As we continue to move forward digitally, we find ourselves with more and more portable electronics. Some items like a phone or a laptop seem necessary these days, and oftentimes, when you are traveling or even just moving about day-to-day, we need a way to charge it all. Solar power banks and solar chargers have become increasingly popular with business professionals and outdoor adventurers alike. So, it begs the question…
Are solar power banks worth it? In short, solar power banks and portable solar chargers offer convenience for the consumer. While they are energy-efficient, they may not always be a money-saving option. So, their worth will largely depend on their application and consumer preference.
Solar power as a whole has been growing in popularity, and the applications of solar power systems seem somewhat endless. Between convenient portable and fully off-grid household systems, there are a number of considerations to take into account when deciding if a solar power bank is an appropriate purchase for you.
Are Solar Power Banks Worth It?
Deciding if a solar power bank is worth it for you with will depend on a few relatively minor things. You will need to understand the energy efficiency, overall cost, and lifespan of the battery. Then, you should move forward to consider when and why you will be using a power bank.
The efficiency of your solar power bank will depend on the overall quality of the device you purchase. The two primary factors that will influence the efficiency of your solar power bank are the battery capacity and the correct solar panel specs. These will also help you to determine which power system fits your needs.
There will be mentions of larger solar power banks throughout this article; however, the focus will be on portable systems. If you are looking to invest in a system large enough to power a house or to go off-grid, much of the information here is applicable, just not specific to that large of a system.
Cost of an Energy Bank
As with most electronic items on the market, it seems as if the more money you spend upfront, the longer the item will last. Now, this isn’t always the case, but when it comes to investing in a solar power bank, you need to look for overall product quality.
The larger the battery capacity and the more optimized solar panel output, the more expensive the system will be. Beyond the battery capacity, the brand name and solar panel technology will factor into the cost as well.
Within the range of 10000-20000mAh for bank battery capacity, your price will be between $20-40 USD. If you are looking for capacity larger than 20000mAh, then you will be looking at a higher cost altogether. As far as compact travel solar power banks go, you should be able to get a good quality product for $60 USD or less.
Now, if you are looking for a larger solar “generator” type bank or portable power station, then you will likely be spending between $200-3000 USD. Certain brands, like GoalZero, carry power station products that are designed to run with the power of a gasoline style generator but are charged by solar instead.
All in all, the cost of your solar power bank will be up to you. If you are just looking for a simple, convenient travel option, you will not be spending over $60 USD. However, if you are looking for a back-up power source or something to bring on long car camping trips, then a larger portable power station may be a better investment.
What Can I Charge With A Solar Power Bank?
Since the primary purpose of solar power is having a power source anywhere that you happen to be, the battery has to be small enough to easily transport. With that in mind, the smaller the battery, the less energy storage it will have.
All of the portable solar system models are a little bit different in size and power capacity, but for the most part, a portable solar power bank will be able to charge
- GPS Systems
- Portable Radio and/or Speaker
- Other Battery Packs
Some of the larger solar “generator” systems will have the capability to run small appliances, and can also be used as a back-up for household items. What you can charge off of your power bank will be determined by how much energy it can store at any given time.
How Much Energy Will Be Saved?
Unless you plan on installing a solar energy system for your entire house, then you will not be saving an exponential amount of energy by using a portable solar power bank. While all electrical devices use up some amount of energy, smaller devices like phones and tablets use less than powering all of the energy eating appliances in our homes.
Portable solar power systems and storage were initially designed for emergency purposes and for backcountry or off-grid applications. These systems were not designed to power large power grids or even to be used that often in general.
Average Solar Bank Lifespan
Now, we are not talking about how long the charge lasts here. We are talking about how long the battery itself holds up over time. Once again there are a lot of variables to consider when answering this question, and how long your solar bank lasts will largely be determined by how often you use it, how well you care for it, the type of battery it is, and the initial quality of the equipment.
It is also important to note that portable power systems will more than likely last longer than solar batteries used to power a home. In a solar system designed to power the average household in the United States, you will have to replace the battery storage system within 5-15 years. This is somewhat troubling due to the fact that the photovoltaic system (PV system) usually lasts at least 30 years.
If you have to replace a power bank that is being used daily, then once could assume that it would take a number of years beyond that estimated amount to require a portable power bank replacement. If you do use your solar power bank every day, then you will be looking at replacing it within 5-15 years’ time.
Some companies will have specifics in regards to replacing batteries in the solar system. Always follow closely to the manufacturer’s guidelines in regards to battery care and lifespan.
How Solar Banks Work
A power bank of any kind can be defined as a portable storage device that can supply power from its built-in USB port. Now, a solar power bank isn’t much different than that, the primary differentiation that must be made is a solar storage unit produces its energy from the sunlight it collects.
Most solar power banks are designed to be a portable source of energy. While there are larger generator style power storage solutions powered by the sun, the most commonly used ones are small and compact renewable energy sources.
They store the energy from the sun using small solar panels then convert their solar power into stored energy in the battery pack. This battery can then be used to charge other devices such as a mobile phone or tablet. Usually, the connection point will be via a USB cable, but on larger generator style power banks, it will include multiple outlet options.
How long your solar power bank takes to charge and how long it lasts while it is charging one of your devices will vary by model depending on the battery capacity and method used to charge the power bank. One general observation that can be made is the larger the battery capacity, the longer it will take to reach a full charge.
That being said, manufacturers have come up with a simple equation to allow for estimated ranges of charge time:
Time to Charge = (Battery Capacity) / (Solar Panel Power)
When you are looking to purchase a solar power bank, the manufacturer should have already done this leg work for you. Within the packaging or on the company website, all of their solar power packages should estimate the time it takes to charge via solar panel and power outlet.
So depending on the solar panel used to charge a 20000mAh power bank, manufacturers generally put out the required time range of 60-70 hours of charge time vs. 5-6 hours charging on a power outlet. Now, we also have to remember that the intensity of the charge will be determined by climate and weather conditions. So, if it isn’t a sunny day, you will be hard-pressed to get much of a charge, if any at all.
Since predicting that actual amount of time it will take to charge via a solar panel is so subjective if you have a larger solar power bank that you will rely on for a number of days or for a trip you’re taking, it is recommended that you charge the power bank via power outlet before you leave. This will ensure that your power bank has a full charge from the start, and then you can leave it plugged into your solar power source when you are off-grid.
Holding a Charge
How long your power bank lasts off of a full charge will depend on the battery capacity and how much it is being used. If you are strictly using it to charge a smartphone once a day, then the battery will last much longer than if it is being used to charge multiple devices at the same time throughout the day.
If you plan on using the power bank for multiple days, you should be charging it via solar panel the entire time. This will allow it to continue to hold a charge throughout the entirety of your trip.
Solar Power Bank vs. Solar Charger
When searching for a solar power bank online, you will likely also come across solar chargers. While their function is somewhat similar, they serve different purposes overall. A solar charger is simply that, a charger. When you plug your device into a solar charger, it must be in direct sunlight in order to charge the device’s battery.
A solar power bank, on the other hand, is able to store the energy collected in its personal battery. This allows you to charge the power bank in the sun and have a fully charged power source no matter the time of day.
Most solar power banks do not strictly accept solar power either. You are usually able to charge them with an alternative form of energy. The solar charging system that connects to the solar power bank is usually a convenience or emergency option.
Choosing the Right Power Bank for your Device
There are a number of factors that need to be considered when deciding which purchase option to choose from. First, you must determine what you will be using it to charge and how you plan on charging the power bank as well.
Tips for choosing the right solar power bank for your needs:
- Battery Capacity
- Solar Panel Specs
- Charging Ports
- Battery Type
- Additional Features
This was discussed very briefly when we talked about charging the power bank and holding a charge. However, in order to determine what battery capacity is right for your needs, you will need to know what you will be using the power bank for.
When discussing the battery capacity in the context of a solar power bank, we are talking about the amount of energy that can be stored. When referring to the battery capacity, the energy stored in the bank is usually referred to in mAh (Ampere-Hour) or Wh (Watt-Hour) units.
One problem with measuring the battery capacity in mAh is that this unit of measurement is designed to tell us how much power the battery can put out at a given time. This is an issue because we are usually in search of the amount of power the device we are charging is draining. Overall, the higher the mAh number on the power bank, the more you will be able to charge on a full battery.
The table below gives a brief overview of mAh battery capacity and charging capabilities.
|mAh||What It Can Charge|
|< 3000 mAh||One Smartphone|
|3000 – 10,000 mAh||Phones and Tablets|
|> 10,000 mAh||Phone, Tablet, Laptop, and other small electronics|
As you can see from the table above, battery capacity lower than 3000 mAh will only be enough to charge your phone one time, and sometimes it may not even charge your phone completely. Knowing what you want to use your power bank will help you determine which one to get and also if it will be a worthwhile investment at all.
Solar Panel Specs
While virtually all of the solar power bank systems can be charged with a standard power outlet, the main draw is that you do not have to depend on the power grid completely. You can store power using the sun!
When determining the quality of your solar panels, you will want to examine both the panel cells along with the panel size. It should seem like the size of the panel would be the only concern, as a larger panel should mean it can collect more sun, but that’s not always the case.
Look at the specs of all the solar panels you are considering. Find out what the power output is as well as the general efficiency in collecting and converting solar energy. As with the power bank, sometimes you will need to pay just a little bit more in order to achieve the highest efficiency.
It is also important to consider how large of a power bank you are charging via solar panels. If it is simply a source of power for your phone on weekend trips, your solar panels will be small and compact. Whereas panels that are intended to power a battery that can run a blender or a small fridge will need a larger panel to collect more sunlight.
Once you know what you want to use your solar power bank for, you will need to consider how portable it is. If you want it strictly for backpacking trips where you need to charge your GPS, then you will be looking for something lightweight and panels you can strap to your pack while you’re hiking.
If you’re looking for a car camping power source or even a power source for a campervan, then you will be looking at something that you can move around, but aren’t expected to carry. Many of the higher capacity power banks will be the size of or just slightly larger than a car battery.
It is also important to remember that we are talking about the entire solar system here, not just the battery. Some solar panels are foldable, or some of the smaller banks have the panels built onto the battery. As mentioned before, this will be up to the consumer’s needs, but keep in mind what you will be doing and if that power bank system as a whole is conducive to your needs.
As with the battery capacity and portability, how many charging ports you need will be up to you. If you want to be able to charge multiple phones or tablets at a time, look for power banks that have multiple USB portals.
Some larger power banks will allow for a variety of plug-in options ranging from USB, standard outlet prongs, or even an auxiliary option. These banks are more suitable for people looking for back-up at home for emergencies or families looking for an off-grid car camping solution.
The majority of the solar power bank batteries on the market today are lithium-ion polymer. There are variations, such as a lead-acid or saltwater battery. Major factors to consider when you are deciding on the battery type of your solar power system is the depth of discharge and the overall lifespan of the battery itself.
The depth of discharge is referring to the amount of the battery’s full storage capacity that can be utilized or discharged. It is an alternative method used to indicate the battery’s state of charge.
Lead-acid batteries are a more traditional off-grid solar solution. The main draw that they hold is that they will generally have a lower depth of discharge and a shorter lifespan than other battery options. A lead-acid battery will usually only be an option when you are looking at converting your entire household energy system to solar, and it can be a good option for homeowners on a budget when going solar as they are the least expensive storage solution.
Saltwater batteries are most often a homemade DIY solar solution. It is considered a newcomer in the solar energy storage industry, only because they have just started to hit the market. Since they rely strictly on saltwater electrolytes, there are no heavy metals, which makes it a more eco-friendly option. The lack of heavy metals makes it easy to recycle, unlike lead-acid and lithium-ion. The major downfall is that since they’re a newer technology, there is not as much data available on their effectiveness and longevity.
Lithium-Ion Polymer batteries will be the most common battery you will come across when researching portable solar power bank systems. If it isn’t a lithium polymer battery, then it will be some sort of lithium-ion chemical composition. A lithium-ion polymer battery will have a longer lifespan and a higher depth of discharge in comparison with other battery types. Their effectiveness makes them a more expensive battery option, but you will be paying for quality.
Other features that are often worth considering when shopping for a solar power bank include:
- LED Light
- Aesthetic Design
- Clips, hooks, and hoops for hanging
- Foldable panel options
- Waterproof or Water REsistant
- Cables and Adaptors Included
When shopping for a new gadget, it can come down to the little things when making your decision.
Top Rated Solar Power Banks 2019
If you’ve made it this far in your research, you might as well look into a few of your options. We’ve picked out five of our favorite solar power banks on the market today. It is hard to choose just four with so many options today, but this can be a good place for you to jumpstart your digging.
The four best solar power banks ranging from small compact batteries to portable power stations:
- BEARTWO 10000mAh
- ZeroLemon 26800mAh
- FEELE 25000mAh Solar Power Bank
- GoalZero Yeti 400 Lithium Portable Power Station
This power bank is for those strictly looking for an economical option for charging their phone. With the small, compact design, it makes this a perfect option for a traveler or backpacker looking for a lightweight option to clip on and go.
Not only that, but even with its waterproof technology, you will only be paying around $25 USD for a portable solar power bank.
Specs: 10,000mAh battery capacity, 4-5 hours to charge via solar, weight of 7.4 oz
Similar to the last option, the ZeroLemon is a compact easy to travel with a power bank. It does, however, have a much larger battery capacity allowing you to charge multiple devices or one device multiple times.
Designed to be clipped to the exterior of a backpack, the ZeroLemon design has an adventure in mind. Beyond the awesome LED light built-in for convenience, the case is designed to protect the bank from shocks and damages, making it the perfect outdoor companion.
With the added battery capacity and additional features, this brings the price up a bit more, but still affordable at around $60 USD>
Specs: 26,800 mAh battery capacity, weight of 19.86 oz
Moving into larger options, this FEELE Solar Power Bank will be larger due to the foldable solar panels. This is to match the larger battery capacity and to allow for a more efficient solar collection and conversion when charging.
With the high battery capacity, it will be heavier than the earlier options but has the ability to charge most devices up to 12+ times on a full battery. Keep in mind that in order to reach a full charge, it can take up 25-30 hours using strictly solar to charge the power bank. While that may seem like a long time, this is actually one of the most efficient power banks in its solar charging abilities.
This will run around $40 USD making it a mid-range purchase option for travelers that aren’t worried about weight.
Specs: Waterproof, 25,000mAh battery capacity, 4 solar panels 5W 1A current, weight of 1.18 lbs
Moving onto the big guns, GoalZero has a lot to offer in the form of solar power systems, and their portable power stations are some of the best on the market today. With a range of sizes and abilities, you can mix and match to find the perfect combination for your power needs.
The Yeti 400 comes with a replaceable lithium battery and versatile powering options, including three USB ports, two AC outlets, and 12V output. If you’re looking for an emergency backup power for a few hours or something to bring car-camping. You will be able to charge anything from your phone, laptop, camera, or table multiple times and can run small appliances off of it as needed. This is a great option running at about $600 USD, but keep in mind that price is only for the power bank, it does not include solar panels.
Although it has a high battery capacity, it only takes about 7 hours to charge via wall charger and between 4-32 hours, depending on the capabilities of your solar panels.
Specs: 428 Wh battery capacity, weight of 16.3 lbs