Are solar-powered backpacks any good? (Buyer’s Guide + FAQ)

Yes, buying a solar-powered backpack is a very good investment, if you are a person who travels a lot. Especially this is a good power source for persons who may have to go off-grid for like campers, wildlife photographers, hikers, etc.

With a solar-powered bag, you do not have to worry about your devices running out of battery. Also, you do not have to search for power stations just to charge your mobile phone.

What is a solar-powered backpack?

Solar-powered backpack is also worked as a solar charger. Unlike solar chargers, you can charge your battery/ devices on the go without worrying about carrying the solar charger separately.

Solar-powered backpack consists of the following main components;

• Flexible solar panels
• Charge controller
• Solar battery
• DC-DC voltage converter
• Cords
• Emergency bulbs

*some solar bags do not consist of a charge controller and a solar battery.

How does a solar-powered backpack work?

Solar panels are mounted on the front of the bag. When solar panels are exposed to the sunlight, they will absorb the energy of the sun. Then the panels will convert the energy to electricity.

The output power is given as a DC voltage. This DC voltage is either supply directly to the device or stored in a battery to use whenever you want. When storing the power in the battery the process will be regulated by a charge controller.

Then before transferring the power to the device, the power will go through a DC-DC converter to decrease/step down the voltage to the device voltage.

Most solar-powered bags are designed to give out 5v, as most devices need 5v.

Advantages of using a solar-powered backpack :

• No need to carry backup batteries or power banks to charge your devices- when using solar-powered backpacks, you do not have to worry about having extra space for carrying the backup batteries and chargers.

• No need to worry about having power outlets nearby- with solar-powered backpacks you can charge your device even when you are traveling. You do not have to go to a power station or any power outlets to charge your devices. This is very useful for travelers as it is not possible to always get to a power station.

• Good for going off-grid for a long time- with solar-powered backpacks you can use your devices, without any grid connection for a long time. This is useful for travelers, hikers, and wildlife photographers.

• Protect the environment- unlike grid-powered energy solar energy does not release any harmful substances to the environment during the electricity generation process. Many countries burn fossil fuels to generate a higher percentage of their grid power supply. This will emit so many pollutants that cause global warming, acid rains, etc. So by using solar energy you can protect the environment.

• More reliable- even though you use backup batteries and power banks, you have to charge them as well to use them. But with solar-powered backpacks, you do not have to worry about charging extra devices.

Disadvantages of using a solar-powered backpack?

• Expensive than normal chargers and power banks- when compared to regular power banks, backup batteries, and chargers, solar-powered backpacks are expensive.

• Need sunlight- to work, solar-powered backpacks need sunlight. Solar panels cannot operate without sunlight. If you purchased a good quality bag they can even work under low light conditions. But the efficiency will be less.

• Design – many complain that the most solar-powered backpack’s designs are not comfortable. So when purchasing a bag you have to be careful about its design. Otherwise, it will be hard for carrying.

What you should consider when buying a solar-powered bag? – Buyer’s guide 

• Output voltage- most solar-powered backpacks are designed to give 5v as the output voltage. But you can buy solar-powered backpacks with higher output voltage than this. The value for the output voltage should be decided according to the voltage required by your device.

• Compatibility- before purchasing the product makes sure that it is compatible with your device.

• Battery capacity- battery capacity should be decided by guessing how much time you need to get power from the backpack to charge your device without sunlight. To decide this first you should find the current (A) and the time (h) each device needs separately, and then multiply the current (A) from the time (h) separately. Then you can find the capacity of the battery (Ah) by adding the final values together.

• Power of the solar panels- the power of the solar panels (Watt) means the power that the solar panels give per second at the optimal conditions. If the value is large, solar panels produce more power per second.

• Weight- usually a solar-powered backpack weighs around 4 – 5 labs. This can vary according to the size of the panels, batteries, and extra space.

• Design – The design of the solar-powered backpack should be comfortable for you. It is better if it has pads on the straps and the back as you have to carry the bag.

• Warranty- usually most quality manufacturers offer you a warranty period of about 1 – 2 years. By this warranty, they will cover any manufacturing errors. So make sure that the product has that warranty period before purchasing it.

• Manufacturer- normally products from qualified, well know manufacturers are expensive than low-quality products. Even though the price can be high it is very important to purchase quality products as less quality solar-powered backpacks have many errors and they do not work properly. Also, fewer quality products have less lifetime. 

FAQ

1. Does a solar-powered backpack need direct sunlight?

No, they don’t.

Most solar panels used for solar-powered backpacks are made from monocrystalline silicon. The efficiency of this type of solar panel is high. So they can work even if they are not under direct sunlight.

But there should be adequate sunlight to generate enough power to charge your devices.

*There are so many low-quality products available in the market. They will not be able to generate electricity if they are not under direct sunlight. So make sure to purchase the products from a qualified manufacturer.

2. Is solar-powered backpack weatherproof?

Solar-powered backpacks are designed to be weatherproof to protect their panels, internal circuits, and batteries.

But we cannot assure this, as there are so many low-quality products available on the market. Even though they are stated to be waterproof, they are not. So as a precaution make sure to use the rain cover that comes with the bag when raining.

3. Do we need to purchase a power bank and charging cables additionally?

This depends on the product you are purchasing.

Some solar-powered bags come with inbuilt batteries and cords and some are not. So when purchasing you have to check whether the bag comes with inbuilt batteries and cords or not.

4. What is the average lifetime of a solar-powered backpack?

The average lifetime of a solar-powered backpack mostly depends on the way you use it. If the bag is made from good quality materials you can use it for around 3 – 5 years or more, if you use it properly.

The average lifetime of a solar panel is about 25 years and the average lifetime of a rechargeable battery is about 3 – 5 years.

5. How long will it take to charge the inbuilt battery of the solar-powered backpack?

This time depends mainly on the capacity of your battery (Ah) and the power of solar panels (W).

Let’s clear this out by a simple calculation;

If your battery capacity is about 6 Ah and the voltage is 12 v, then you can get the total energy to fully charge the battery by multiplying the capacity by voltage.

Energy needed (Wh) = Battery capacity (Ah) * voltage (V) = 6 Ah * 12 v = 72 Wh

Then if the power of the solar panels is 20 W, you can calculate the total time the battery needs to be fully charged by dividing the energy (Wh)  by the power (W).

Time (h) = Energy (Wh)/ power (W) = 72 Wh/ 20 W = 3.6 h

*this time will vary as you cannot expect the panels to be worked at maximum efficiency at all times. One of the main factors that affect the efficiency of solar panels is light intensity. The light intensity varies all the time, so the efficiency of the panels also varies. (Read more – 12 factors that affect the efficiency of solar panels.)

Also, this time will increase if you connect a device before the battery is full.

6. Does a solar-powered backpack have enough space?

Most of the solar-powered backpacks are designed with enough room to store the other accessories.

They come with multi compartments, so you can organize your accessories properly.  You should check whether the bag you want to buy has enough space before purchasing it.

7. What are the devices we can charge with a solar-powered backpack?

Most solar-powered backpacks are designed to give 5v output voltage. This voltage is enough for your mobile phone, tablet, camera batteries, etc.

But if you want to charge a device like a laptop then you have to purchase a bag that is designed to give that voltage.

8. Can using a solar-powered backpack harm your devices?

The answer is yes and no.

Solar-powered backpacks also work as solar chargers. The main differences are unlike solar chargers, with the solar-powered bag you can charge your devices on the go and you do not need extra space to carry the device.

So same as a solar charger, when purchasing a solar-powered backpack you have to make sure that the backpack is compatible with your device and it is a quality product.

If it is not compatible with your device it can harm your device easily. Especially if the output voltage is higher or lower than the device voltage it can damage the device.

Even though you purchased a solar-powered backpack that is compatible with your device if it is a low-quality one the supply can fluctuate a lot (Usually solar-powered backpacks with inbuilt batteries give a steady supply when compared to solar-powered backpacks without batteries). These fluctuations also can harm your device.

Read more – Is using a solar charger harm your device?

To avoid any damages to your device make sure to purchase the items from qualified, well-known manufacturers.