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Are Semi Truck Batteries Deep Cycle? (Explained & Solved)

One of the job descriptions of a truck driver is to deliver goods and cargo on time. This task would be difficult to realize with an unreliable battery.

To prevent any contingent event from happening, perhaps a truck should be installed with a deep cycle battery.

In this article, we’ll dive into the world of deep cycle batteries. From its purpose, and size, to maintenance, and most of all, if they are installed in semi trucks.

Here’s a quick answer as to whether Semi Truck Batteries are Deep Cycle:

Most semi trucks especially working trucks are equipped with deep cycle batteries. However, there are other vehicles like dump trucks and line hauls that use starting batteries. But when these trucks have to perform extensive work, the starting battery is usually replaced with a deep cycle one.

Are semi truck batteries deep cycle?

Deep cycle battery is a marathon runner in the auto-battery industry. Rather than providing the truck lots of power, it provides lesser power but for a longer period of time.

Have you seen the words AGM, FLA, VRLA, or GEL in your semi truck’s battery? Well, these are types of deep cycle batteries.

While they are all deep batteries, they don’t offer equal performance.

For instance, AGM batteries are the most superior of all deep cycle batteries. It requires no to little maintenance, provides top-notch power, and is more technologically advanced.

Moreover, if you haven’t seen the above words in your vehicle’s battery, chances are your semi truck is equipped with a starting battery.

If this is the case, don’t fret. Manufacturers have reasons for that. After all, these batteries are all great for hauling, towing, deliveries, and construction.

It just happens that deep cycle batteries are more helpful on what a semi truck is meant for. 

After all, semi trucks are usually used for a long period. Hence, they also need a longer supply of power.

This kind of feature is the big advantage of a deep cycle battery as compared to its counterpart.

Are Deep Cycle Batteries Good for Semi Trucks?

Deep cycles are good for semi trucks. 

Deep cycle batteries are neither too low nor too much for a semi-truck.

Unlike a starting battery, as the name suggests, is only designed to give stronger power to crank start an engine.

Deep cycle batteries, however, are just enough to deliver life when your semi truck needs it most. It provides steady power for an extended period. 

Hence, there’s nothing to worry about when traveling long distances because deep cycle batteries got your back.

Can you Use Deep Cycle Batteries as a Starting Battery?

You can use deep cycle batteries as a starting battery. In fact, this is a common practice in the automotive industry.

This is the best thing about deep cycle batteries. You can use it for a dual purpose. 

However, you have to be mindful of the Cold Cranking Amp (CCA) of the deep cycle battery. The CCA rate of a deep cycle may not be sufficient to start an engine. 

To match the CCA rate of a starting battery, it is better to upsize the deep cycle battery to 20%.

What are Deep Cycle Batteries Used for in a Semi Truck?

The purpose of deep cycle batteries is to give your semi truck steady power. It can be repeatedly recharged or discharged without hurting your semi truck. 

This is the total opposite of a regular battery or starting battery. A starting battery is designed to burst enough power to start a vehicle. 

Unlike deep cycle batteries, starting battery must be fully charged and not be cycled. Otherwise, the battery may be damaged.

Deep cycle battery provides top-notch reliability for towing, hauling, and commercial trucks. It gives more power than a regular battery.

It can withstand extreme road conditions and temperatures.

How to Size your Deep Cycle Battery for a Semi Truck?

Installing an incorrect battery size will not do any good. It is a waste of money, and worse, may damage your semi truck.

Besides that, when a battery is too small for the semi truck, it will not run in accordance with its intended load. However, the oversized battery will never be fully charged. 

Check the semi truck’s manual to determine the appropriate battery size for your truck. The information you need can be found through the manual’s battery section.

You can also consult the truck manufacturer or battery retailers if you have no access to the vehicle’s manual. 

How to Charge Deep Cycle Batteries in a Semi Truck?

There are a lot of ways to charge your deep cycle battery. You can use a battery charger, solar charge controllers, or a vehicle alternator.

Deep Cycle Battery Charger

If you have an extra budget, buy a smart charger. It will not only be good for your deep cycle battery but it works on all types of car batteries.

It detects which type of battery you have and the battery rating it needs.

Smart battery discharge itself when needed. It reduces battery temperature thus preventing the risk of overheat. 

But of course, you can also use the battery charger that comes with your deep cycle. Just make sure that the charging current is 10% to 30% of amp hour.

Solar Charge Controllers

If the semi-truck is often on the road or away from main power, it is best to invest in a solar panel. It is cost-effective and convenient for you and the truck driver.

The solar panel will charge your deep cycle battery through the energy it got from the sun. To do this, the battery must be attached to the charge controller also known as the solar regulator.

Vehicle Alternator

Vehicle alternator must be your final card when the previous two options are not available. This is because the alternator is meant for AGM and Lead Acid batteries. 

If your deep cycle battery is not AGM or Lead-Acid, the alternator may not fully charge the battery.

Take note that using a non-fully charged battery may cause damage to your deep cycle.

How Long do Deep Cycle Batteries Last?

Oftentimes, deep cycle batteries can last up to three to five years. Of course, this depends on how they are used, driving habits, weather conditions, and maintenance.

Most importantly, the way you charge the battery will have a serious effect on the battery’s life.

In particular, you’ll get to shorten its life when you use it the way they are not designed for. (i.e. only using it as a starting battery)

Knowing when it will fail is difficult to determine. Even so, you can look for some warning signs such as electrical issues, slow-starting engines, aging, and corroded terminals.

How to Care for Deep Cycle Batteries in a Semi Truck?

One of the biggest perks of deep cycle batteries is that it requires little maintenance.

Nevertheless, it should not be taken for granted as the tiniest maintenance can prolong the battery’s life.

Besides proper storage, the best and easiest way to maintain its life is through proper charging.

Make sure that the battery is fully charged each time you’ll use your semi truck for the day.

Your charging routine may either make or break the battery’s life. Typically, the charging time mostly lasts up to 12 hours. 

It is recommended that you charge the battery overnight before using the vehicle the following day. This method is called slow charging.

This will keep the internal components of the battery healthy.

Check this cool video below for tips on how to make your AGM deep cycle battery last longer:

What are the Best Deep Cycle Batteries for Semi Trucks?

While the market offers a variety of deep cycle battery brands, most of them are only fabricated by manufacturers.

Hence, the need to be wise when choosing the best deep cycle batteries.

Ideally, you should follow and buy the battery brand which is recommended in the semi truck’s manual. 

But if you think that it’s beyond your budget, then it’s time to look for the best deep cycle batteries for value.

Be sure though that the one you’ll buy will meet the specification requirements provided in the vehicle’s manual.

While you may be tempted to buy the most affordable brand, this is not advisable. 

Cheaper batteries may save you more money now but they will cost you more in the long run. They often have defects that may lead to replacement and repairs.

Meanwhile, in no particular order, these are the best brands available in the market: Everstart, AC Delco, Excide, NAPA, Duralast, Odyssey and Optima.