Friday, July 12, 2024

Rv Solar Panel Size Calculator

Solar Panel Calculator For Battery

How to Choose Solar Panel Wire Size in a DIY Camper Electrical System
  • Lead-acid, & AGM battery: 50% depth of discharge
  • lithium battery: 100% Depth of discharge
  • Charge controller type: PWM charge controller type will cause about 20% power loss
  • Inverter efficiency: 85% efficient

How to Use the Calculator

  • Battery Capacity : Enter the capacity of your battery
  • Battery Volts: What voltage is your battery?
  • Battery Type: Choose your battery type . If you have a Gel type battery then select lead-acid or AGM
  • Charge Controller Type: Select the type of charge controller that youre using
  • Connected any Load: If youre running any load while charging your battery select accordingly
  • Peak Sun Hours: These are the number of peak sun hours your location receives in a day.
  • to get the size of the solar panel

Types Of Solar Panels

Solar panels are sold in all kinds of sizes, but a 100-watt panel is a commonly found size, especially for RVs. That panel is rated at 100 watts at peak efficiency meaning on a 78-degree cloudless day at solar noon on the equator during the equinox or whats called a perfect day. You get it. With Solar Systems

There are a few different types of Solar Panels to choose from these days and of course, there are Pros and Cons with both.

  • Rigid Solar Panels-are the most common panel on the market and are composed of two standard types of cells called monocrystalline or polycrystalline cells with a layer of protective tempered glass and an aluminum frame. These units are very durable and are used in almost all applications with flat surfaces.
  • Flexible Solar Panels The current flexible solar panels available to homeowners on the market fall under the category of thin-film panels. A thin-film solar panel is made with layers that are over 300 times smaller than standard silicon solar panels, which gives them a much thinner profile and can even make some thin-film panels flexible

They are young and still ironing out problems like mico-cracking and heat dissipation that dont come with the Glass Ridgid Panel Most people believe that just are still unproven in their development but most experts also agree they are considered the Future of Solar the Industry.

How To Calculate The Total Watts That Your Electronics Will Consume

The most accurate way to use a solar cost calculator to calculate the total watts that the electronics in your home will consume is to make a list of appliances you have and record their daily watt usage. For example, if you have a television that is 100 watts and you use it three hours per day, that would equal 300 watts per day.

If youd rather not go around your house to determine each appliances wattage and daily usage, you can also reference your monthly electricity bill. Keep in mind that your bill shows your usage in kilowatt-hours , not watt-hours.

To determine your watt-hours, simply take your kWh and multiply by 1000. If your monthly electricity bill shows that your home used 800 kWh, that would be 800,000 watt-hours for the month or around 27,000 watt-hours per day .

You can also contact your utility company for more information that will help you to utilize the solar cost calculator.

Read Also: How Solar Energy Works Step By Step

Calculating Battery Power Needs

The second step is to determine your maximum power requirement for your RV solar panel. From our example above, we calculated 139 total amp hours are necessary daily, however, it is important to also consider the continuous and peak discharge current your battery is capable of handling. Summing the total watts and dividing by the voltage of your battery will return current in amps if all appliances were in use at the same time: .

Current Calculation: Watts ÷ Volts = Current

If your current in amps exceeds the continuous rating of your battery, you should limit the number of appliances used at one time or increase the number of batteries you have connected in parallel. If you exceed the peak current rating for longer than recommended, the batterys monitoring system will shut the battery down. Keep in mind, some appliances require extra power to start, which would also increase your current requirement for a short time. If you do not have enough current available to cover starting the device will not work. To have a consistent supply of day-to-day power youll need a reliable method of replenishing what you use, which brings us to sizing your RV solar panels.

Solar Panel Cost Per Watt

Solar Panel Calculator &  DIY Wiring Diagrams

After using the Renogy solar panel calculator to determine the recommended solar panel system, you may want to figure out the solar panel cost per watt for your proposed energy system. Doing so will help you calculate whether using solar power will be worth it for your unique situation.

Solar panels come in a wide range of sizes, from as small as five watts up to 400 watts per panel. The cost per watt has to factor in how many panels you need and at which size. In most states, the solar panel cost per watt ranges between $2.25 and $3.25.

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How To Choose Solar Panel Wire Size In A Diy Camper Electrical System

Affiliate Disclaimer: As an Amazon Associate, earns from qualifying purchases..Need Printable/Downloadable Camper Wiring Diagrams?

This blog post will teach you what size of wire you need to wire your solar panels to your charge controller in your DIY camper electrical system. We will cover the technical way to size wire and the easy way to size wire.The technical way to size solar array wire involves using the wire sizing calculator to determine the proper size of wire based on the amps, voltage, allowable voltage drop, and length of the circuit.The easy way involves verifying that 10 AWG wire is big enough and simply using 10 AWG Wire for the solar array wiring.

Calculator For Defining The Number Of Solar Batteries Connected In Series Or Parallel In The Solar Battery Bank

*It is not recommended to connect more than 4 strings in parallel. Instead, increase the standalone battery capacity to decrease the number of paralleled strings. Please have in mind that Adding standalone batteries in series in a string increases the battery bank voltage, however, the capacity remains the same.

-adding standalone batteries or strings in parallel increases the battery bank capacity while keeping the voltage the same.

Other useful solar power calculators:

Also Check: How Big Of A Solar System Do I Need

How To Calculate Solar Panel Size For Battery

To calculate the size of a solar panel for battery, use this formula

Solar Panel Size = + 30%

Battery capacity = Battery capacity * Battery Volts

Make sure to add only useable watt-hours

The extra 30% is added to cover the losses which I have mentioned above

For Example what size solar panel to charge a 12v 100Ah lead-acid battery in 5 peak sun hours?

600/5 + 30% = 156 watts 

You would need around 150 watts of solar panel to fully charge a 12v 100Ah lead-acid battery in 5 peak sun hours

  • Battery Capacity : 200Ah
  • Battery Type: Lithium-ion 100% depth of discharge
  • Peak Sun Hours: 5 hours in Florida city

Winter Proof Your Solar System

Sizing RV Solar – Solar Panels, Battery Bank, & Inverter – Full Time RV

Its no surprise that solar power harvested during the winter months can be drastically smaller than during the summer.

With shorter daylight hours and a lower traveling arc, the sun is just not able to provide as much power to recharge your batteries during the winter.

Though you can mitigate the problem somewhat with tilt mounts, installing a larger solar array system on your camper van can help offset reduced harvesting during the winter. If youre looking to buy, check out our post discussing the best solar panels for camper vans.

Building a camper van? Download our free e-Books with intuitive electrical, solar, and plumbing diagrams.

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How Much Contingency Do I Need

How much contingency you want to include is completely upto you.

Weve always used about 20% and it has served us well.

If you dont rely on your electrical system, consider reducing it a little.

If unsure of your power use or appliances, consider increasing the contingency youll never complain about having too much battery.

You can deduct contingency too by using a negative number. The calculator will warn you the value should be a positive number but will calculate accordingly.

Why Didnt You List All Of The Components I Need Wires Fuses Ect

Your wire size is going to vary greatly depending on how far you are running them. Read our wiring guide for more details on how to size your specific system. It is difficult to predict how much wiring each different van build will have and the lengths needed, and we dont want to have you ordering things that you dont need.

Also Check: How Much Does Solar Cost In Las Vegas

Section : Power Consumption Data

From the drop down menu select battery voltage – 12V, 24V, 36V or 48V. Then enter either watts OR Amps of items that will consume power plus the daily hours the item will generally be used . Column 5 lets you select whether the item is used day and night, just day or just night time. This section is pre-populated with some example data that should be checked and modified by the user for their specific needs.

Calculator For Sizing The Capacity Of The Solar Battery Bank

Solar Panel Calculator &  DIY Wiring Diagrams

*Days of Authonomy is the number of days you need the system to operate when there is no power produced by the solar panels.

**Maximum short-term battery load is the approximated wattage that the battery is recommended to handle within a very short period, e.g. a couple of minutes. However, in the range of several seconds, the battery might sustain higher loads. This is the so-called surge load. Please always consult with the documentation of the battery vendor to get the correct value of this parameter.

Recommended Reading: How Much To Go Solar

Diy Campervan Solar System Complete Guide

You can use a campervan solar system to power a refrigerator, vent fan, cell phones, laptops and all sorts of other electronics. If youre new to solar we recommend starting with sizing your electric system. Our solar system calculator will give you a good estimate of the solar panel, battery, inverter and charge controller size you need.

Our campervan solar wiring diagrams will help you figure out how everything is laid out. If you want to do a deep-dive into each of the electric system parts check out the links below.

If solar panels are too confusing and you dont want to wire the van yourself, we recommend considering a solar generator. A solar generator is a powered box where you can plug in solar panels and electronics. This is a plug-n-play device. All of the equipment is included, its safe to use, and there is no wiring required!

How To Use The Rv Solar Energy Audit Calculator

How much solar do I need? The first step to answering that question is to conduct your solar energy audit. We can do that with the calculator below.

Add every electrical appliance you will need, the wattage, and how long youll need to use it each day to the calculator below. Weve included a few common appliances to choose from to get you started, and you can learn more about finding the wattage of your appliances here.

This calculator will estimate your total overall watt hours per day. That number is the most important factor in identifying the best size solar array and battery bank for your lifestyle.

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What Number Should I Use For Sun Hours

The amount of power you get from the sun is determined by how much direct sunlight your panels get. If you are in the sun more often, then you need fewer panels to charge your batteries.

Basing your calculations at 4 sun hours is a good conservative estimate for most van dwellers varying lifestyles. If you have tilt-mounted panels or are mostly living in a sunny place like Arizona, then you might need less solar watts because youll be getting 5-8 hours of direct sunlight. You are welcome to play around with this number, and even combine it with your winter/summer total watts to see what a comfortable system size is for you.

V 200ah Lithium Battery

How to Calculate Your Solar Power Needs | Full Time RV Tips
100 watts


  • You would need around 570 watts of solar panels to charge a 12V 200Ah lead acid battery from 50% depth of discharge in 5 peak sun hours with an MPPT charge controller.
  • You would need around 720 watts of solar panels to charge a 12V 200Ah lead acid battery from 50% depth of discharge in 5 peak sun hours with a PWM charge controller.

Read Also: How To Set Up Solar Panels For Your Home

How Do I Use This Solar Battery Bank Calculator

  • Enter every electrical device and component youll power form your camper batteries
  • Enter the watts each device uses
  • Enter the maximum number of hours each day youll use the device
  • Select whether each device is DC or AC
  • Enter the amount of contingency you want to add to the total usage
  • Select the battery type you will install
  • Select the minimum expected peak sun hours
  • Select the type of solar charge controller
  • The RV solar calculator provides the minimum size solar components needed based on the information entered.

    Determine How Many Panels You Need

    Of course the size of your solar panel is important but so is the number of panels you need. Skipping this step risks buying the wrong size and shape panels which can lead to an awkward installation. Most solar panels are sold in increments of 10W, so with a little simple math, youll be able to calculate how many youll need.

    For example, an RV that requires 400W of energy means you could buy four 100W panels or two 200W panels.

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    Rv Solar Power Calculator

    Estimating your power use will take a little bit of research and math. To make things easy on you , I built this RV solar power calculatorfor you to use.

    Our estimated daily power use.

    Start by listing out the appliances you will use on the road and how long you expect to use each of them. I populated the spreadsheet with our average appliance use for reference.

    Once you have this list, you will need to research watt usage of each appliance. Most appliances have the max watts listed on a sticker on the bottom or back. If you cannot find the sticker, you can look up the appliance online.

    After you put this information into the calculator, it will estimate the sizes of the solar panel array and the battery bank that you will need to support your off-grid power use.

    Our actual power use by day

    While the calculator is a simple estimate, we found that our estimate is very close to our actual daily use. I included a screenshot from our charge controller app that shows how much power we have used over the last 4 days. We tend to hover right around 2 kWh per day for two adults.

    Cut Back On Electricity Use

    Solar Panel Calculator &  DIY Wiring Diagrams

    If this is your first attempt at sizing your camper solar setup, you may find the result is a pretty big system.

    Living in a van isnt the same as living in a house. We need to be more frugal with our resources.

    The first thing to do is check you have enough space on the RV roof for all the solar panels.

    If not, or the system is much bigger than you expected, its time to reassess you energy needs.

    Try swapping out AC appliances for DC alternatives, look for less powerful devices and replace electric devices for non electrical versions.

    Re-run the calculations above for revised sizing.

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    How Does Rv Solar Power Work

    While there are unlimited ways to customize your solar setup to fit your needs, every system has 3 major parts:

    • Solar Panels – Take in raw power from the sun

    • Charge Controller – Converts the raw power from the panels into a format that can easily be stored

    • Batteries – Store power to use when the sun is not out

    Having these components will allow you to use DC power. Most RVs are configured to use DC power for your lights, water pump, slides, fridge, and furnace. Many newer rigs also have USB ports using DC power to charge small electronics like cell phones.

    If you want to use AC power , you will need to add an inverter to your system. Inverters take the DC power stored in your batteries and change it to AC power that you can use for your TV and microwave.

    Inverters can be pretty pricey depending on which appliances you want to run, so many RVers choose to keep their systems simple and rely on DC power.

    For example, we love our espresso machine and air fryer, and use them every day so we decided to invest in a high-powered 3000 watt inverter that cost us $1100.

    I will discuss the system components in more detail in our post on How Much Does RV Solar Cost, where I will also take you through our setup and help you compare brands to fit your needs as well as price point.

    For this article, it is sufficient for you to know the rough outline of how the panels, charge controller, batteries, and inverter work together to power your rig.

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