20 Watt Solar Panels (All You Need To Know)

20-watt solar panels are one of the smallest solar panel sizes and at the lowest price-point. They are useful for many applications in the home and on the go.

Here are some of the key aspects of 20-watt solar panels this article covers;

  • Sizes
  • Power
  • Longevity
  • Cost

If you’ve got a 20-watt solar panel or are interested in what they can do, this article has the answers for you.

20 Watt Solar Panel

How Big is a 20W Solar Panel?

Usually, these panels are monocrystalline panels that can provide up to 20W of power. Their size dimensions usually lie between the following ranges:

  • Height: 350 mm to 490 mm
  • Width: 350 mm to 435 mm
  • Depth: 17 mm to 25 mm
  • Length: 450 mm to 490 mm
  • Weight: 1.5 to 3.0 kg

A 20W solar panel is generally a small-sized panel that is suitable for a number of applications in the;

  • home
  • automotive
  • caravan
  • RV
  • marine

This is where tiny batteries must be trickled charged, such as;

  • garden
  • lighting
  • home surveillance systems
  • home irrigation systems
  • electric fences
  • electric gates
  • security cameras, and more.

What is The Power Output of a 20-watt Solar Panel?

The amount of power that a solar panel can produce depends on the total hours of sunlight you are receiving daily and thus the output a solar panel produces differs on this basis.

There is a very simple formula that allows one to calculate the total power output for their solar panel i.e. (Daylight Hours x Efficiency of Solar Panel).

So for say you receive 5 to 7 hours of sunlight daily for your 20-watt solar panel then the total power (KWh) generation for this solar panel would be between 100 to 140 KWh daily.

Thus, the amount of power a solar panel generates will keep on varying depending on the daily sunlight hours and how much your panel is receiving

What is The Amount of Current (Amps) that a 20-watt Solar Panel Produces?

Under optimum conditions, a 20W solar panel can create 1.34 amps per hour.

For example, under perfect conditions, the panel will produce 20 Watts for 7 hours per day, 7 days per week, for a total of 980 Watts.

To reduce total charging time, you can connect several panels together. You may double your production and cut your costs by installing a second panel with the same output for the duration of the charge

What Can a 20-watt Solar Panel Run?

A 20 Watt Solar Panel is designed to be used with lower-powered electrical items, which when used will allow the panel to be charged the following day.

Here are some common items that people use their 20-watt solar panel to run;

  • Cell phones
  • Cameras – digital and security
  • Lights
  • Electric toothbrushes
  • Mini pumps

This type of solar panel is ideal for your personal gadget when you’re camping, RVing, or on the move.

A 20-watt solar panel is great around the garden when you don’t have a power supply around your property and want to hook up some lights or a security system.

Does a 20-watt Solar Panel Require a Charge Controller?

The simplest solution to determine whether or not your panel requires a charge controller is to divide the battery’s current capacity with the panel’s highest power generation rating.

A controller has not required in the case that the factor is more than two hundred. A controller is required if the number is fewer than 200.

For example, if one has a battery with the capacity of a hundred amp/hour and a panel of 10W, the product of these capacities i.e hundred multiplied by six (600mA) will give you 166.6.

You’ll need a charge controller because this is less than 200. In the preceding example, if you have a five-watt panel, split 100 by.3 (300mA) to get 333.3.

You won’t need a charge controller because this is bigger than 200. However, a blocking diode is still required to keep the bat at bay.

In the case of a 20-watt solar panel, most of them come with a charge controller which maintains the battery health and lifespan of 12V batteries.

What is the Duration in Which a 12V Battery is Charged by a 20W Solar Panel?

See also  Solar Panels Under 1000$ (What You Need and Why)

Depending on the Sunlight hours, a solar panel 12v battery charger producing one amp of power requires about five to eight hours or more in most situations to charge.

To get the most out of a solar panel, keep it aimed squarely at the sun to maximize the amount of electricity it can generate.

What is the Average Cost of a 20W Solar Panel?

On average, a monocrystalline solar panel costs between fifty and one hundred dollars, and a small portable 20-watt solar panel will cost anywhere between thirty to one hundred dollars to charge phones and other mobile devices.

This is a very cost-effective alternative to larger systems especially when you want to charge your appliances on the go making use of the sun’s energy.

Solar blankets range in price from fifty to as much as five hundred dollars, depending on size, model, and gimmicks.

When buying a solar panel, one needs to be careful to account for the price of add-ons – most systems come with the full kit which is ready to go, straight from the box.

Make sure that your kit has the connections, battery, inverters/charge controller, and ports that you will need to charge your gear.

How Long Would a 20-watt Solar Kit Last?

For a basic kit, after roughly two or three years, you may notice a decrease in your system’s power output. Your portable solar kit will be of little use after eight or more years.

For commercial solar panels, they can last up to 20 years or more. So when you are buying your 20-watt solar panel kit, it’s worth paying the extra few bucks for a well-known brand that is reputable, so you get an extra few years from it.

If you do buy the part separately, make sure that you have the correct gauge cables and fuses to prevent and unnecessary overload to the system – this can quickly kill your new panel.

In most cases it’s best to buy the full package together so that you know that the kit has been designed to work as one unit.

This well-made waterproof 20-watt solar panel is an all-in-one unit that just needs a battery to be charged.

SUNER POWER Waterproof 12V Solar Battery Charger & Maintainer Pro - Built-in Intelligent MPPT Charge Controller - 20W Solar Panel Trickle Charging Kit for Car, Marine, Motorcycle, RV, etc
811 Reviews
SUNER POWER Waterproof 12V Solar Battery Charger & Maintainer Pro - Built-in Intelligent MPPT Charge Controller - 20W Solar Panel Trickle Charging Kit for Car, Marine, Motorcycle, RV, etc
  • [Charge Anywhere] Transfer sunshine into electricity, charge and maintain your 12 volt battery in all seasons. The most advanced MPPT(Maximum Power Point Tracking) chip intelligently manages to charge and fully protect the battery. US PATENT PENDING!
  • [Intelligent Charge & Maintain] Built-in intelligent MPPT charge controller, generates at least 10%-20% more power than traditional controller. Smart 3-stages charging algorithm is improved to better charge and maintain battery in all seasons.
  • [Full Protections] Prevent the battery from over-charge, over-voltage, discharge, and short circuit, reversed polarity protection, waterproof and spark-proof, the battery is fully protected.

Can 20-watt Solar Panels Power Gate Openers?

In the absence of an alternating current power supply, the 20W solar panel can charge a 12V gate operator battery.

An efficient 20W solar panel kit for a 12V gate opener battery normally includes tubular steel support, mounting clamps, wire connectors, and eight feet of low voltage cable for the most resourceful power supply.

However, a 20W solar panel is not usually convenient for a gate opener battery as more than one panel is required for efficient results in many cases.

The required wattage is determined by the gate opener’s own power requirements, other access restrictions and gadgets that drain the battery, and the amount of sunlight exposure.

When using a 20W solar panel, it is advised that you acquire an optional second battery for backup cycles on overcast days if you have a single gate.

Can 20-watt Solar Panels Power RV Batteries?

A 20W solar panel is ideal for charging RV batteries on road. An efficient charging solution uses a 20-watt solar panel and solar controller to give your RV batteries a boost.

Power output is regulated and monitored by the controller, which prevents dangerous overcharging.

If you’re an environmentally aware RV owner, then a 20W solar panel charging system offers clean, renewable energy as well as a means to trickle charge your batteries while you are traveling.

A typical 20W solar kit for RV batteries should include all the basics that the user requires for the sun to charge their RV batteries such as;

  • an efficient mono crystalline solar panel that is weather and impact resistant
  • a ten amp or more solar controller for efficient output
  • high grade cables and the necessary installation hardware.
See also  Can You Turn Off A Solar Panel? (Do This)

This type of system gathers solar energy and converts it to direct current electricity, which is then used to charge your RV batteries using a solar controller.

Such systems are very efficient automated multistage smart systems that also help in extending the battery life.

What are Some of the Best 20-watt Solar Panels Available?

Some of the Best 20-watt solar panels available on the market are the following:

  • 20-watt solar panel kit by TopSolar.
  • 20-watt poly crystalline 12V solar panel kit by Suner Power.
  • 20-watt 12V solar trickle charger by TopSolar.
  • 20-watt 12V poly solar panel by Rich Solar.
  • 20-watt mono crystalline 12V solar panel by HQST.
  • 20-watt epoxy solar panel by Eco Worthy.

All these solar panels are lightweight, portable, made of anti-corrosion material, are cost-effective, durable, provide high efficiency, are easy to install, water-resistant, and perform better than the user’s expectations.

Most of them are manufactured using a strong tempered glass and aluminum frame, monocrystalline cells that have high efficacy and provide in-built protection against overcharging.

Hopefully, that’s answered all of your questions about 20-watt solar panels and you’ll know what they’re good for and what they can and can’t do.


General Solar Panel FAQ

Sol Voltaics is an affiliate and an Amazon Associate, we earn from qualifying purchases - at no extra cost to you.


Sol Voltaics Logo Icon green white

Sol Voltaics
1043 Garland Ave
Unit C #737
San Jose
CA 95126-3159

Available for Amazon Prime