Battery technology is constantly evolving. While a majority of batteries in operation are lead-acid of some type — and the proposed Lithium-Ion battery revolution has a long way to go in terms of development, testing and implementation — rest assured there have been vast improvements over the last decade with regards to how batteries are designed and function.
Where Are We Now?
When it comes to batteries, the general trend through the previous decades was one of using expanded metal grid technology, also known as a “framed grid.” This led to improvements in overall performance, including a reduction in the number of grid wire shorts and grid growth, a more efficient conduction of electricity from the bottom of the grid to the top and plates that are more resistant to bending. These improvements help create a more reliable and longer lasting battery.
“What has been enhanced is basically the grid structure and how you attach the lead plates to the grid which makes the energy flow more efficient,” says Thomas Winter, global marketing director, batteries for Robert Bosch. “You can also enhance the technology of the terminals, the melting of the terminals so that you don’t have too much corrosion, the thermal ceiling of the box lid can be improved so that you don’t have leaking batteries anymore. Most manufacturers today use calcium-calcium to avoid the waters going away inside the battery which makes the battery fail [prematurely].”
Improvements in light vehicle designs have also allowed for enhancements in battery design.”
ACDelco, an aftermarket as well as an OE parts supplier for General Motors, explains one such example:
“Another change, very recent to GM, is a reduced emphasis on cold cranking amperes (CCA) and more emphasis on ampere-hours or reserved capacity. There is a large opportunity in the reduction of no-starts as the consequence of drained batteries,” says David Kerr, product engineer, batteries for ACDelco. “There are demonstrated examples of vehicles requiring less CCA, but at the same time there’s only so much you can put in the battery box. We have taken that reduction in CCA and translated the lead into increased reserved capacity.”
The latest evolution in lead-acid battery technology is the AGM (absorbent glass mat). While your customers will likely pay a premium for this type of battery, the advantages alone outweigh much of the cost. How an AGM battery works is the traditional plate design is replaced with a sleeve design in which the battery’s acid is now more firmly and evenly held to the grid. What happens with a conventional lead-acid battery is the density of the acid is higher at the bottom of the battery than on the top because of gravity. The sleeve inside the AGM battery makes the contact to the plates more even. As well, an AGM battery does not have to be overfilled with acid (as is the case with traditional ‘flooded’ or ‘wet’ batteries) to ensure that acid is evenly distributed. The sleeve brings the added benefit of allowing more lead to be put into the battery case and thereby allowing the battery to produce more power.
“An AGM operates in the similar manner except instead of having a plastic separator between positive and negative [plates], you have a uniquely-engineered fibreglass mat. This mat acts both as the separator and as a reservoir for the acid,” continues Kerr. “Instead of the acid moving freely through the battery, the fibreglass acts as a sponge for the acid and as the insulator between the positive and negative.
“This technology has been demonstrated to be more resistant to heat cycles, more resistant to the cycling (to repeated events of low states of charge), it’s also shown to have resistance to vibration because the cell is now very tightly packed. One of the advantages of AGM batteries is they’re more spill proof. You can mount them on their side or upside-down without the consequence of lead-acid spilling out the vent.”
Where Are We Headed?
It is important to make distinctions when discussing battery technology in hybrids. A ‘mild’ hybrid, for instance, is a vehicle that is heavily dependant on a gasoline engine, and a ‘full’ hybrid or ‘heavy’ hybrid, such as the much anticipated Chevrolet Volt, is able to move forward through sole use of the electrical portion of the drivetrain.
“The energy pack for both the ‘mild’ and the ‘full’ hybrid requires high-level technology. Nickel-metal hydride (NiMH), Lithium ion (Li-ion), all of these types require a higher energy density, how much energy can you get within a pound of weight in the vehicle or within a given amount of space within the vehicle,” says Rick Adams, senior product manager for ACDelco.
With today’s new Hybrid Electric Vehicles (HEVs), that use a gasoline and electric engine for power, batteries are required to operate in a partial state of charge (PSOC). A partial state of charge means that the batteries need to have the ability to quickly accept and deliver power without affecting its life or performance. East Penn is on the forefront of advanced lead-acid battery technology, like the UltraBattery, that is designed to operate at a partial state of charge and deliver maximum performance.
“The UltraBattery design enhances the ability of a battery to accept and deliver high levels of power with low levels of electrical resistance similar to a super-capacitor,” says Shaun Keogh, vice-president of business development for East Penn Canada. “Traditionally, super-capacitor and lead-acid batteries are separate components relying on electronic controllers and complex algorithms to switch power between both units. This new technology eliminates the need for additional electronic control and multiple energy storage devices.”
While hybrid battery technology right now is proprietary to each OEM and has not made its way into the aftermarket, it won’t be long before those hybrids released four to five years ago will soon come off their dealer warranties.
“There’s the OES world (original equipment service) which we rationalize as being the warranty world. We have not yet matured beyond that point to develop a true aftermarket business model for the hybrid product,” continues Kerr. “The engineering and vision going forward falls entirely within the OE engineering group. Given their fairly long warranty period, the needs of the various hybrid customers are currently being met by their own unique OE manufacturer.
“Hybrids sold six and seven years ago are just coming off warranty, so it will be interesting in the very near future when customers of these vehicles have to do their own first replacement outside the warranty coverage, because right now it is our understanding that the only option is to go back to the dealership.”
Last year, AC Delco expanded its Power Sport line of batteries from 12 parts number to 23 parts numbers to include ‘flooded’ as well as AGM-type lead-acid batteries for the ‘other’-motive segment of the market (e. g. ATV, skidoos, motorcycles, etc.). ACDelco warrants to the original retail purchaser a new replacement Power Sport battery for six months from date of purchase (three months free replacement) when used in a personal powersport application.
Bosch recently launched its new comprehensive battery program in North America with the introduction of three new passenger vehicle lines and a high-tech AGM passenger vehicle line for extreme conditions and start/stop applications. The new passenger car batteries include the Bosch S5 premium performance battery, the S4 quality performance battery, the S3 value performance battery, and the S6 high performance AGM battery.
East Penn Canad a offers two Duracell Automotive Battery lines to suit different needs of the auto enthusiast: Duracell AGM with Extreme Power and Duracell EHP Advanced Generation batteries. Duracell AGM batteries feature AGM technology to deliver two times the durability, dependability and long lasting high performance to withstand the demands of multiple accessory loads. The Duracell EHP Advanced Generation batteries are specially designed to safeguard against damaging temperatures that can decrease battery life.
Last August, CAA South Central Ontario (CAASCO) launched its CAA Green Power Battery made with recycled lead and plastic, making it the first eco-friendly car battery. CAA Green Power Batteries are backed with a competitive six-year warranty that includes a free replacement guarantee in the first three years. The batteries have a defect rate of less than two per cent.