Cell Mates

Get the best bang for your battery buck without shooting yourself in the foot


Batteries. You don’t think much about them until they die. An avid outdoorsman and life-long pickup owner, I’ve had my share of those instances, as I’m sure many professional contractors and landscapers have over the years.

Interstate batteries are widely distributed and rotated regularly for freshness to ensure that most of their lifespans are spent under a hood rather than on a shelf. (Photo courtesy Interstate Batteries)

Pickup batteries are a crucial part to our lives and livelihood. That’s why we panic when they fail, rushing to replace them with ones that will fair better under the demanding conditions of road construction, pit and landscaping field work.

We rely on our instincts and past experience in making that purchase decision.

But with battery technology changing and new vehicle demands placed on them ever increasing, it’s difficult to know exactly what to look for in a new battery.

I’ve been writing about batteries for more than 20 years yet I still find an occasional gap in my battery knowledge. So I consulted with two experts to make sure the information you are about to read is hole-free: Interstate Batteries’ Gale Kimbrough and EnerSys’ Kalyan Jana.

Optima ACM batteries were the first to use the spiral-cell, "six-pack" design which doesn't require the addition of strengthening alloys in the plates and can use pure lead. (Photo courtesy Optima)

If you start a business selling Interstate batteries, Kimbrough will probably be the man behind the training that enables you to match customers with just the right battery.

And if you are looking for someone to help you build batteries or any other stored energy solution, you can’t go wrong turning to Jana, development support manager for Enersys, the manufacturer of Odyssey batteries.

These guys know batteries – and what’s important when it comes to batteries in work pickups.


Too many variables prevent pinpointing a “normal” battery lifespan. But personal experience, owner/dealer feedback, and input from experts such as Kimbrough and Jana indicate a battery should last between three and four years in a hard-working truck.

Enersys offers the Odytssey series of AGM batteries including top quality dual purpose models with plenty of starting power and enough cycling ability to run accessories when the engine is off without damage. (Photo courtesy Enersys)

But the length of a traditional pickup battery’s working life in heavy construction, landscaping, utilities, DOT and municipality applications depends on many factors: geography (extremely hot and cold climates reduce battery life); engine type (diesels are harder on batteries than gas); vehicle use (short engine run times between starts hammers a battery); and electrical load (accessories run with the engine off stresses a battery system) all play a role.

A lot of research goes into selecting an OEM pickup battery for a truck and it’s easy to torpedo that effort by adding aftermarket electrical/electronic loads that weren’t in the manufacturer’s calculations.


“A contractor friend bought a new one-ton truck for his business last year,” Kimbrough says. “It was loaded with factory accessories.

AGM batteries, like the Intimidator line from Deka/East Penn, includes starting, deep-cycle and dual-purpose models. (Photo courtesy Deka/East Penn)

A couple months later he added additional accessories that were being used when the truck was turned off. He lost run time on the OEM battery, discovering that if his truck sat for more than four hours at a job site the battery would barely start it.

“He was upset because he used to get three years out the batteries and now after only a few months the one in his new truck was giving him trouble.”

Kimbrough ran an electrical load test for parasitic discharge (discharge with engine and key off) on the battery and discovered his friend had increased the electrical load by 50 percent over the factory setup. The continual deep discharge when the engine was off was killing the stock battery.


Sluggish starts and reduced operating time for engine-off accessories are good indicators of a failing battery. So are physical signs such as extreme side bulging of a battery’s case, increased loss of electrolyte between normal checks, and increased terminal corrosion are signs of impending battery failure.

But the only way to be sure of a battery’s condition is to have it load-tested or checked with an electronic battery analyzer.

It’s a good idea to have a check like these done periodically even when no symptoms are present. Adding a six-month battery checkup to your pickup’s maintenance schedule can prevent a job-site headache.

Both Jana and Kimbrough warn waiting until a battery fails to replace it is never a good idea because a weak battery may be taxing other electrical components and shortening their lives as well.


How do you determine whether a replacement OEM battery is all you need or it’s time to step up to something different? Jana says a detailed cost-benefit analysis is needed to get the correct answer, especially if a fleet of pickups is involved.

Fleet managers focusing on purchase price alone can miss long-term savings because that approach overlooks the cost of labor to replace the batteries as well as costs incurred when the vehicle out of service.

Comparing the costs of routine maintenance between battery types also needs ­consideration.

The most accurate way to evaluate a battery’s condition is to have it tested by your dealer or a battery shop. Including a battery test with your regular maintenance visits can prevent problems at the job site. (Photos by Allan Tarvid)

For example, OEM-type flooded batteries are relatively inexpensive when compared to the more state-of-the-art absorbed glass mat (AGM) style. However, they are more prone to corroded battery cables and terminal lugs, regular battery-cell checks are required to make sure the electrolyte stays above their plates, and flooded batteries don’t take well to rough off-pavement driving conditions.

AGM batteries, on the other hand, are more expensive but they are more efficient, virtually maintenance-free, and tend to last longer in the harsh work environments faced by professionals.

So don’t be surprised to find your cost-benefit analysis of the ultimate work truck battery points your purchase toward a dual-purpose AGM replacement.


The terms “AGM” and “gel” are often mistakenly used to describe all sealed batteries. Both Jana and Kimbrough agreed that gel batteries are not a good choice for work trucks.

Some GMC Sierra 1500s come equipped with an empty second battery tray on the driver’s side near the radiator that greatly simplifies adding a second battery when needed.

Gel batteries are not designed to deliver the high discharge currents required for engine starting and often don’t meet the cold-cranking amp (CCA) ratings required by the vehicle manufacturer. They also require lower charging voltages than most truck alternators put out; subjecting them to higher charging voltages greatly impacts their longevity.

AGM batteries are a good upgrade replacement for stock lead-acid/flooded-type batteries; AGMs are more than up to the task of handling heavy cranking and accessory loads and work well with today’s high-output alternators.


One more factor should be considered in your next battery purchase: weather. Cold and work pickups seem to go hand-in-hand. Unfortunately, batteries don’t like the cold.

Kimbrough says a battery’s ability to operate a vehicle’s engine-off electrical accessories drops about 60 percent at 0 degrees F compared to its performance at 80 degrees F, and engine starting can demand twice the amount of cranking current at zero degrees than is required at 80.

So it’s critical to have a battery (or batteries in the case of diesels) with a high CCA and your pickup’s charging system’s health checked prior to the arrival of winter.

Jana says if cold-weather operation is part of your work routine consider upgrading to thin-plate pure-lead (TPPL) dual-purpose AGM batteries. They are designed to operate at temperatures as low as -40 degrees without any special winter care.



• Never store batteries on concrete. Kimbrough says it was true 50-60 years ago when battery cases were made of hard rubber but it’s no longer a worry with today’s Polypropylene plastic cases.

• Water that’s safe to drink is okay for batteries. The experts were divided on this topic; while manufacturers still recommend replenishing cells with distilled or de-ionized water only, Kimbrough said that good drinking water will work in a pinch. Jana suggested that tap water is never recommended and sticking with distilled or de-ionized water is your safest course.

• Add aspirin to each cell when a battery quits working. Kimbrough says all you get is a slight chemical reaction that doesn’t help. Aspirin cures headaches, not bad batteries. If the battery is bad, replace it.

• You need to fully discharge a deep-cycle battery occasionally. Not true says Kimbrough. Never discharge a deep-cycle battery below 50%.

• Lead-acid batteries retain a memory. Another dud. A lead-acid battery can neither create nor retain a discharge/charge memory.



Two important ratings come into play when shopping for a replacement battery. The first is Cold Cranking Amp (CCA). This rating tells how many amps a battery at zero degrees Fahrenheit can deliver for 30 seconds without its voltage falling below 7.2 volts. The bigger the CCA number, the greater the starting power.

Kimbrough recommends upgrading with a battery 10-15% above your vehicle’s original CCA rating in moderate to high-heat climates, higher if you work in the Snow Belt. But never install a battery with a lower CCA than your vehicle’s manufacturer recommends.

Reserve Capacity (RC) is the other important rating. RC tells how long the battery can run accessories without charging.

RC is the number of minutes a battery at 80 degrees F can deliver 25 amps without falling below 10.5 volts. The higher the RC number the longer the battery can power accessories before it must be recharged.

“The trick is to balance the CCA and RC numbers so that you can run your engine-off accessories as long as necessary and still start your truck,” says Jana. “Going cheap can result in a dead-battery service call that costs more than a better battery would have.”

Cranking Amps (CA), Marine Cranking Amps (MCA), and Amp Hours (AH are not meaningful to work truck owners who must drive in below freezing temperatures. Let CCA and RC be your buying guide.



Kimbrough suggests pickup owners follow these simple guidelines when battery shopping:

If the pickup was originally equipped with an AGM battery, stay with an AGM;

If the pickup came with a flooded battery – and it lasted two years or less – consider having a good electrical auto tech evaluate whether an extra battery (or batteries) are needed due to vehicle parasitic discharges, or switch to an AGM;

If the pickup’s original flooded battery lasted three or four years, an AGM may not offer enough extra value to overcome its higher purchase price (an AGM may cost twice as much as a flooded battery, but may not live twice as long);

If you use the pickup off-road or in rough terrain, AGM batteries stand up better to vibration than a flooded battery.



Need more battery power than your truck came with from the factory? Install a second (or third) one.

There are two ways to wire an additional battery; connect it directly to the existing battery (positive to positive and negative to negative) or place an isolator between the two.

If you install a second battery without an electronic isolator it is always best to match the existing battery’s type and power ratings. If you isolate the new addition, you can use a battery with a different size and power capability like a big marine or RV deep-cycle battery.

But Kimbrough warns against pairing AGM and flooded types because AGMs have considerably less internal resistance and current flows to the battery with least resistance first, draining the other battery.

Jana feels dual-purpose (starting/deep-cycle) batteries with high CCA ratings and good cycle life are the best answer when two batteries are wired directly together (without an isolator) to handle both starting and engine-off electrical loads.

Jana says a BCI Group 34 dual-purpose, thin-plate pure lead (TPPL) battery will deliver up to 1,500 amps for three to five seconds at room temperature for engine cranking as well as 400 charge/discharge cycles down to an 80% depth of discharge. With dual-purpose performance like that you wouldn’t need two isolator-separated batteries for starting and engine-off accessory cycling.

The lower internal resistance of deep-cycle and dual-purpose AGM batteries also spin-up starters faster and to deliver higher discharge currents to accessories like winches, work lights and 12-volt air compressors.

Kimbrough suggests that if you run multiple batteries you should make sure the pickup’s alternator has enough output to keep the batteries charged. If your truck came from the factory with an extra battery tray it may already have an optional high-amp alternator ready to handle a two-battery system (check with your dealer to make sure).