The average battery life in 12-volt automotive applications is approximately three to five years, as are marine batteries. Motorcycle and powersport batteries are typically a little shorter, at two to three years for a conventional SLA battery. It makes sense to test a battery as it nears its expected lifespan, monitoring it for diminishing condition. But is that enough?

There’s an excellent argument for more frequent testing than that. In fact, if you’re a service facility for any vehicle with a 12-volt system, the recommended standard is to test every battery in every vehicle that comes through your shop, every time.

What does that look like? Equipping your service drive with a testers like the MDX-600 Series makes it simple to test a battery in a minute or two. Whether you haven’t seen the customer’s vehicle in a year or two or it was in for service earlier in the week, it’s a commitment to test every battery, no matter what. Here are seven reasons why it’s important.

State of health can’t be predicted

A good battery today doesn’t guarantee its condition in a week, a month, or a year. Virtually every repair shop will have stories of a new car battery sold or installed that had to be warrantied immediately or shortly after. Even with the highest manufacturing standards in place, batteries are still susceptible to failure.

A battery test on the customer’s visit pre-road-trip might show no issues, but their service visit upon return could have markedly different results. Because you simply can’t know usage, environment, and other factors, it makes sense to just run the test on every visit instead.

It can detect an electrical issue early

Batteries are just one component in a complex electrical system. There can be much more going on than meets the eye, even when symptoms aren’t immediately noticeable. An improperly wired accessory or a short in an electrical circuit somewhere could plague a driver for weeks, months, or years, meaning they don’t trust their car.

A battery test in a situation like that might return a result like “SYSTEM NOISE CHECK LOADS” on the display, signifying the possibility of computer or ignition noise, or a problematic parasitic drain. Testing can detect the issue early on, allowing for a timely fix.

State of charge doesn’t equal capacity

As a battery is used – whether it’s an AGM, SLA, or Li-Ion battery – its capacity diminishes over time. capacity loss can be pictured like a cup that normally can be filled completely with water. But if a solid substance takes up half the cup’s volume, the capacity is cut in half. Still, the cup is full, even with only have the amount of water in it.

In the same way, a battery can have a full charge with diminished capacity. It’s difficult to test for quickly, but near the end of a battery’s life, it can sometimes show up. With battery testing during every visit, you may be able to detect diminished capacity before outright failure, even while the charge is 100%.

Sulfation could have formed during storage

Time doesn’t treat batteries very kindly, especially during periods of unuse. Sulfation is a major contributor to diminished capacity in sealed lead acid batteries that’s normally caused by undercharging, storage at high temperatures, long stretches where the battery doesn’t go through the charge-discharge cycle, and storage without being fully charged first.

Sulfation can be reversed if it’s detected early enough, and a battery test can show signs of sulfation. Voltages of a fully charged battery that show less than the normal 12.6 volts might be a clue that sulfation is taking hold.

Dead cells can occur in an instant

Every technician in northern climates has seen the bulged cases from frozen car batteries. Off-roading enthusiasts can experience sudden no-start conditions with no previous signs too. Testing reveals voltage much less than normal, usually less than 11V indicating the battery has a dead cell.

If a depleted battery is allowed to freeze, it’s highly likely that the battery will have a dead cell. The same can occur from aggressive jostling, the likes of which you’ll have from rock crawling and other forms of off-roading. Consumers can be quite upset that the condition wasn’t caught on a service visit, but a battery test from their most recent visit can show that the battery had no issues at the time, removing any onus from the shop.

Summer is as hard on batteries as winter weather

As much as we know that cold weather stretches the limits of cold cranking amperage, summer weather can be just as tough on batteries, if not more so. That’s evident from average battery life actually being longer in the northern states than in the south – 58 months compared to 41 months, according to AAA. Higher temperatures accelerate failures inside the battery.

Rather than just implementing a cold-weather strategy for battery tests, shops can catch failing batteries year-round when testing is performed on every visit.

The consumer has peace of mind

Perhaps the most important part of testing a vehicle’s battery every time it comes to the shop is the benefit for the driver’s confidence. Whenever they arrive at the service department, they watch a technician or support person lift the hood, connect the tester, and print off the results. That consistency of service as part of vehicle check-in speaks volumes toward building trust with the driver.

When vehicle owners trust the repair shop, they’re more willing to open their wallets for other services and repairs too. A free battery test in the service drive can serve to drive additional sales indirectly.

Of course, there’s also the requirement to document a failed battery for warranty purposes. Whether its for warranty compliance, customer satisfaction, or boosting your service sales, testing every battery that comes through the door is important.

What that looks like may vary. It could be at check-in by a service advisor, by a lot attendant performing a walkaround, or by the technician while in the shop. What matters more is simply putting it into practice.