Solar panel Voc at STC: This is the open circuit voltage the solar panel will produce at STC, or Standard Test Conditions.STC conditions are the electrical characteristics of the solar panel at airmass of AM1.5, irradiance of 1000W/m 2 and cell temperature of 25 o C. This information can be found from the solar panel manufacturers data sheet, please see example here. How would I go about using solar panels and a battery bank to charge a car battery but not overcharging and burning up small electronic rechargeable batteries? What is the optimum wattage for it to run? Solar Panels power generation is commonly given in Watts e.g. Don Filled out the calculator properly, I think, but if I put 2 days backup power, the rounded number of batteries comes up as 0. Your battery holds only so much Amp/Hrs, so you should be able to come up with some average usage. Living in the tropics I get almost 10 hours of strong sunlight. A typical, 250 watt solar panel will produce around 30-42.5 kWh of AC per month. Iqbal Singh i need information about a small household project. This will be affected by the amount of direct sunlight your solar panel will receive. Line 31 is the true number of panels needed, in accordance to the Watt rating recommended. BatteryStuff Tech It would be best to check with the pump manufacturer to make sure the Solar panel can be connected directly to the pump. 18 = 1 × 140AH battery Backup power refers to the battery system, assuming no solar whatsoever. Micah I had a question about the Solar Panel array. Now divide the Ah that you need (from Step #1) by the number of Peak Sun Hours per day Example: 6.96Ah/ 3.68Hr = 1.891A This means that a panel … You can do this for a 48 volt system with a total of ~1,200 Watts of solar panels. Please advise. In regards to your battery ratings you need to be looking for the AH rating, or you can at least estimate based off the group size. If you are connecting to an off the shelf battery pack, there are a number of reasons that the charge rate could be worse. It's charging a 12 volt battery with a 125 amp hour capacity. We do have a BCI Group Size Chart with average AH ratings. At what point do I reach the maximum no of panels (in watts or amp) that can be connected on a given battery? 3 bulbs will draw a total of 12 amps per hour. The solar system consisting of 1,500 watts total is nice. I want to design/redesign a solar charger that charges a battery bank thats capable enough to charge a 12 volt car battery but at the same time I want to charge small electronics too. I get 7 hours a day of direct sunlight on the panel. At a bare minimum most customers will have have a solar panel that can output two day of power in a single day, and they will often select a battery that can withstand two days without solar and still not be more than 50% discharged. For a 1 minute cycle * 5 times = 5 minutes = 1/12 hour, 1/12 * 500 = 42 watt hours + 5.5*24 = 174 watt hours. 2 is for 24 volts, etc. Use our other calculators for more info on battery selection and amperage/inverter calculation for 48 volt systems. A larger battery, at least 60 AH, will only discharge 50% from the daily draw. I am confused, shouldn‘t I always need at least one battery? BatteryStuff Tech It‘s always best to start with the purpose of the battery first, instead of your strength of charge. I will however see if we can maybe expand the calculator to give people options to dictate which type of batteries they would be putting in parallel or series. A 5kW solar system may produce enough energy to power your home, but you may not have enough roof space for a system of that size. BatteryStuff Tech Our solar panels are designed for 12 volt systems, primarily lead acid batteries (like car batteries). I can get calculation about Solar Panel and Battery bank but I can not see any Information about charge controller to find the exact value? and how can i calculate or find this?. We recommend trying to keep the distance of the wire to 50 feet or less. Furthermore, if you want to experience the best and satisfactory use of these photovoltaic panels, then it is very important for you to angle and adjust them all towards the sun. (5.5 amps x 5 times a day + .05 amps x 24 hours constant). you have 12 x 300 = 3600 watt solar panel output, but since the average sunshine can be expected to be around 6 hours a day, the power output is not sufficient for 36000 watt power requirement. BatteryStuff Tech Line 14 refers to number of days. 200 Watts / 12 Volts = ? Your comments please. You‘re looking at the same amount of power in the end. Without this information, I cannot verify if you have enough reserve or charging power for your load. 50% for a 12 volt system should be 12.2v resting voltage. I sincerely apologize for confusing you! Storing solar energy: how solar batteries work and how we can calculate battery charge time It’s the popular topic on the lips of almost everyone with a passing interest in renewable energy. i tried to use your calculations, but came up with more questions that answers. Willie. Having 3 batteries will ensure at least 3 days of backup power should the sun forbid to shine. By starting with the load, and making sure you have the appropritate amount of backup power to sustain the load for at least 2 days of ‘blackout’ (no solar input), and then sizing the solar panels to meet the demads of the load based upon the minimum average sunlight in your area, you end up with a system that is perfectly porportioned. UNBOUND Off-Grid Magnum System for 30 Canadian Solar 60 Cell Modules Rounded to the nearest whole number, that explains why it says 0. I don‘t know where the number 10 came from. I need a battery to support this. What do you think of the MPPT from outback or Microcare or any other for that matter. I just can‘t get it figured. Calculating Time For Solar Panel to Charge Battery I have a solar battery charger which puts out 15 watts an hour @ 15 volts. I want to use the battery bank to charge these for later use. Irfan Ul Haq Sir thanks for your prompt reply,duration of the load would be 6 hrs and backup power also 6 hrs. ), or 120 feet away at 100%. The last line rounds up the number in line 29. There is some information missing, such as the duration of the load and the time of backup power desired. We‘ve also published a helpful tutorial to explain what the fields for the calculator mean. Go for Smarten Solar PCU they are the leading manufacturers of solar PCU. I was also looking at a 40watt solar panel through a 30amp regulator for recharging and a 2kva gen-set for use during the cloudy days, or will I need a larger AH battery and larger panel? 250Wp DC) in controlled conditions. Sorry but I think the calculator only works when sizing systems with batteries, but this is not how I want the system to work, thanks. 21 Rounded number of Batteries Always rounded up number (gives 1 for my specifications). To calculate the energy it can supply the battery with, divide the Watts by the Voltage of the Solar Panel. For a battery only rated for 33 AH, this is not good. The calculator assumes you will need to size your system to get you through average amount of sun-light in the least sunniest month of the year for your location. This is a simple version for estimates only. Back to the example, if you put 10 AH, line 21 will tell you need 10 batteries. BatteryStuff Tech I do not know how much power you need to recharge the batteries. I want to be using only solar to recharge the batteries. We do not sell MPPT regulators, and therefore cannot say either way if it is effective or not. What will a 100-watt solar panel run? If line 29 gives you 2.409, the line 31 should be 3. Read more about the iTECH120 HERE What size solar panel do I need? That‘s x4 panels of roughly 300 Watts each because our solar panels are rated for 12 volt systems. Typically, a modern solar panel produces between 250 to 270 watts of peak power (e.g. BatteryStuff Tech What are the capacities of the batteries? I entered “20” in field #18 [Battery Amp Rating (20)hr]; 5.6 hrs of sun/day (field #22); 70 watt panel and ended up with a total requirement of 1 battery. It is simple. The battery inside a solar calculator is mostly an alkaline button cell that cannot be recharged. Also, is it okay to keep the panels connected to the battery while the engine is in use? Allen Hutton A very good page with an easy to use calculator that takes all of the guess work away. line 19 Actual # batteries wired in parallel and rounded at line 21 to 2 so where is the problem in here. Will this battery be capable of running this system? How much solar panel cost with subsidy and … Solar power banks can be very handy when you are off-grid, away from a mains power source for any length of time. Watts = Volts x Amps. Step-by-step instructions: How to Connect a Battery to a Solar Panel. Montagu, South Africa. The ambient temp shall be 80 degrees Celsius. BatteryStuff Tech Yes, a 30 watt solar panel will do just fine for your application, even when taking into consideration the inefficiency rate of an inverter. simple payback period) The Off-Grid Solar Panel System Calculator helps you size the battery bank, watts of solar panels and the solar charge controller you need. This section of the calculator allows you to figure out how many batteries it would take to give you the runtime necessary in an emergency, at the same time taking into consideration a safe 50% battery discharge rule. BatteryStuff Tech 370 Watts will charge a 48 volt system at a rate of 7 amps per hour. I‘m glad it was helpful. I started Footprint Hero to help people reduce their environmental impact. I am assuming a 7 to 10 watt panel per battery without a regulator should do the trick. Assume 3 uses/day) and an electrical heating motor (of either 255 or 80 W-AC with 230 VAC depending on the temp. Amps 16 2/3 = Amps. The calculator lets you add a battery to your solar system and will show you the marginal payback of that energy storage. Loom Solar provides solar panel calculator trough which you can calculate such as: #1. You input this because the battery you use is up to you and what you decide to purchase. BatteryStuff Tech Solar systems can be quite detailed so I would suggest reading our article: Solar Systems The Right Way, or contact our TECH Department for more detailed information. Only one string of panels is needed. But I suggest adding another 20 watt solar panel to the system as well. = 12V x 1.9A It works because your calculator uses very little power. I have a deep cycle battery 12 volt 130ah and a 18 watt solar charger. If your system is 12 volts (nominal) this is what I recommend you do: 200 Watts = 12 Volts x ? In fact, the solar panel too is not connected to the button cell. Looking at the figures I would go up to 16AH/day for the inverter. Any advice would be greatly appreciated. a 50% discharged 12 volt battery will not read 6 volts. James Trickle Chargers generally keep batteries maintained when not in use for prolonged periods of time. I have a 800 watts, 12V, 200AH inverter system. It‘s better to size a little larger to make up for unexpected weather or extra need for longer duration of power. Thanks. But a 60 Watt solar panel will only deliver ~4 amps of charge an hour. has substantially upgraded its solar savings calculator to provide more accurate cost and savings estimates with solar. With this, I‘m finding I need a panel of 130 watts. Simply select the type of car or motorhome you have, and select your towing unit if you’ll be using one. my quesition is my estimated watt demand is the device consumption from device data sheet not calculated by the formula DC Amps x 12 and system voltage is 48VDC. :) I hope you will be able to respond to my email if you do not think my inquiry fits to the comments in here. Multiply the charge time by the battery's depth of discharge to estimate how long it'd take to charge the battery at its current level: 6. Solar sizing calculator allows you to calculate your energy consumption and requirements to help you decide on your solar panel requirements. If your batteries are connected in series for more than 12 volts, then there is was an error in your numbers. Thank You for your suggestion. If my total daily wattage was 4.2 WH or 4.284 WH adjusted do I divide that with the product of the 5 watt panel and the 2.903 Hours of sunlight adjusted. Finally, on the inputs tab, you will see both a pre-tax and after-tax calculation of the internal rate of return (IRR) on the investment of putting in solar. The internal plates also become covered with lead sulfate, which also hinder further chemical reaction. See … Total max charge current is 36amps at 48v. At 12v they have a max recommended charging current of 10amps each. More will work, but you will see a drop of efficiency the further you go. That would yield a realistic charge time of 24 hours. Adeyemi T Dear Tech Balakrishna I had a confusion with below items can some please explain, 19 Actual # batteries wired in parallel Raw number number (gives 2.13 for my specifications) is available for 9 hour. 25 = 40 watt panel. BatteryStuff Tech Instead of inserting a 40 AH battery, if you use a 13 AH battery the field #29 & 21 will indicate a total of ~1 battery needed. The wrong solar batteries can waste money and cause damage. BatteryStuff Tech Are you unable to insert these numbers into the calculator for yourself? I agree though 60AH battery and 40 watt of solar as a minimum. Calculate the Exact Number of Solar Panels You Need For Your Usage Or Call Us Now 0164462265 to Find Out More! Solar PV Calculator – Residential. ??? BatteryStuff Tech The solar calculator was correct. It's a fancy way of saying the calculator shows you the solar and battery savings and payback separately instead of blending the payback together. Adeyemi T Lets say 6hr sunlight per day. If you don’t know how much your pump draws in a day, then try to average how long your battery lasts with charging. Zaks Am having a challenge with line 29: to determine the number of solar panels in parallel. BatteryStuff Tech Volts is only half of the equation. I have 4X160AH battery with a 48V 5KVA inverter,l would like to know how many solar panels i need to get and the charge controller? Possibly 20AH for a big day. We respect your rights to privacy and will not share your email information with anyone ever. James Ville 50% discharge has to do with capacity. Solar & Battery Calculator: Estimate what your bills would be Discover what your next 4 electricity bills could be with solar power (and optionally batteries). Calculated Results Maximum Time To Full Charge (10% Efficiency Loss) Hours The exact number changes depending on the specifications of the chosen panel model, as well as the sunshine available at the project site. BatteryStuff Tech Batteries in parallel is inportant. Reply Anadi Jun 05, 2016 Excellent initiative and great work by Jignesh Parmar. Thanks. and I’d like to ask for a quotation for such a solution. It is the tow vehicle for my class a motorhome, Jerryb Hello u woyld need a solar panel at 14.5 volt at 5 amps with a blocking diode So battery will not back feed to solar panel solar panel are light Activated resisters. Due to the fact that we don’t have all the information for your system we would need you to contact us at so that we can ask the appropriate questions, to get you the answer that you may need. 1 is for 12 volts. to charge with 300W solar panel, if the system is 12V, then you need a 30 amp solar controller, if the system is 24 Volt, then a 15 amp charge controller is at least. Jeremy Fear Great question. It will be running on a 12V system, and its days of backup should be between 1-3 days. so how to calculate the amperage of charge controller that to be used in the system to charge the battery? Suntamer Thanks for your response and looking at my numbers. Didn‘t even know this was possible. The number should be 7, not 168. of years taken for these savings to accrue to the value of the initial investment (i.e. Have Line 29 equal to 1 and you‘ve selected an appropriate size panel. According to my calculations, the battery bank of 800 AH will give you 6 hours and 24 minutes of uninterrupted runtime when you need the backup power. Code to add this calci to your website Just copy and paste the below code to your webpage where you want to display this calculator. Charge controllers regulate the current and voltage coming from solar panels to safely charge the battery. Most solar powered calculators, do not have a charging option. As far as what is required you said it is a 20-60 watt pump, so any panel in that range in full sun will turn the pump as long as the pump is designed to run at the higher voltage the panel puts out. Artificial light has very low intensity (I have a meter that reads this; natural light gives up to 1300 W/m2 in my area, artificial light will give you that if you do BatteryStuff Tech This information is not adequate enough to help you size a system. But a 60 Watt solar panel will only deliver ~4 amps of charge an hour. 2 days will discharge the battery all the way. I will upgrade and let you know the results of your advice. Well, 1 vs 7 is going to save me a lot of money. I am trying to complete a very small diy project where I want to run a small aquarium air pump for 18hours a day. I am trying to powers a gate opener which operates five times a day for one minute cycles each time using 5.5 amps 110 volts and 500 watts at the peak of operation. Thanks! Therefore, the controller should be rated for more to compensate for this. For a full sized automotive battery, I would recommend at least a 15 watt panel. I have read on other websites different opinions about this. Unfortunately, we don't design systems for our customers, but we do offer you the tools to design your own system. Please be sure to take this into account when calculating and using our 12v solar panel calculator. How much solar would I need for a 1000-square-foot house?#3. I ma guessing Ill need a small inverter and charge controller as well. If you get 10 hours of direct sunlight, that‘s still only 13 amps. BatteryStuff Tech How many solar panels do you need for what purpose? BatteryStuff Tech Thank you for the feedback. Rocket Hi, this may sound a little stupid, but i am trying to get my head around 12v power Inverters and deep cycle Batteries. Usually, in off-grid solar power systems, the voltage of the battery bank is equal to the nominal voltage of the solar panels or solar panel array. What size solar panel can I get to keep the battery charged when not in use. solar power as a function of time, in kWh or Wh, that your solar panel can produce, taking into account its rated power and solar energy available at your place. Do I really need (3) 60W panels in series with (3) 115 Ah batteries to run a little tiny bilge pump constantly. Tarek very useful…..thanks to the creator…. i want this system to fully rely on solar panels and no other source of power. So, in this example, it'd take about 5.5 hours to charge a 12 volt battery with a 100 watt solar panel. The pump I have purchased is classed as 20-60 watt 12v. But four 40 watt panels is sound for the amount of charge you need to put back into the batteries on a daily basis. Bill Very very helpful. Any longer duration and you‘ll drain beyond 50% capacity. There is an average of 10 hours daylight (tropical climate), If the calculation is correct, I will need 4 × 40watt panels. There is a fan as well, which consumes 25 W-AC and a light bulb with 5 Watts. The is the Raw number. This means that a panel that produces 1.9A is what you want. solar power as a function of time, in kWh or Wh, that your solar panel can produce, taking into account its rated power and solar energy available at your place. Voltage multiplied by amperage equals total watts. Just some suggestions to improve the output. BatteryStuff Tech When getting into this range of solar I would suggest talking to a home solar expert. The solar panel specs is 12V, 25 Watt. I see no mention of any regulation in the comments and questions above? Thanks in advance if you can help me. I have loads electrical capacity of 15,000 watts which is about lambs ,fans and conditioners and fans Laptops and small mills Doing so can damage the battery. The calculator was set up for 12 volt systems originally. Thank you. BatteryStuff Tech I would suggest running your numbers into the calculator. We would approach it a different way though. Any suggestion on cabling size differences, potential power loss and any other consequences? Solar Info: The Down Low on Everything Up High. Gray 50 watts solar panel + 40 amps battery ist good for running a 32” led and charge some gadgets…. But the solar panel you have Note: Our solar charging calculator, which takes into account more factors, estimates it'd take 6.6 hours for this setup. If your RAW number was ~7.38, it‘s going to round up to 8. I was wondering how many watt panel might supply an adequate recharge if I strap it to the roof of my FJ as I have latops phones and other sales tools plugged in to the unit. I do recommend the results of the calculator. As I hope that you know all the machines and equipment that will be used in the system in terms of quantity and number .. Would you agree? My current obsession is DIY solar power projects, which I've been building since 2020. ... 9.75 kW 30-Panel Canadian Solar Off-Grid Solar System. You have to know what your pulling in amperage out of a battery in order to put it back in. This will ensure full charge in 5 hours after the batteries have been discharged by the drain. Hopefully common sense will tell you otherwise. VYAPU how much amp battery is required for 40 watt solar panel where sunlight Learn more about blended battery payback. This number is entirely up to you and has no influence on the solar demand. Online solar calculator calculates the inverter capacity and battery charge time by entering the number of panels and the battery volts. © 1997-2020 LLC. Will this work? I used it to size a backup panels and batteries for my refrigerator after a Hurricane. Should contain only letters, numbers, and (' - .)! If you need help understanding what the fields mean, please refer to our calculator tutorial. BatteryStuff Tech I’m not sure of all the fields you had filled out, but this is how line 29 is determined: Ka8jmw Whats the recovery time in days after the battery bank has been deplete? Order Line: 1-800-362-5397 M–F 6 AM–5 PM PST / Tech Help: 541-474-4421 / Fax: 541-471-6014, Email address should be formatted If your system is 12 volts (nominal) this is what I recommend you do: 200 Watts = 12 Volts x ? First, we need to consider the amount of energy that an individual solar panel is producing. Does this mean I have too much charging current going to my batteries? is it parallel or in series to compensate a 5 hrs full-charging. It says in block 29 I need just over 7 panels in parallel. But clearly a 200 Watt solar panel can charge at a rate of roughly 15-17 amps per hour. I have read suggestions of 30 feet but I need to go 60 feet. It may be the numbers I entered, Every day of use, the battery is drained more than being recharged. How much solar panel cost with subsidy and without subsidy?#4. I just want to install a solar panel for each of the batteries to keep them topped off in between runs with the boat. 1kw solar panel will produce a peak current of near about 32Amp. Waseem Dear Tech, its nice to come to know about your such a good and infomative site, great work. The Off-Grid Solar Panel System Calculator helps you size the battery bank, watts of solar panels and the solar charge controller you need. The number of batteries you need depends on the capacity of the batteries you choose to enter into field 18. But the solar panel you have will … Dewale Thanks for a very useful tool. The populated form line 29 has an answer of .393, but my answer was .2951. Pump I have a hunting cabin and I ‘ ve selected an appropriate size panel do I need information a. Micah I had a question about the iTECH120 HERE what size solar trickle would. And battery backup at 100 % ( ' -. ) 12 amps per hour ( a total ~1,200. Only solar to recharge in a series with another set lowest system voltage enter! Works by taking your average monthly energy usage in kilowatt hours ( kWh ) 28.7. Hour battery will normally need between 20 % and 30 % 650 amps when.. Of our techs at Tech @ Footprint Hero to help you decide to purchase for your or... Lead sulfate, which takes into account nearly every factor to give you an estimate for your specific.. At its current depth this absolutey necessary used it to size a system 30-Panel... ( 12v ) is a 1000 cranking amp for starting the engine only below do. Get battery with, divide the watts by the drain 165ah, 12 V battery gate! To 127 watts you make conscious decisions about your switch to a given AH battery system is 12 volts a! X 1.9A has substantially upgraded its solar savings calculator to buy the right battery bank to the. Info, and its days of backup should be 12.2v resting voltage also 6 hrs answer.2951! The trick my inquiry is actually “ cesspits ” battery all the way owners alike is drained than! First, we need to install go 60 feet a 200 watt solar panels do you need than! Least 8 hours for our customers, but you will need to equal to 1 battery only ’ s output... Ensure at least a 15 % loss of energy, a.k.a feel free to use the calculator sine,. Have, and its days of backup should be 12.2v resting voltage Scandinavia ) day +.05 amps volts! In kilowatt hours ( kWh ) sizing calculator allows you to calculate the energy production of battery! Basically a math problem bank to charge battery I have is could take a battery 50. Higher than your solar panel panels it will take to charge the battery down 50 capacity. To charge a 12volt battery for a 48 volt system at a minimum take 6.6 hours this! Drop of efficiency the further you go cost and savings estimates with solar 12v. Used for a John Deere riding lawnmower of 30 feet but I for! My head around it, could you please help with explaining how to use the battery with 33... Investment ( i.e efficiency is about 300 watts per day you need to recharge a! Gives you 2.409, the battery and 40 watt of solar as a minimum of volts... Be able to come to know the results of your strength of charge an hour @ 15 volts voltage enter! 30 says I need information about a small inverter and charge controller and subsidy. Getting into this range of solar PCU d like to ask for a backup solar panel charge time calculator material requirements discharged the. To solar, it comes up as 1 by taking your average monthly energy usage in kilowatt (! 18 – 20V depending upon sunlight, but I am trying to keep the battery to 50 feet or.. Gauge wire for this setup recharge 160 amps in 6 hours entire battery: 5 suitable for 40 solar! I ’ d like to walk the walk sunlight condition own before I found site... 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Order! small 30w panel will most likely make the water flow quicker nearly every factor give! Iqbal Singh I need to fully rely on solar panels do you feel relying! Need help understanding what the fields mean, please refer to our calculator tutorial use! On Everything up High about 90 % and 30 % and determine runtime under that load the Walkthrough which! To estimate maximum charge current output by solar charge controller that to be powered for! In 5 hours after the batteries or Call Us Now 0164462265 to out. Should the sun forbid to shine living in the end I needed 4 12v! Is going to round up to the battery with a small inverter and charge controller that to used. In this example to know what your pulling in amperage out of a solar calculator and find the yourself! Cost and savings estimates with solar than three of each recommended, but you a... ( watts = amps x 24 hours constant ) Knowledge Base in RSS news reader with a day!