Figure 1. The relationship between specific gravity (SG) and open circuit voltage (OCV).
The service vehicle is an important tool. Without it, a technician may be unable to get to the jobsite.

The service vehicle also represents a major investment, and is likely one of the single largest investments you make. If the vehicle is down for any reason, the results could be very costly.

In order to maximize vehicle usage, there are a number of things you are likely already doing to keep the vehicle running. Looking beyond gas, oil, and tires, there is one very important component in your vehicle that is usually taken for granted until it fails: the battery.

When batteries fail, they seldom give much of a warning, if any at all. However, you can inexpensively maximize battery life and reliability. Doubling remaining battery life is not out of the question. Neither is getting 10 years of service out of a brand-new battery.

The Problem With Batteries

The unfortunate thing about a battery is that any use is bad for it. From the very first time you draw current from it, the battery begins to deteriorate.

A lead-acid battery uses a chemical process that creates electrical energy. As current is drawn from the battery, sulfur ions are taken from the weak sulfuric acid and deposited on the lead plates. As the available number of sulfur ions drops, the battery enters a discharged state and requires charging, which is why there is an alternator.

In a perfect world, these deposits would be removed during the charging cycle, returning all sulfur ions to the acid. In the real world, this does not happen. Some deposits remain on the plates no matter how long or how much the battery is charged.

Over time, the deposits build up and eventually insulate large portions of the lead. This insulation, in turn, prevents the battery from conducting sufficient current to start the engine.

The economic impact of this can be startling. The World Battery Council estimates that more than 80% of the lead acid batteries scrapped each year have excessive sulfate deposits that have rendered the battery useless.

Pulse-Width Charging

There is a relatively new technology available that can be used to remove these sulfate deposits and greatly enhance battery life and durability. The technology is known as pulse-width charging.

A simple and inexpensive pulse charger is added directly across the battery terminals and left there on a permanent basis. The pulse charger then utilizes the existing 13.8-vdc (nominal) charging voltage to generate high-frequency pulses which are sent into the battery to soften the deposits, causing them to be released from the surface of the lead and return to the acid. As the sulfur ions return to the acid, the specific gravity (SG) increases, which in turn raises the open circuit voltage (OCV) of the battery.

In addition, as the battery plates become cleaner, more current can be drawn from the battery. This would tend to boost the cold-cranking ampere and the cranking ampere ratings of the battery. Figure 1 shows the relationship between SG and OCV. By properly selecting the pulse frequency, the impact on the battery can be optimized.

Over the past few years, different techniques have been tried with varying results. Earlier techniques allowed the battery to be in control of the process, while the latest technology allows the pulse-width charger to control the process, greatly enhancing performance. Using this technology has demonstrated measurable results in as little as a few charging cycles.

Economic Impact

Pulse-width charging increases battery life and helps the environment, as fewer lead-acid batteries are being scrapped.

It is to be expected that the battery manufacturers will claim that their batteries don’t need this technology, since all they want to do is sell more batteries. As noted by a frequently watched network news anchor, “It’s your money.”

For less than the cost of dinner for two, this particular sulfate-accumulation problem can be eliminated.

However, I want to be very clear: There are other problems that can crop up in a lead-acid battery. The second most common problem is mechanical failure. The pulse-width charging technology addresses 80% of the annual battery failures.

The Acid Test

Although many batteries can be recovered, some may be too far gone to be salvaged.

A good rule of thumb when evaluating a battery is to do an acid check. If there appears to be an adequate amount of acid still in the battery, then there is a good chance it can be recovered.

If little or no acid exists, just replace the battery and protect the new one with a pulse-width charging system.

Although battery failures may not happen all that often, they always seem to happen at the worst possible time.

Loss of income from a single dead battery will cost more than adding pulse technology. Give it a try.