Using a 200-watt solar panel that produces 1 amp of power, a 12-volt battery may be fully charged in 5 to 8 hours. However, things become a little more complicated. Several variables affect the charging time. Solar panel quality, charge controller efficiency, battery condition, the quantity of sunlight absorption, and more all have a role in how well a system performs.
However, assuming your battery’s amp hour rating matches the amps generated by solar panels, the charging time would most likely fall between around 5 and 8.
It’s also a good idea to make sure your solar panel is facing straight towards the sun, with no obstructions. On overcast days, charging will be slower; charging will be faster on sunny days.
On average, a 300-watt solar panel could charge a 12-volt battery for 5 hours. However, the quantity of sunshine you receive and the amperage of your battery will affect the amount of time your battery takes to charge.
Four factors influence the charging time of your battery:
- Batteries have a certain amount of amperage
- How much sunshine you are exposed to
- The amount of power generated by the solar cell.
- The amount of battery life remaining.
Here, the amperage is the most crucial quantity. The battery’s capacity is the amount of energy it can hold. There is more accumulated power in a battery with greater amperage and a longer charge time.
Generally speaking, a battery with a capacity of 100 AH will charge half the time as one with a capacity of 200 AH.
The average quantity of sunshine each day when the solar panel runs at maximum capacity would be around the 5-hour level, regardless of the season.
For off-grid or battery-backed solar panels, utilize deep-cycle batteries for your battery backup. The only thing that resembles your automobile battery is in the form of deep-cycle batteries. In contrast to vehicle batteries, which only deliver power for a brief period, rechargeable lithium batteries continually drain their charge.
You may utilize up to 80 percent of the capacity of deep cycle batteries without risking serious harm. Only 80 amp-hours should always be used from a battery that has a 100 amp-hour capacity. If you want to extend the shelf life of your product, manufacturers recommend not dropping below 45 percent. This is why deep-cycle batteries are ideal for solar systems since they have these properties.
Process of charging a battery
To maximize the amount of solar power your panels collect, it is essential to have batteries with a large capacity. In addition to your solar panels, you’ll also need an inverter and a solar charge controller to get your solar system up and running.
Batteries allow you to store any extra energy generated by your solar panel installation. The power you generate will be returned to the utility system whenever your batteries are complete.
Charge controllers may interconnect your solar panel to your battery bank. To avoid overcharging, it regulates the quantity of energy in your battery. When batteries get low, charge controllers shut off the system to protect them.
How to Calculate the Charging Time of a Deep Cycle Battery?
The amount of time it takes to charge a battery depends mainly on the battery’s capacity and the power rating of something like the energy supplies. The amperage, the voltage, and indeed the wattage are all things you need to know.
In electrical terms, what is “wattage?”
Under ideal circumstances, including such sunlight and warm temperatures, a solar panel’s wattage represents the solar panel’s power generation. More information on the daily output of a 200-watt solar panel may be found here.
A 200-watt solar panel must theoretically provide 200 watts of electricity. It’s not as straightforward as that, as we’ll see in the next section.
What Is Voltage, Anyway?
In a nutshell, voltage is the amount of force exerted on the current.
Your battery’s voltage tells you how much power it has. For voltage, volts are the unit (V).
What Is an Amp-Hour?
You need to understand amp-hours. Amp-hour describes the amount of amperage a battery can provide in a certain time period.
The Ah number is used to describe the amp-hour capacity of deep cycle batteries. Knowing the AH rating of your 12V battery, you can determine the amp rating of your 200-watt solar panels. It’s easy to figure out how long it will take to charge a 12V battery if you know your amp rating.
To learn more about amps, check out the amperage of a 200-watt solar panel.
The formula for calculating the amps of current generated by your solar panels is as follows:
Power (Watts) / Voltage (Ah) = Amps (Ah) (V)
The amp rating is calculated by dividing the power by the voltage.
In this example, if your deep cycle battery has a capacity rating of 100 amp hours, and your charger does have a power output of 10 amps per hour, it would take 10 hours to charge the battery, for example, completely.
Which Solar Panel Produces the Most Power?
Only roughly 70 to 80 percent of the rated power of a solar panel rated at 200 watts/12V may be generated daily.
Put another way, the rated power produced at the testing facilities is based on the lighting and temperature conditions.
Finding this at the installation locations is not out of the question. Just be aware that the data will be imprecise at best. Several variables may affect the quantity of power generated, and we will discuss that throughout this article.
My 12V battery requires a solar panel that can provide enough power to charge it.
Although you may charge a 12V battery with any solar panel as long as it has a 12V output, linking your solar panels immediately to your battery is not an option. Starting with the charge controller is essential, which controls the flow of energy from the power source, in this case, your solar panels, to your battery. They prevent the battery from overcharging, which may cause severe harm.
The DC electricity generated by your solar panels will need to be converted into AC power by a power inverter, which most utilities, including electronic gadgets, need.
It might be a little frightening when you just start looking at solar and battery choices. There’s a lot to think about here, from figuring out how to convert amp hours from volts to sealed lead acid to flooded lead acid. To choose the best battery bank for your household’s requirements, perform some basic arithmetic, figure out how much energy you consume, and familiarise yourself with the various battery possibilities.
With the help of this article, you will now understand how you can fast charge your 200watt solar panel with a 12v battery. That will make installing the solar panel system at your place much easier and more effective.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.