Auto Service World
Feature   April 1, 2008   by Philippe Gauthier

Where Does The Battery Maintenance Market Stand?

In North America today, the three major automotive battery manufactures are focusing their energies on ever-improving the technology of their "maintenance free" batteries. These batteries offer a vari...

In North America today, the three major automotive battery manufactures are focusing their energies on ever-improving the technology of their “maintenance free” batteries. These batteries offer a variety of advantages to drivers. Only for a customer to get the most out of these batteries, they need to know a little bit about the different kinds of “maintenance free” available and how they work; and technicians need to know how to best keep them running properly so that customers get the most out of their investment.

What exactly is A “maintenance free” battery?

“Maintenance free” batteries come in three varieties: antimony batteries, calcium batteries and mixed calciumantimony batteries. Antimony batteries dominated the market a few decades ago. Today, most are hybrid calciumantimony designs which are chemically more stable, emit less gas and absorb less water.

Calcium-antimony batteries keep their load for a long time and are often the first choice for new vehicle manufacturers. These batteries remain, however, more capricious to reload under severe discharge and a completely reloaded battery can even display some sulphating.

There is also another style of “maintenance free” battery, the VRLA (Valve Regulation Lead Acid). This kind of battery is characterized by the quick recovery of escaping gases — mainly hydrogen and water — and recombining them into water. VRLA batteries also come in two main types: gel batteries and AGM (Absorbed Glass Mat) batteries. In gel-based batter- ies, silicones are added to the liquid acid making the acid have more of a gel-like composition. These batteries never leak, are very robust, display outstanding capacity and will resist severe discharges as well. However, they will have a hard time dealing with energy peaks, such as in high-demand engine start-ups. Because of this drawback, these gel batteries are more likely to be found in golf carts than in today’s automobiles.

AGM-based batteries are more promising for the auto industry. The new Mazda Miata comes equipped with such a battery. What is unique about AGM-based batteries is the lead plates are not immersed in a free acid solution, but rather intertwinned between layers of acid-filled, thin fiberglass. These batteries will resist vibrations, while the low resistance between plates can deliver large currents, thereby providing tremendous starting power. On the other hand, they generally contain little acid and will not resist sulphating for long, and they must also be carefully recharged because they are sensitive to voltage leaks.

At Exide, this product is sold under the name Orbital battery brand. The battery looks like a large Lego block and is made up of six interconnected cylindrical cells. Each cell is not made of parallel lead plates as in conventional batteries, but contains a spiraled lead plate, rolled up and with a glass-fibre blotter. This glass-fibre blotter helps prevent leaks as all the liquid is retained by the blotter. The battery is also designed to withstand repeated vibrations, like what is encountered in extreme cross-country driving and which would normally break most regular battery plates.

Maintenance of “maintance free” batteries

Because we don’t have to measure such things as electrolyte levels and then add liquid as was once done with older battery types, today’s batteries are now tagged as “maintenance free.” However, “maintenance free” misleads many into thinking these batteries can be installed and forgotten. Indeed, keeping today’s new batteries operating properly and at peak performance starts right at the time of installation. A loosely attached battery will soon die. Even a small pothole will make the battery jump, and a severe bump or shakeup can end up breaking lead plates. Whenever two plates touch, a resulting short will definitely scrap the battery. On the other hand, one should not screw the battery in too tightly as too tight of a fit can split the battery housing and cause leaking of its acid.

Another neglected aspect of battery maintenance is cleanliness. The space between the two terminals must be free of dust because whenever the battery is heating, a little sulphuric acid escapes from its vents. The acid will mix with dust which then forms a conducting medium between the two terminals.

Over time, this will cause the battery to discharge, something a technician can see with a simple DVOM.

Seasonally stored vehicles such as sport cars or motorbikes should get their batteries charged three times if they are stored for some six months or more. First, when the battery is withdrawn from the vehicle when it goes into storage, second, half-way into winter and finally, right before the battery is reinstalled for summer. Recharging must be done at room temperature.

Life and death of a battery

Batteries will die in either very hot or very cold weather. During heat waves, for example, when a car is stuck in heavy or even stalled traffic, the underhood heat gets very high. Add to that the often poor ventilation of the underhood area, what one discovers is the alternator slowly begins to idle and produces little current. This soon causes the battery temperature to increase which makes the internal battery acid get more aggressive on the plates. Add to that the demand of the A/C system and the load of other car electronics, and soon the battery reserves will be overtaxed. When that happens, the battery acid will start to boil and attack the battery’s internal components, reducing the battery’s capacity even more. This quickly becomes a Catch 22 situation, where the battery overheats to produce all that needed power during hot weather and becomes exhausted in the process. It may not die immediately, and the battery may last for the rest of summer. But as cold weather approaches, the battery’s reduced capacity will become obvious as one day it will fail to start the engine. A pre-winter visual inspection will reveal such a risk to the technician, and an “overboiled” battery will usually display slightly convex or bubbling sidewalls.

Occasional freezing cold weather will not damage the battery directly. However, deep freezes can pose problems. In cold weather, one needs more energy to start the engine. Repeated starting in very cold weather soon exhausts the battery. On frequent stops and starts, the battery will become insufficiently charged and will soon die.

This problem is particularly frequent with fully equipped, gadget-heavy cars if they are mainly used for short trips. A German manufacturer reported on 100 supposedly defective batteries, 50 are actually working perfectly and only seven per cent could be classified as being defective from a manufacturing standpoint. It seemed all of those gadgets are indeed energy hogs. Ordinary cars will also suffer from this problem, especially if they are used for short trips, night driving or driving in bad weather where there is a heavy demand placed on the battery in the near constant operation of the headlights and wipers etc. One thing that has to be remembered by technicians is that the usual load tests may mistakenly suggest that a battery is ‘dead’ when it is in fact still good. So technicians have to be careful not to declare a battery dead before its time.

Winter starting

A stalling engine does not always mean the battery has to be changed. Just put your palm on the positive pole. If it happens to be warm, the battery is displaying current, but the contact is defective, dissipating energy over parasitic resistance. A blade screwdriver properly inserted between the pole and the attachment will confirm this diagnostic as the engine will start. Battery poles must always be tightly attached to the main wiring and display no sulphatation. Another easy test is to turn the lights on. If they display normal brightness, chances are the battery is still OK.

To avoid surprises, load tests are necessary before winter arrives. This is a technician’s best t
ime to sell a replacement battery to the customer.

Finally, if there is a current leak, there is only one way to address the problem and that is with a DVOM. Just measure the leak and unplug the fuses, one after each other. When there is suddenly no current leak, well, the faulty circuit has been disconnected. Then you can figure out how that happened, such as if the customer has tried to install an audio system themselves.

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