about the same thing.
my dodge dakota battery is approaching it's 10th birthday and 24,000 miles. if it ain't baroque, don't fix it.
While I absolutely agree with the "if it ain't broke, don't 'fix' it" theory, that doesn't really apply to batteries. Think about your daily activities with that car. If it would be a major inconvenience to have the battery go dead on you sometime soon, then get a new one. The new AGMs have a long life and really ARE maintenance free (the sealing caps should NOT be removed...ever. )
If the terminals are dirty or corroded, clean them with a little baking soda and water. You can get a wire brush made for the purpose. Then sand the terminals and clamps with some fine sand paper to expose fresh, clean metal. If the car sits for an extended time, charging up the battery once and awhile is a good idea. If the OEM battery isn't AGM, don't use an AGM for a replacement. Once a battery is charged the car's electrical system and smart chargers will send a float, or maintenance, charge to the battery. This is to counteract any self discharging. Flooded and AGM batteries have different voltage requirements for this. Using the wrong voltage can shorten the battery's life.
-NASA, just before Challenger exploded during launch, 1986. (Well, they didn't actually say that, but that is how they behaved with a known issue.) -NASA, just before Columbia broke apart during re-entry, 2003 (Well, they didn't actually say that, but that is how they behaved with a known issue.)
Unless the charging system is set for excessivly high voltage 14,8-15+V, I would not be concerned about using an AGM replacement battery. The spiral cell AGM starting battery made by Optima (red top), or the Exide Orbital starting battery which is a lower priced clone of the Optima, have been exceptionally long lived in my autos and farm equipment. I have well over a dozen of those spiral cell AGM starting batteries in use, many are 15+ years old and still starting the machines like new. The charging system were originally intended for conventional flooded cell batteries. My little shop built, 305 Chevy powered yard tractor, that is used near every day, still starts fine with the Optima red top battery I installed when I built the tractor 21 years ago. Their expensive, but most will wear out the new machine their installed in.
The car in question here is not THAT old so it should not be a problem. If the charging voltage is less than 14 volts, it should be fine. If it is14.5 or more, it might not be fine. In general, however, I believe what you said is not true for vehicles less than 15 years old or so. The AGM design is so vastly superior that it is still a good buy. Even if the charging system reduces it's total life a bit, it still should be longer than an old style lead acid type.......especially for people who don't know or care about checking the electrolyte level occasionally.
1) The only time the battery has seemed to struggle with starting was during our February snow/ice storm when the temperature was about 5 degrees F. Otherwise, no issue. 2) My husband, who actually does do some car work (though not really on the Prius, another story), has this odd quirk. He triplecoats all car batteries with no-corrode spray -- when he bought the Camry new, he pulled out the battery sprayed ALL the hardware, battery, clamps, tray, etc. His batteries never have crud build-up. I think we'll just go on relying on the Panasonic at the moment. One of us can walk if it dies and no readily available jump is nearby. When (if?), it dies, I would almost go for an Optima. My father has put them in his cars and has had great luck -- EXCEPT -- I think I may shun them now based on recent posts on this forum. Still thinking about that.
The battery in my 2013 Sonic is 'maintenance free' sealed but is still a classic flooded battery. Same for the one in the wife's 2001 Sable. AGM batteries are superior, but they do cost more. Which is why for most car models the manufacturers stick with floodies to keep costs low. Because of the cost difference, I just recommend sticking with a flooded battery.
A "classic flooded battery" can NOT be totally sealed because of the gasses produced during charging and discharging. And I think if you look at all but the very cheapest new car models, you will find that the vast majority of them do have AGM batteries already. If your new battery costs twice as much but lasts MORE than twice as long.......the only way I'd recommend the classic one is if you won't be able to eat for the rest of the week if you spend the extra money.
lead acid, flooded batt's are fine. in and older car you may be better off. They are less expensive and usually last me 5 years or more. so a car with 200k and 10 years old would likely be better off cost wise with the cheaper batt. if you car turned over slow with cold weather last winter. I would reccomend changing before next winter.
Re: older car -- Had not really thought that through, but you are right, probably makes more sense to buy a $75 Exide.... Re: Slow start at 5-degrees -- it is very seldom we get below 30 degrees F. here, so while next winter might be the end, not too worried yet. Indeed, just noted you are in Roseburg. I am in the Coast Range at about 1,000 feet, so our weather is not much different.
No lead acid battery can be totally sealed. All the sealed ones, AGM included, have a valve to relieve any excess pressure. The issue with using the wrong float charge is that it can cause the battery to overheat, vent, and eventually dry out. I really wish starter battery type was listed along with the other specs of a car. It would be nice to know if a charger needs to be set to AGM without having to take that plastic cover off the battery. If we take the OP case for an example, an AGM will last 22 years potentially. That's great, but is that really worth the extra cost when it will exceed a car's average useful life?
Well I hadn't really considered the age of the car.......but you are right on there, unless the owner intends to go for 15 years or another 100K miles. A pressure relief valve is quite different than an atmospheric vent. And finally, the float voltage has to be WAY off and applied for a LONG time to do any real damage. Any "smart" charger should be just fine for occasional relatively short term use. Some of them shut off completely when not needed; most others float around 13.2 and that should be fine for an AGM, which actually needs a float voltage a few tenths higher to keep a peak charge. Keeping it at 98 instead of 100 percent should be no problem at all.