Dual Battery for Solar (Goal Zero Power Systems)

If you’re wondering if a dual-battery or Goal Zero system is the right one for you, you’ve come to the right place.

We’ll show you the ins and outs of these systems so that you can decide for yourself which one will work best for your lifestyle.

What We’ll Discuss in This Article:

  • The purpose for each of these items
  • What makes each one special and unique
  • The pros and cons of each item
  • How the items were developed
  • The main reasons for choosing each one

Dual Battery vs. Goal Zero

Let’s start by comparing a dual-battery system and the Goal Zero system. First of all, the dual-battery system is used in a vehicle; as the name implies, it has two separate batteries.

The second battery is a power source for auxiliary gear and accessories. With dual batteries, the vehicle engine runs at the same time that the starter battery works with the alternator to power the vehicle itself and the electronics.

On the other hand, Goal Zero is a solar panel that you attach to the Yeti Power Station or another power bank after the sun has harvested the energy.

With Yeti, you can store the power for later use and plug in your devices to the Yeti Power Station or your power banks.

Having a second or auxiliary battery is perfect in specific scenarios.

If you go camping, for example, you can save your main battery to keep the car from going dead and the auxiliary battery to power items such as lights, a mini-refrigerator, etc.

Goal Zero’s monocrystalline panels range in size from 5 watts to 200 watts, and if you chain multiple panels together, you get a much faster charging time.

Dual-Battery Systems

With dual batteries, a second battery is installed in addition to the original factory-fitted battery. The two batteries do not work in conjunction, and an isolator disconnects the starter battery from the secondary battery.

Power is drawn from only one battery at a time to reserve each battery’s power. Just where are the second or auxiliary batteries located?

They are usually in a dedicated space that includes a purpose-built tray in the cabin or the load space in the rear. The goal of having dual batteries is always to have readily available and consistent power.

Usually, the auxiliary battery is a deep-cycle battery because these are very inexpensive. They can also be lithium batteries, which are durable and lightweight, or AGM batteries, which are best for partial use yet let out no hazardous gasses.

See also: How Does a Solar Battery Work? An Ultimate Guide to Understanding Solar Energy Storage

The pros and cons of a dual-battery


  • Have the peace of mind knowing you have an “extra” battery on hand
  • Can be used to power lights, radios, inverters, etc.
  • Will never drain the original battery
  • Can power the auxiliary battery with solar panels if you like


  • They add weight to the vehicle/housing
  • They are not easily transported

Goal Zero Battery Systems

Goal Zero systems usually involve a lithium battery, are lightweight and offer a very long life when it comes to power storage. They can be used to power everything from smartphones to headlamps and everything in between.

One of their most significant features is their ability to charge in several ways, and several sizes of the Yeti power station are available.

The larger one comes with an AC inverter, USB-C cord, and wireless systems that are compatible with apps you can download on your smartphone.

This means that you can start using your Goal Zero system immediately after taking it out of the package.

Pros and cons of the Goal Zero Battery system


  • It is very easy to use
  • Ready to go setup
  • Built in ports for instant connection
  • It is a very sturdy system
  • It comes with a one-year limited warranty
  • The control panel is very simple to understand


  • It can take a long time to completely charge
  • It is made mostly for smaller devices

History of Dual-Battery Systems

Dual-battery systems have been around for a while but are now more sophisticated than ever.

Nowadays, they can be charged with a basic isolator, a “smart” isolator, or even DC-to-DC charging, which works similar to batteries that you use at home.

In addition, many campers and outdoor people choose a dual-battery system and a solar panel system to ensure that they always have the power they need to operate.

This is for many devices, including their vehicles, when they’re on one of their outings.

History of Goal Zero Solar Power Systems

Goal Zero began in 2007 when their goal was to help people in impoverished nations find sustainable ways to help themselves and better their lives.

In the spring of 2020, the company turned its focus to making face shields due to the COVID-19 crisis, but that didn’t stop them from improving their other products.

Today, Goal Zero makes solar panels, briefcases, power stations, solar chargers, power banks, complete kits for getting started with the system, and tons of accessories that include replacement batteries, vehicles, and so much more.

What Does the Dual-Battery System Offer?

Dual batteries are meant to last anywhere from 18 months to 3 years, provided they are well taken care of and well maintained.

And the main reasons for choosing this option are plentiful, including:

  • They optimize the power you need
  • They help guarantee that your original battery is always ready to use
  • It is very unlikely that you’ll run out of power to juice up all of your accessories

Dual-battery systems give you the extra oomph you need when you’re going to be away from home for a while and you need a reliable way to power up not just your vehicle, but also any accessories or tools you’ll need while you’re on your outing.

What Do the Goal Zero Systems Offer?

The Goal Zero solar power batteries usually have a shelf life of around three to six months, but there are replacement batteries available whenever you need an additional one.

Some of the main benefits of a Goal Zero system include:

  • They are safe and reliable
  • There are several of them to choose from
  • They are very versatile
  • They come with lots of port options
  • They are very quiet

How to Decide Between the Two Systems

By now, you’re probably wondering which of these two systems you should choose. Remember that even some dual-battery systems can be powered with solar panels, so the two systems have something in common.

Your budget is likely the first thing that you should consider when choosing between the two systems.

Dual Zero Option

If you’re on a tight budget, the dual-battery system is likely to be cheaper. That being said, if you can, you should look at other things besides the cost of each system.

ExpertPower 12V 50Ah Lithium LiFePO4 Deep Cycle

Here is an example of a highly rated dual zero capable battery

ExpertPower 12V 50Ah Lithium LiFePO4 Deep Cycle Rechargeable Battery | 2500-7000 Life Cycles & 10-Year lifetime | Built-in BMS | Perfect for RV, Solar, Marine, Overland, Off-Grid Applications

Click the image to see more details on Amazon.

The Goal Zero system should at least be considered if you’re interested in a more eco-friendly option because you care about reducing your carbon footprint.

Goal Zero Yeti 500X Portable Power Station

Here this example from Amazon – Ideal for a quick start;

Goal Zero Yeti 500X Portable Power Station, 505Wh Portable Lithium Battery Emergency Power Station, Outdoor Solar Generator, 120V AC Pure Sine Wave Inverter, 12V Car Port, 6mm, USB C PD, USB A Port…

Click the image to see more details on Amazon.

You can buy panels in different sizes to accommodate your needs, and the system is easy to use even for beginners.

Both systems charge devices in several different ways, and both systems are very well made and long-lasting.

Should You Buy a goal zero or dual battery?

The bottom line is that both of these systems have pros and cons, so you first need to determine which of their features is most important to you. A dual battery system is typically used for larger solar panel installations. With a focus on keeping the system operational is one battery does go down.

If you are looking for a battery for your RV camper or for any other portable use, Goal Zero is the best option for you.

The Goal Zero system also tends to have a lot of ports for your accessories, whereas the dual-battery system usually does not.

Goal Zero or dual battery system, it just depends on the size of your system and if a backup is required or if portability is what you need.

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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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