Replacing a battery on a car is no longer a simple matter. Just like replacing coolant and motor oil is now also a complex matter.
Lead acid batteries come in three types.
The standard acid poor battery that we are all familiar with. These come in varying degrees of quality. There are a lot of junk Far Eastern batteries of this type around.
Then there are the non pour lead acid batteries. These are of two types.
The Gel battery.
The absorbent glass mat battery (AGM).
I have three tractors, four vehicles, a stand by generator and a boat. All having different requirements for batteries.
Now lets take the AGM battery first. Good quality AGM batteries should last 4 to 8 years or so.
The vehicle must have a temperature compensated charging system, and also be able to sense the low internal resistance of these batteries. Since the internal resistance is lower they require a lower charging voltage. Also the internal resistance drops with temperature and so the charging voltage must decrease with ambient temperature. The big advantage of these batteries is that they can provide very high instantaneous current on a repetitive basis. They are less prone to sulfonation in a low battery state and have a low rate of internal discharge.
If they are over charged their hydrogen is released and the battery becomes instantly useless. If the battery is inside the car, these batteries must have a vent for hydrogen to the outside.
They are expensive. If you charge these batteries you must use a charger with an AGM setting or you will ruin the battery.
On vehicles that stop the engine when the vehicle is stationary, and many do now, AGM battereis must be used.
So my Toyota Camry Hybrid uses an AGM starting battery. It has a temperature probe, and a hydrogen vent as it is in the trunk. It can only be supplied by Toyota and cost $350. I have just replaced it at 9 years.
If your vehicle has electric power steering, and most do now, then I strongly advise using an AGM battery for your safety and those you share the road with. I recommend that even if the vehicle was not supplied with one, as long as the charging system is temp compensated. I think pretty much all vehicles with high frequency digital voltage regulation are.
Four years ago I got a classic customer letter from GM about the steering on my Chevy Equinox. The letter stated that the power steering could suddenly fail for a period of time and cause the vehicle to potentially wander into oncoming traffic. The letter gave no explanation for the problem and told me not to contact the dealer unless I had the problem. I contacted the dealer who told me customers had experienced the problem, but they had been unable to rectify the issue even after replacing the whole steering system.
So I researched this, and found an excellent paper from BMW on the matter. The problem is latency in digital voltage regulators coupled with standard lead acid batteries being unable to provide the peak currents required during the charging ramp up latency, particularly with aging batteries. They had recorded voltages as low as 7 volts at the steering control unit, making it inoperative. In Europe VW/Audi and BMW did a recall to install AGM batteries.
I immediately installed an AGM battery in my Chevy Equinox. I would STRONGLY advise any of you that have vehicles with electric power steering to replace your battery with an AGM as long as your charging system is temperature compensated. Interestingly GM could not tell me whether my charging system was temperature compensated or not. So I had to devise a test to see if it was or not. It was.
Now the Gel batteries like the Optima series.
I really like these batteries. Although expensive you come out money ahead by miles every time.
They are light, can be placed in any position, and are very long lasting. They do have a higher rate of internal discharge and so need a battery maintainer for intermittent use.
They can be used for any application were an acid poor battery is used, as long as one the right size is available. They will release their hydrogen if overcharged, but do not need a special battery charger.
I have had two of these in my diesel Suburban for 15 years at least now and still going strong. I keep them on a maintainer in the winter.
I have had one in my Willys jeep since 2002 and still going strong.
I have had one on the house generator that has a maintainer on it for 16 years now and still going strong.
I use a marine Gel battery on the boat. The last one lasted 14 years and that is a severe environment. Before these batteries you were lucky to get four years of use under marine conditions. The Gel batteries take the severe pounding of marine use. Their long life easily justifies their higher cost. I reckon they last at least three to four time as long as standard lead acid batteries.
The JD Model A uses two 6 volt batteries in series, and the JD 420 uses one six volt battery.
There are a lot of junk batteries out there now.
For some time now I have only used lead acid and AGM batteries from
Penn State, under their DEKA brand. These are long lasting batteries with good cold weather performance and made in America. The 1958 JD 420 is a two cylinder high compression engine, and only DEKA batteries give good reliable starting performance. They are all made in the USA. There is no foreign junk from that quarter.