There are a laundry list of items on cars that you simply have to accept as sacrificial and will need to be replaced on a regular basis: oil, fuel, tires, filters, and, of course, batteries. Most of those you have no real control over the life cycle of, assuming you actually drive your car, except batteries. They’re the one expensive expendable on your car that you can take control of the life cycle.
On average, you can expect a standard flooded-cell battery to last about five years if you drive the car regularly. That’s the other atypical thing about batteries, they actually benefit more from regular driving than sitting since they receive a charge via the alternator (or generator on pre mid-’60s cars) as you drive. As a matter of fact, the longer your driving stints are, the better for the battery; short trips never allow the battery to get a good charge and sulfation occurs. It’s all those single-digit-mile trips or sitting around when your car is parked that does in a lot of batteries. If your car sits a great deal or only comes out in the spring and summer, your battery might only get you through a year or two. Why is that?
Well, in a standard wet-cell battery a few things begin to occur. As it discharges, the lead cell plates take on sulfates from the acid solution they are submersed in (hence the term “wet cell”). That buildup decreases the battery’s potential to generate current through chemical reaction. If this is allowed to continue, the voltage and current potential will continue to drop until the battery is unable to crank the car. Proper charging or recharging will help return the sulfate back to the solution since it effectively pushes off the sulfate from the lead cells and returns it to the solution, but it needs to be done on a regular basis. Lack of use can also result in stratification, meaning the roughly 35 percent sulfuric acid and 65 percent water solution can separate with the acid sinking to the bottom. Charging will usually restore proper distribution among the cells.
Dry cell, or absorbed glass mat (AGM) batteries, such the ones from Optima, have a much higher resistance to solution while sitting inactive since the acid solution is suspended in the mats rather than in fluid form. Potential for both sulfation and stratification are decreased since the acid is more controlled. That also makes them leak free, no matter the mounting orientation and are not as susceptible to hydrogen gas release during charging. Yes, batteries do that, so ventilation during charging is always important.
With that in mind, the single best thing you can do to greatly extend or restore the life of any battery is to keep it regularly charged. That’s a simple proposition in any weather with a maintenance charger like Optima’s cool new Digital 400 12V Performance Maintainer and Battery Charger. We were impressed with its features and ease of use. Once you hook it up, you never really have to think about it again!