What Size of Solar Panel Do I need to Charge a 12V Battery

According to the SEIA insights report, in 2022, Americans installed enough solar panels to supply power to 22 million homes. This sure is welcome news knowing that more and more people are embracing the power of nature. If you’re one of the many who are looking to use solar energy, you may feel a little intimidated and have a long list of questions on hand; don’t fret we’re here to help!  

In this article, we’ll try to answer frequent questions we receive about solar battery units, such as, “Can I use my solar panel without battery storage?” or “What solar panel do I need to charge a 12v battery?” 

Can I use my solar panel without battery storage?

To quickly answer the question - yes, you can use solar panels for your home without battery storage. However, solar batteries are essential for certain scenarios: 

• If you live in an area where the power grid is unreliable, you will need a solar battery unit as a backup to supply electricity to your appliances when the utility power is down. 
  

• If you’re planning to live off-grid or buy a tiny house kit, having battery storage for your solar panels will enable you to be fully independent of traditional utility providers.    
  

• You have to consider that the sun isn’t always out 24/7. There are times when you’ll have higher energy needs (like early morning or evening), and production from your solar panels may not be enough so you can go about your usual activities. Sure, you can alternately draw power from the local grid, but this is a step back from energy independence.   

So, if you’re looking to buy a solar panel kit, solar batteries are great to have so that your system meets your energy demands. 

It helps to remember that when choosing which battery to purchase, you want to check that it matches your solar system. You want to ensure that your solar panels will effectively charge the battery and that the battery has enough power to supply what you require. 

Everything You Should Know About Solar Batteries

As mentioned, it’s essential that you correctly match the components for your solar system, including your solar panels and battery storage, so you can use it optimally. Having a deeper understanding of solar batteries will help you do this.

What are deep-cycle batteries?

Solar batteries are also called deep-cycle batteries. If you do an image search on this, you may notice that they look the same as the batteries used in vehicles, but they are actually different. Deep cycle batteries have the ability to handle frequent and long deep charge and discharge cycles (they can be discharged for up to 70%). These are the same reasons why deep cycle batteries are popular for off-grid solar systems, plus they aren’t easily damaged. In fact, solar battery units can last anywhere from 5 to 15 years.

How do solar panels charge the battery?

To understand how a solar battery unit is charged, you have to remember the four major components of a typical solar power system, which are: 1. solar panel/s, 2. charge controller, 3. battery, and 4. inverter. 

Here’s how it works…

As sunlight hits the solar panels, the panels will convert the sunlight into DC (direct current) electricity to charge the battery. This electricity is supplied to the solar battery through a charge controller or also known as a solar regulator. 

The charge controller is responsible for regulating the current from the solar panels so that the battery won’t overcharge (they can also shut down a system if the energy in the battery is almost depleted). The battery will then store the energy as DC electricity. 

To supply power from the battery storage to your appliances, the DC electricity exits the battery into the inverter. The inverter then converts the DC electricity into AC (alternating current) electricity, which is the type commonly used in the majority of household devices.  

How are solar batteries rated?

Solar batteries are usually rated in Ampere(Amp) Hours (Ah) or watt-hours (Wh). It is important to take note of this as this rating determines how long the batteries can supply power to your devices before it needs to be recharged. Naturally, the higher the battery’s capacity is, the more energy it can store. 

For example, a solar power kit that has a 4800Wh battery can run a 100W fridge for 48 hours before you need to recharge it. While a battery rated at 60Ah can provide 60 amps of power for an hour or 6 amps for 10 hours. 

What size solar panel do I need to charge a 12v battery?

Now you may be wondering, whether you have the right size solar panel/s to charge the battery storage that you’re planning to purchase. 

Here’s a sample calculation to help you determine the answer:

• Say you’re looking to buy a 12v 100Ah deep cycle battery.  If you multiply the voltage and amp hours, you’ll get 1200Wh.

12v x 100Ah= 1200Wh

• Divide the answer above (1200Wh) by the estimated amount of sunlight (in hours) that is available each day, for example, 6 hours, and you’ll get 200 watts.

720Wh/6 hours = 200W

• The answer tells you that you need to have solar panels that have 200-watt recharging power. 

Important note: More often than not, solar panels won’t produce their optimal level of energy (due to sunlight, charging cycles, etc.) so you have to use solar panels that can produce slightly above the number that you will get – in our example, above 200W. 

Best Solar Power Solutions

If you want to make your life much easier and have an efficient solar power system for your home, we highly recommend you check out the range of products that we offer here at Nature’s Generator.

You can choose from portable solar generators (Nature’s Generator 1800W 720Wh or Gold System that comes with a 100W Solar Panel); our Elite Line (3600W 120Wh), which is ideal for off-grid homes; and Powerhouse Line (7200W 480Wh), which is our whole-home solar generators.  

All our generators have an LCD Display that shows the battery level, input information, and more. Only minimal maintenance is required for our generators (e.g. recharge the battery once every four months for on-use).

The built-in batteries that we use for Nature’s Generator are sealed lead acid, known for their efficiency, safety, and low cost, however, as of Feb 2023, we just introduced the Eco-Intelligent Li battery management system (BMS) to our Powerhouse line of whole-home generators.

The Eco-Intelligent Li uses a Lithium Iron Phosphate (LiFePO4) battery technology at its core which is known for its safety and long-life span (up to ten years!). With this new product we now offer a straight SLA Powerhouse system, a straight LiFePO4 Powerhouse system, or a hybrid Powerhouse system that utilizes the strengths of both the LiFePO4 and SLA technologies.

The Eco-Intelligent Li was designed to save user money when buying or upgrading their whole-home solar energy systems. It allows for SLA and LiFePO4 technologies to be used in tandem and it also solves the problem of old and new battery compatibility.

The best thing about all Nature’s Generator systems is that they’re customizable. This means you have the power to add more power pods, solar panels, wind turbines, etc., to expand your solar system to fit your needs.

Nature’s Generator has some of the most affordable solar-powered energy solutions available. Plus, we want to remind homeowners that the U.S. federal solar tax credit has recently been raised to 30% which can greatly reduce the cost of installing solar-powered renewable energy systems on U.S. home. Please see this link for more information on this money-saving incentive see: Guide To The Federal Solar Tax Credit

Need help?

If you’re interested in our solar generators or have questions about setting up your own solar system, please don’t hesitate to reach out to us. Our team are more than happy to attend to your inquiries. 

* We want to give credit where credit is due. Professional writer, Ishna Sablaya, contributed research and content to this blog titled: What solar panel do I need to charge a 12v battery Thank you, Ishna, for your contributions!