Posted: May 01, 2020
Battery Maintenance in the Time of Coronvavirus
Summary for the TLDR crowd: You need to charge your car battery with a battery charger!
Lockdown, stay at home, safer at home...whatever the directive might be called, the end result is that vehicles all over the world are being driven a whole lot less than they were before the Coronavirus pandemic began. So what happens when millions of cars and trucks sit unused for weeks or even months at a time? The batteries discharge, often to the point that they won't start an engine.
Why do car and truck batteries discharge if those vehicles aren't being driven? Because modern cars and trucks are packed with all kinds of electrical accessories and features, from memory seats, radio presets, integrated car alarms, satellite-based tracking systems and even Internet connections. All of those accessories and more depend on electricity to operate and when a vehicle isn't being driven, that electricity comes from the battery.
Older vehicles that don't offer all those modern conveniences can and often do sit for months at a time without being started and their batteries have no trouble turning an engine over, but newer cars and trucks? Many will discharge their batteries to the point that they won't start within a matter of weeks. Auto manufacturers know all of these modern features demand more electricity and they've responded by building vehicles with increasingly larger batteries.
Case in point, the 75/25 OPTIMA REDTOP battery is listed as a direct-fit replacement for the 2000 Chevy 3/4-ton pickup with the 6.5-liter diesel engine. Fast forward to the 2020 Chevy 3/4-ton pickups with the 6.6-liter diesel and the direct-fit replacement battery is an H6 YELLOWTOP. Big deal, a newer truck takes a different battery, right?
It is a big deal, literally. The H6 battery is physically larger and weighs in at 54 pounds, while the 75/25 weighs just 33 pounds. That's an increase of 63%! It's not about the cold cranking amps needed for starting a high compression engine, because both diesel engines have similar displacement and the H6 is rated at 800CCA, while the 75/25 isn't far behind (~10% less) at 720CCA. The big difference is the reserve capacity. The 75/25 is a 44Ah battery, while the H6 is a 72Ah battery, an increase that mirrors the weight difference of more than 63%.
Having 63% more reserve capacity is critical for newer vehicles, because their key-off electrical load can be far higher and more-demanding than what was common just a generation ago. To put some math behind it, we'll say an older vehicle with a 44Ah battery has a key-off load of 25 milliamps. That vehicle will deplete that reserve capacity by .6 amps per day (.025 x 24 hours). That means that battery will become completely discharged in about 73 days (44Ah/.6 amps). That assumes the battery is fully-charged when the vehicle was parked (many are not) and does not take into account extreme temperatures, which can accelerate the discharge process.
By comparison, a newer vehicle may have a key-off load of 75 milliamps, but a larger 72Ah battery to help compensate for that increase demand. In a similar scenario, that battery will be completely discharged in just 40 days (72Ah/1.8 amps). Keep in mind, a battery will typically need to have some amount of charge in it, if it is going to be able to deliver enough energy to start an engine, so the point at which a battery can no longer start an engine could arrive a week or two before the 40th day of sitting. Many modern vehicles also have key off loads that can be significantly higher than 75 milliamps, which means they will discharge a battery even faster.
The end result is that many new vehicles on the road today can discharge batteries to the point where they won't start an engine in a matter of weeks. Auto manufacturers know this and if you search eBay, you'll probably find listings for used solar panel chargers that some auto manufacturers installed in vehicles when they left the factory in Europe. Those panels helped make sure the batteries survive sitting in parking lots and cargo ship holds for several weeks or months between leaving the factory and arriving at dealerships. But this is a minor issue that can be solved by a set of jumper cables, right? WRONG!
Jumper cables are great for emergency situations, but they are by no means an adequate substitution for correctly and fully-charging a battery with a quality battery charger. If you ran out of gas and were stuck on the side of the road, a spare one-gallon can could be a life-saver, but wouldn't your next stop be a gas station? If you don't have that same mindset to seek out a battery charger after jump-starting your vehicle, you are placing a tremendous strain on an alternator that was designed to maintain batteries near a full state of charge, not recharge deeply-discharged batteries.
Relying on jumper cables and an alternator to recover a deeply-discharged can lead to a cycle of dead batteries and jump-starts until either the battery fails or the alternator fails, neither of which is necessary. So what can you do to maximize battery performance and lifespan? Keep your battery fully-charged with a quality battery charger or maintainer. You'll notice we try to make a point of encouraging the use of "quality" battery chargers and maintainers, because you do get what you pay for in that regard.
OPTIMA obviously makes quality chargers and maintainers that we highly recommend but there are other viable options as well. The best chargers are microprocessor-controlled and have specific settings for AGM batteries. Chargers and maintainers to avoid are those that do not offer such features and those typically found in the bargain bins near the checkout. Deficient chargers may not properly regulate voltage and amperage and could damage batteries, so don't take a chance on what seems like a cheaper option.
So how often should you charge your car or truck battery? Fully-charged, most batteries will measure at least 12.6 volts (OPTIMA YELLOWTOPs will measure at least 13.0 volts). When a battery is discharged below 12.4 volts and is left sitting in that state, sulfation starts forming in the plates, which diminishes capacity and lifespan. If you've been staying at home a lot and don't plan on driving your vehicle on a regular basis, hook it up to a quality charger or maintainer and keep that battery ready to go. If you do drive your vehicle on a regular basis, considering hooking it up to a charger once a month or so, just to make sure it is staying topped off.