Modern solar calculators use solar cell panels and batteries for energy storage. They work similarly to basic calculators but eliminate the need for frequent battery changes. If you’re wondering how to charge a solar powered calculator, we have got you covered. In this blog, we will also discuss ways to charge them without sunlight and the factors that affect their performance.
How to Charge a Solar Powered Calculator
To charge a solar powered calculator you put the panel directly into sunlight. Give enough time for the solar panel to convert sunlight into electrical power and the calculator will charge on its own.
Here are the steps taken in charging a solar calculator.
1. Find Solar Panel
It should have a tiny solar panel either at its front or back end, so look out for it. The material, which is usually a dark color or black turns solar energy into electricity.
2. Put the Calculator in Sunlight
Expose the calculator’s solar panel to direct sun rays. Make sure no object acts as an obstacle and block light. Such an obstacle can be a shadow or anything else. This will weaken the effect of charging.
3. Allow Time for Charging
You can leave the calculator exposed to sunlight long enough for complete charging. However, a few hours spent under direct sunlight will suffice for most solar calculators.
4. Check the Battery Indicator
Some solar calculators have battery indicators that show a graph of battery levels. Upon completion of charging, the indicator should show either a full battery icon or a signal.
5. Store the Calculator
However, when the cell phone gets charged fully you may choose to store or use it as often as necessary. The batteries of solar calculators will keep charging as long as sunlight lasts.
The calculator’s solar panels should be clear of dirt and broken places to allow maximum sun absorption if you face any challenges in charging. This will ensure efficient charging in the long run. Now, let’s see how to charge a solar calculator without the sun.
Also See: 5 Best Solar Powered Calculators
How to Charge a Solar Calculator Without the Sun

Solar powered calculators can be charged artificially with ordinary light bulbs and/or LED lamps. It must be placed near light sources so that they are able to charge the battery, but not so close to avoid any damage.
While charging a solar calculator without the sun, you must consider the following points:
- Ensure the battery gets enough energy by maintaining consistency in the quality of light from a source that remains undisturbed for at least one hour.
- Note that this power rating depends on the brightness intensity of the source, the calculator’s solar panel size, as well as exposure time length.
- It’s advisable initially to have a very short charge before building up the exposure period as an extended charge can harm the battery.
- You could opt for an extra charger cable if a power source cannot illuminate sufficiently and charge your calculator.
Moreover, flashlights are not considered one of the ways to charge a solar calculator without the sun since they generate minimal light energy. Flashlights have to use batteries to generate light, which is why they are not a viable option for charging calculators.
How Long Does a Solar Calculator Need to Charge?
A calculator needs up to 20 hours in direct light for it to get full charge. However, in some cases, within 3 to 5 hours, it will be charged, and you can even charge it indoors with incandescent bulbs. But without natural lights, they may take a long time to recharge.
However, several factors affect the solar calculator’s charging time, which includes the battery amperage-hour value, the surface area of the solar panel, the charging circuit efficiency, and the battery discharge efficiency among others.
Cross-Reference: How Much Energy Does A Solar Powered Calculator Need?
Do Solar Powered Calculators Last Forever?
No, a solar calculator does not last forever. The batteries in a calculator, often last up to 5 – 10 years. This means they live much longer than some calculators. Battery life can be calculated as the ratio of the total capacity and power of the circuit in the calculator. A low self-discharge rate and the battery’s power retention make the battery last for a long time.
In addition, you must consider the storage time of the battery. The majority of contemporary calculators contain a solar panel that can restore energy to the calculator when it gets exposed to light. Therefore, when the battery does not work, you can still use it by charging the solar powered calculator under the sun.
Also See: How Long Do Casio Solar Watch Batteries Last?
Factors Affecting the Life of Solar Powered Calculators
A few factors that affect the life of calculators are:
- Daily usage: A solar-powered calculator’s life depends on its utilization frequency. The higher frequency of use means the shorter life span of a projectile.
- Maintenance: Taking care of your calculator by recharging it on time and cleaning regularly may extend its lifetime.
Also, take a look at the Solar Panel Charging Time Calculator.
Guidelines for Maintaining a Solar-Powered Calculator
You can follow these few basic tips and maintain your solar calculators:
1. Recharge the battery often: The battery needs to get a full charge and should be completely exposed to light. But, direct sunlight exposure for a long time causes solar cell damage.
2. Clean the solar cells: Dirty or grubby solar cells should be cleaned regularly to allow efficient absorption. Apply some amount of soft lint-free cloth or paper towel on them to remove dust and debris particles away.
Following these few tips, users can make it possible for the calculator to last longer and perform at its optimum level.
Today, we learned that charging a solar-powered calculator is easy. You just need to place it in direct sunlight to charge. However, the duration of charging will depend upon the capacity of its battery and the intensity of sunlight with which it is exposed.
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