A battery is a battery, is a battery, correct? Unfortunately, that is not the case. Batteries come in a multitude of sizes and classifications. With so many variances between batteries, it can be confusing when it’s time to choose. For instance, when selecting which battery is best for your application, how many cold cranking amps (CCA) are actually required, are they really that important, and what are amp hours (Ah)?

What Started This Discussion?

When it was time to replace the batteries in Project WorkHorse, I had those very questions that needed to be answered. Also, I knew I wanted a battery that could deliver all the juice I need, and last more than just a year or two. The heat in Florida can wreak havoc on a cheaply made battery, and I have always had good luck with Optima batteries, so that decision was easy. I looked at the Optima website and only found one battery that was designated for my 2019 Cummins-powered Ram — the YELLOWTOP DH7.

This is a deep-cycle battery that offers three times the service life of a traditional flooded lead-acid battery. To get some insight about this option, I reached out to Jim McIlvaine of Optima Batteries. When it comes to batteries, Jim is the go-to guy for information.

Finding the right battery for your truck is as easy as looking it up on the Optima Batteries website.

Unlike a truck with spark plugs, diesel-powered rigs like WorkHorse require two batteries. The upside to that is easy starting and a large electrical capacity. The downside is, there are two, which can get expensive when it’s time to replace them. And yes, I said them, because it is never a good idea to only replace one.

“Whenever two or more batteries are used in an application (series or parallel), they need to be identical in age, size, and type,” Jim stated. “Older batteries have more internal resistance, which makes it harder for them to accept and deliver current. That means if you connect a new battery with an old battery, the new battery will deliver more current, get worked harder, and probably be overcharged, while the charging system tries to maintain the older battery in the same string.”

If you live in a climate that doesn’t get frigid temperatures, CCA is not as important as Ah. If you live in a climate that gets very cold, CCA is your friend.

Jim continued. “The same thing is true with batteries of different sizes. The smaller one will get worked a lot harder and probably overcharged while the bigger one may never get fully charged.”

Also, it is not a wise to mix different types of batteries. This is because a lead-acid battery has more internal resistance than an absorbent glass mat (AGM) like an OPTIMA batery. What ends up happening is folks find themselves replacing the one bad battery in that application more frequently because of the unbalanced use, than if they would’ve just replaced two at the same time.

Getting the driver’s side battery out of a fifth-gen Ram is not hard, but once you remove the fender bracing, disconnect the cables and the hold down, you gotta lift that sucker out of there. The old battery came in 52 pounds.

That doesn’t mean you have to get rid of the one good battery from the old set of two. It might still deliver several great years of service in another application, but it should no longer be used in a multi-battery scenario. You’ll never be able to pair it with another matched battery, even if it’s the same size, type, and age because the two batteries weren’t used in the exact same application before and there’s no telling what the condition of the batteries are relative to each other.

Which Battery Delivers What Your Truck Needs

When asking which battery is best for your truck, you need to look at certain attributes a battery possesses. For instance, while you are worried about cold cranking amps (CCA), you might really need to focus on amp-hours (Ah). And what is a reserve charge (RC)? Jim enlightened me on what’s important, and to whom.

“It depends on what you’re doing and where you live,” he said. “For example, no truck owner in Florida needs to think about cold cranking amps, because it never gets below zero there. For someone with a diesel truck in Alaska, it would be a far more important consideration. Generally speaking, as long as the battery meets or exceeds the engine’s cranking requirements, there’s no need to go chasing a big cold cranking amp number, especially if the vehicle doesn’t see much cold weather use.”

Before installing any new battery(ies) make sure they are at a full charge and then clean both the battery post and the terminals. Also, a little dielectric grease on the posts is a good idea.

Why Amp Hour Matters

“Ah or RC rating has become a bigger consideration in modern vehicles because of how much energy they consume when the engine is turned off,” Jim stated. “It’s really more about the reserve capacity in these modern vehicles.”

A battery’s reserve capacity is the amount of time, measured in minutes, that a 12-volt battery can run before dropping to 10.5 volts. It is measured in reserve minutes. For example, if a battery has a reserve capacity of 150, that means it can supply 25 amps for 150 minutes before the voltage drops to 10.5 volts.

“Between OnStar, integrated anti-theft systems, Wi-Fi, and a host of other electrical accessories, demand on batteries has never been higher,” Jim stated. “The more deeply you cycle a lead-acid battery, the fewer cycles you’ll get out of it, so automakers have moved to physically larger batteries to get more life out of them, hopefully past the period of free warranty replacement.”

Optima designs its battery to fit like OE. All connections return to the way they were with the old battery.

Sizable Concerns

In truck applications, as long as you are covered on cranking requirements for the engine, Jim says the best number to look at is the battery’s weight. I know what you’re thinking, “what does a battery’s weight have to do with starting my truck”? Different battery brand manufacturers can be more or less aggressive in how they rate their batteries in terms of the specifications.

“There is no fudging the numbers when it comes to a battery’s weight, and heavier batteries generally indicate more plates, more active material, and more power,” Jim affirmed. “Optima’s DH7 battery weighs 60 pounds. Other AGM H7 batteries are being sold that weigh 8 pounds less than the DH7 YELLOWTOP and there are flooded batteries that weigh 17 pounds less.”

While CCA will get you more power during the initial engine starting, Jim alluded to Ah/RC being a bigger consideration for newer vehicles. “Without getting too deep into the technical weeds, amp-hours (and reserve capacity) is a specification that indicates the energy capacity of a battery over a longer period of time, as opposed to cold cranking amps, which are measured at 0-degrees Fahrenheit for 30 seconds. A 50Ah battery will generally be able to deliver more energy over time than a 30Ah battery. I cite this number frequently when explaining parasitic draws to folks. Jim went on to explain.

“For example, in a vehicle with a 50Ah 34/78 REDTOP, if a car alarm has a key-off load of 190 milliamps, that means the alarm is discharging that battery at a rate of 4.56 amps (.190 x 24 hours) per day. That means the battery will be dead (0-percent state of charge) in just under 11 days (50/4.56) without any charge going to the battery…if the battery was fully charged when the vehicle was parked, which most are not.”

Like a glove.

Finding Which Battery I Need

For Project WorkHorse, the first thing I did was check the Optima website to see which batteries were available for my 2019 Ram. Once I input the needed make, model, year, and engine, I learned I had a single option, which made the decision easy.

The DH7 YELLOWTOP cranks out 880 cold cranking amps, but I live in Florida and that is not a real concern. However, it does offer an 80Ah rating with a reserve capacity of 155 minutes at 25 amps. What’s more, the weight comes in a hefty 60 pounds. Think about that when you have to lift it up and over the fender — twice.

Remember the old adage of you get what you pay for? Well, diesel enthusiasts have been utilizing Optima’s AGM batteries for years because they surpass other options in terms of durability, longevity, and performance. AGM batteries will not only perform better and last longer than their flooded counterparts, but their sealed design will help minimize the chance of battery acid causing damage to your vehicle. If your truck is ready for new batteries, maybe a pair of Optima batteries would be a great choice.