Automotive batteries are working harder than ever before.
It used to be automotive batteries had to support only a few things, for example, starting the vehicle to powering the headlights and the car radio. Everything else was mechanical and required no electricity. Today, even the simplest things require electricity, from the systems to lock and unlock a car door and raise and lower the windows, to operating an ever widening array of onboard electronics, solenoids and ever more advanced navigation and entertainment systems that are becoming standard on a growing number of vehicle makes and models.
This has spurred new advancements in battery technologies in order to meet the electrical needs of today’s vehicles, which now require much more power to successfully operate in today’s vehicles than years previous.
“A number of years ago, General Motors and ACDelco stopped using maximum CCA as the benchmark for battery performance,” says David Kerr, ACDelco senior battery engineer for General Motors Customer Care and Aftersales. “Instead, we began to specify batteries with the right CCA, but increased reserve capacity [RC]. Increasing RC gives the customer more key-off energy [fewer no starts due to run down battery] and also allows the battery to be maintained at a higher state of charge on an ongoing basis [less deep cycling leading to battery wearout.]”
Shaun Keogh, vice-president of business development with East Penn Canada, says that with today’s vehicles needing more power and batteries having to fit often into much tighter engine compartments, battery makers like East Penn have begun moving to new kinds of battery designs.
“The consumer driving experience continues to expect increased electrical functions and features, which forces vehicle electrical systems, and the batteries that help power them, to become more durable and efficient,” he adds. “The automotive industry is on an upward trend toward the use of AGM [Absorbed Glass Mat] products as a vehicle’s original equipment battery. AGM technology adds additional durability to the battery’s design to enable it to last longer under less than ideal circumstances and demanding accessory loads. This helps accommodate complex vehicle electronics and the demand they put on the battery.”
ACDelco’s Kerr says his company has also transitioned to new battery technology to meet these issues.
“Most recently, ACDelco has supported the transition to AGM batteries as a replacement for OE batteries and as an upgrade for OE flooded batteries. AGM batteries can withstand many times the deep cycle events and be maintained at a lower state of charge without damage [sulfation]than a flooded battery. AGM batteries have the durability to handle the frequent key-off loads that are part of the new Start-Stop fuel savings technology. Flooded batteries are not able to withstand this environment.”
While today’s battery technology can provide more power and work more efficiently in harsher vehicle environments, that does not mean that they still don’t suffer failures. Technicians still need to keep in mind that batteries can fail for reasons that have nothing to do with age.
East Penn Canada’s Keogh says sometimes it can be something as simple as an accidental power drain, such as leaving on the headlights or interior dome lighting and thereby draining the battery. “Draining the battery to a very low state of charge can do permanent capacity damage.
“Another common cause of battery failure is putting the wrong battery in the wrong application,” he adds. “For instance, if the vehicle requires a certain amount of starting power, installing a battery that isn’t designed to provide that much starting power will quickly wear it out to the point of a no-start situation. Also, if the battery’s dimensions don’t align with the vehicle’s recommendations, it might not have a good fit and suffer damage from vibration or clearance issues.”
“The primary cause for battery failure is wear out,” says ACDelco’s Kerr. “Wearout can occur over years of use while a battery goes through its normal life of being charged and discharged. Corrosion of the plates inside the battery leads to weakened grids and active paste falling off the plates. The battery slowly loses power and eventually is no longer strong enough to start the engine because the active paste and electrical pathways designed into the battery are no longer functioning.”
One thing that can shorten the life of a battery is if a technician makes an error in charging the battery during a service visit. Domenic Ninni, senior technical specialist and industry consultant with ACDelco says these are common mistakes that can be made:
Incorrectly determining the battery state of health before charging — which will ultimately determine if the battery should/can be charged and will help establish the minimum recharging requirements.
Incorrectly determining the battery state of charge (or discharge) before and after charging — incorrectly determining the battery is ‘fully’ charged and ready to be put into service.
Limited understanding of battery and charging technology.
“All of which leads to batteries being incorrectly recharged, either over-charged or under-charged,” Ninni continues. “Trying to recharge a ‘bad’ battery that is shorted/open or unable to accept a charge; recharging a battery at 100 amps for 20 minutes thinking ‘that should do it;’ or trying to let the vehicle’s alternator recharge the battery by ‘driving it.’”
East Penn Canada’s Keogh adds that under normal conditions, “a properly functioning alternator will recharge the battery. However, a discharged battery should be tested to make sure that the alternator wasn’t the problem in the first place. Without testing the battery, there’s no way of being sure that the battery will even take a charge. It is also possible that the vehicle’s alternator is faulty and it will not charge the battery. In that case, it wouldn’t matter how long you ran the vehicle, it would not charge properly. Regardless, testing the battery and charging it outside of the vehicle, especially after a no-start situation, is always the safest measure.”
When it comes time for charging a battery ACDelco’s Ninni says making sure one has modern testing and charging equipment is a must, as many of today’s systems are designed to take the guesswork out of battery maintenance.
“Since the battery charge rate, length of time required and the type of charge cycle for optimum battery charging is determined by the manufacturer and the battery design, technicians should always consult their service information regarding the battery and system they are working with,” Ninni adds. “This information will provide the guidelines required to accurately and effectively charge a battery.”