Technology has changed a lot since our cars first started rolling off assembly lines. The amount of electronics today is staggering, and the batteries in our cars are required to do more than simply get the engine going. Power demands have become more specialized and our car’s electronics have adjusted to meet the demand, but there are still a few facts that remain.
Battery construction has changed a lot in recent years, but since the jump from six volts to one dozen, the power requirements have remained relatively constant. But what is the BEST voltage for your “12-volt” battery? As we all know, the voltage will fluctuate depending on use.
Optima Batteries gets that question often, and they’re working hard to get the right information out there to help prolong the life of any battery. They have even devoted a section of their YouTube channel specifically for the technical side of battery care. There are a few things you should know before we get into the “perfect” scenario for your battery’s voltage. First, while your battery is called a 12 volt battery, if it has only 12 volts, it is significantly discharged. Every 12 volt battery is comprised of six cells that produce roughly 2.2 volts per cell. Do the math, and that means your “12 volt” battery should have 13.2 volts, much more than the advertised 12.
Since batteries store energy and their voltage will fluctuate, is that the BEST voltage to keep it? Unless you’re driving your car regularly, every battery will lose a charge over time. Also, even small drains such as your radio’s memory feature or various other systems will wear down a battery over time.
How Far Is Too Far?
Optima’s parent company, Johnson Controls, manufactures both Flooded Lead-Acid batteries and the spiral-wound Absorbant-Glass-Mat (AGM) Optima brand batteries. While the design of each differs, they still have the same voltage recommendations for long life. Optima recommends that a battery’s voltage should not drop below 12.4 volts, as that is the voltage when sulfation begins to occur internally within the battery.
Sulfation builds up over time and eventually, will diminish a battery’s performance and life span. The best way to prevent that is to keep a battery’s voltage above 12.4 volts. Many chargers, such as Optima’s Digital 400 and Digital 1200 chargers use micro-processors that constantly regulate the voltage of your battery and keep it in a state of readiness, even with the common draw of station presets and various other normal voltage drains of today’s cars.
If you don’t have a self-regulating charger, you can also use an analog style charger but would need to regulate the battery’s state yourself. Don’t leave a standard, non-regulated charger on any battery for an extended amount of time, as it could eventually overheat the battery and ruin it.
Instead, keep an eye on your battery’s voltage and when you see it drop to 12.5 volts, simply hook up the charger and bring it back to full charge. You could also disconnect the battery if you are not planning on using the car for some time, perhaps over the winter. This will help limit the draw on the battery.
Also, starting the car and running it for a short time may help scratch that itch of hearing your exhaust and that amazing, performance camshaft, but it doesn’t help the battery as much as you might think. Starting the car takes a significant amount of a battery’s capacity, and without running consistently at higher rpm, the alternator may not produce enough energy to replace even what was used to start the car. Thereby leaving your battery in a worse-off state than if you didn’t start the car at all.
We’re huge proponents of driving our cars, and with a properly-working charging system, will keep your battery charged up. But if that’s not an option, then keeping your battery in mind will help ensure that it’ll be ready whenever you are.