How Quickly Do Solar Power Banks Charge a Battery?

Power banks are becoming popular because our gadgets and devices were all getting smarter and versatile tools for our everyday lives. They come in different types, shapes, and sizes, but one of the best ones you can have is a solar power bank. 

Solar power banks can be useful when you are off-grid or far from any power source. For example, if you go on a camping trip, hiking, mountain climbing, and other outdoor activities. It’s because you can use the sun’s energy to be able to charge your electronic devices. But the question is, how quickly do solar power banks charge a battery? If you haven’t used one yet, then we’re here to help answer that question. 

How Do Solar Power Banks Work?

Before we answer how quickly solar power banks charge a battery, let us know first how they work. Solar energy is used by a solar power bank to charge, and it is one of the most environmentally friendly ways to generate electricity. 

Solar power banks have small built-in solar panels that are used to charge a rechargeable battery, which usually is a lithium-ion battery. It is a photovoltaic cell panel sandwiched between a semi-conductive material that is usually made of silicon. This semi-conductive material has been altered by adding phosphorus to one end, creating a negative charge and boron to the other end. This, in turn, will create a positive charge, allowing an electrical field to be generated. 

The generated electric field causes electrons to move around within the cells. Sunlight gives off a stream of tiny particles or photons which hit the solar panel. These photons intermittently strike one of the free electrons and knock it out of the circuit. Then, it is collected by a conductive plate to produce electricity and re-charge the battery. 

Lithium-based batteries work well with solar power banks because lithium is a substance that has a high tendency to lose electrons. This means that electrons will be able to move easily from one side of the battery to the other when prompted, making them excellent for charging your devices. 

Different Types of Solar Battery Banks

As mentioned above, lithium-based batteries work well with solar power banks, and they are the most common for portable batter backs. But there are two other types of batteries that can also be used in solar power banks, which are NiMH and lead-acid batteries. 

Nickel Metal Hydride (NiMH): This type of battery is usually the rechargeable AA or AAA batteries that you can buy in packs. They are available in convenience stores and supermarkets. 

Lead-Acid Battery: This type of battery is heavy and bulky, which is not great for portability. However, it is very reliable when it comes to power output and capacity. 

How Quickly Do Solar Power Banks Charge a Battery?

Now that you know how a solar power bank works, and the type of batteries used for it, it’s time to answer the question, how quickly do they charge a battery? Basically, solar power banks use solar panels to charge a rechargeable battery, which in turn, charges your devices. Even on a cloudy day, solar power banks can charge any device, as long as there is sunlight to trigger the electrons on the solar panels. 

The amount of time solar power banks take to charge a battery depends on the wattage of the solar panel. The higher the wattage, the more solar power is harvested by the solar panel per unit time. But it also depends on your battery bank storage size. How quickly solar power banks charge a battery is a bit complex, and you need to understand some electrical terminologies, as well. This will help you understand the concept of charging solar batteries. 

Voltage (V): This is the electrical potential in the system, which is measured in volts. The higher the voltage, the more power you can get from a battery. For example, a car battery is composed of 12V, while USB ports usually have 5V. 

Amps (A): Amps is the Current or the amount of electricity. Smartphones usually draw current at 1A, while bigger devices such as air conditioning systems draw current at 15A. 

Wattage (Watts): This is the power measured in W. To get the watts, you multiply the voltage (V) by Current (Amps). 

Batteries and small gadgets like smartphones are considered as small power. They are measured in Amp-hours (Ah) or milliamp-hours (mAh). 1Ah is equal to 1,000 mAh, including the rate of charging your solar battery bank. 

Today, most gadgets, especially cellphones, charge off USB, which is fixed at 5V. To calculate the time it takes to charge your solar power bank, you can divide the power bank capacity by the power generated by the panel using the parameters from the manufacturer. There are times when the manufacturer sets a certain number of amps needed to get a good charge in a sensible amount of time. 

For example, if your smartphone is drawing a current of 1A, and it charges off USB at 5V, then your smartphone draws 5V x 1A = 5W. Then, take into consideration the current output of the solar panel. If the solar power bank claims that it is a 2W panel, then it means it will produce electricity of 400 mAh at 5V. That is 400mA per hour. Then, for instance, if the capacity of the solar power battery is 25000mAh, divide that by 400mA. You will get approximately 62.5 hours to fully charge your solar battery pack in the sun. 

If you plan to stay outdoors for a long time, then you need to buy a few pairs of the same solar power bank to keep your devices fully charged. 

We hope the information we shared helped you in figuring out how quickly solar power banks charge a battery. Determining how long a solar power bank charges will also help you in choosing the best one to take with you on your next outdoor adventure.