How Many Solar Panels to Charge a Battery?

[@cleversolarpower]

📖 My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified 🎁 Free Diagrams: cleversolarpower.com 12V 200Ah 5% discount EU use code 'clever': cleversolarpower.com/go/eu/red12V200Ah 12V 200Ah 5% discount US use code 'clever': cleversolarpower.com/go/us/red12v200ah

[@Paul-l4b3r]

Why did you use 14.4v when calculating the size of the controller?

[@benjaminmubanga6604]

😊

[@tgj1313]

do you have your book in Kindle format?

[@Whitecubes-x8x]

How many hours is the charging time when using 400w solar panel?

[@Cgconst1]

Nick, you have the best off-grid solar channel of all. I know because I’ve watched all of them. Please continue doing these excellent videos!

[@cleversolarpower]

Thanks, more coming soon 🙏

[@lowflight2]

Question: Why when two 12volt agm lead acid vrla batteries are connected in series the battery connected to (-) line is loosing always more power and presenting thus a lower voltage than the battery connected to the (+) terminal ?? And how can we stop this from happening?

[@bigwebbs4925]

For my boat i use a 160watt solar panel with my 120ah lithium battery and it keeps it charged no worrys when in use. I only run a 54p watersnake off it with no worrys at all. But be diffrent if your using it consistently..

[@juanplus3324]

Thank you! You explained it so clearly. Time to make my own solar generator.

[@cleversolarpower]

Glad it was helpful!

[@owolabiadeteye5919]

Excellent lecture, thanks boss

[@EwenMackenzie]

this is incredible! thanks for making such a nice and simple video

[@cleversolarpower]

Glad you liked it!

[@sejac1232]

Where are you getting the 40 volts from in the wire size calculator that you show at 4:47 in the video and the current in amps?

[@MWR-lg9qp]

I just thought I had a basic understanding of solar system design. Your content is very informative and is helping me better understand proper system design. Thank you.

[@cleversolarpower]

Thanks for the sub! Welcome aboard.

[@nomsTube]

Hi Will a bigger panel cause issues? For example if sunny days you are getting 6 hours of sunlight then 400W solar panel would generate too much power. Will that be a problem for the battery or the charge controller? Do we need to adjust the charge controller? How many amps max to charge a 100ah lifepo battery? Can a 30A charge controller be too much and fry the battery? Can the better be charged directly with panel and solar charge controller without inverter?

[@taqarii2456]

thank you for all of your work

[@cleversolarpower]

Thanks for watching!

[@BarrioBarranco1]

It says where I live at 57N, even with the tilt adjusted to 45 degrees the solar radiation is 240 WATTS per metre squared per day.... so presumably it just isn't worth installing solar...

[@Alexander-o9x]

Question: Where did you get 14.4V in the wiring diagram @ time 4:13

[@cleversolarpower]

Charging voltage of a lifepo4 battery. Now I would use 12.8V as the nominal battery voltage.

[@lisac6609]

I want to purchase a 12.8V 300 Ah battery to add to my Ecoflow Delta Pro (3600 W). I would like to recharge the battery with a 720 W Ecoflow generator while it is being charged by a 400 W solar panel. Can this be done? Also, I live north of Houston if that is a factor. Thanks and I learn a lot from your videos!

[@KerbyDaFrog]

Always great info!

[@cleversolarpower]

Thanks! More to come.

[@micahthompson3762]

Appreciate your thoroughness on this topic.

[@MohdRipin]

Thanks goods info for my next solar project.

[@einyv]

Just a question let's say you have multiple powerstations with varying specs for solar input. Could you theoretically have 1200 watts of solar, using the appropriate mppt controller and inverter and plug the powerstations into the inverter to recharge?

[@cleversolarpower]

I don't think so. The charge controller needs to see a battery. I have never tried, but doubt it will work. Better to have the max amount of solar connected to each power station.

[@brianbassett4379]

I use a 300W SunCapture folding panel with an MPPT solar charger to charge a 58.8V 40Ah lithium ebike battery. On a cloudless day, it charges (at least) as fast as it does using a Girn Satiator using 120V/240V at 8amps. It takes approximately three to four hours to charge from 20% capacity to full.

[@vittalkoppal]

Excellent explanation very informative and quite easy to understand. 🤣👍 Thanks.👌😃🤗

[@cleversolarpower]

Glad you liked it!

[@jamiem8356]

Hello, may I know the reference of the formulas that you used in the computations? I'm going to use this for my project thank you very much!

[@cleversolarpower]

Experience and electrical calculations. It's all in my book.

[@baymax6894]

What is your thoughts on gel batteries? Im wanting to setup a system for my wifes parents farm in the philippines. I'm going to buy things from shoppee to make this happen so im going to buy your book.

[@bhongvlog-u4l]

can i connect series with the 240w and 200w solar panel?

[@Rezail_Uhhh]

So when really sizing for a battery, I would have to take into account the inverter, the house daily draw and the recharge rate for the battery?

[@cleversolarpower]

Correct 💯

[@First-y3r]

Hi Nick, i have a food truck that i wanna use a 5000w inverter. How many solar panels, what amp voltage of solar panels charger amp and batteries voltage will need. Thank in advance

[@CDragonSMOK]

hi, i have one question. I have car with soft top. So in the winter its in garage. Can I use PV to keep the battery charge without damage? I mean, is it good for battery to be 100% charge all the time? And is the charge controller and PV all what I need?

[@cleversolarpower]

Yes, solar panel -> charge controller -> battery. Lead acid likes to be at 100%, lifepo4 better at 30-70% for long term storage. You can adjust charging voltages to limit charge to A specific voltage.

[@khieusovannara2281]

Lovely to watch but getting sleepy when there are a lot of number and started to remember the premary school. But don't worry I already subscribed

[@cleversolarpower]

Yeah, my videos are good for falling asleep 😀. You should watch the one about load calculation. You will be in for a treat.

[@sejac1232]

Is there a website for the wire calculator size that you show in your video?

[@cleversolarpower]

I don't like wire calculators because they can differ with insulation temperatures for the wires. Instead use the data from the manufacturer.

[@philron5758]

Thank you for making it easy, i just bought your book.I am new to solar energy and i am trying to setup a system in Honduras. I have a pump (340w, 3.0 amp) that i need to run 2-3 hours a day. My setup is with a 12.8v 150a gel battery, a 100amp controller and 400 watts of panels. before i blow anything up will this work? any help is appreciated. Cheers PIP

[@cleversolarpower]

My book will help you create a load analysis. I recommend using lifepo4 batteries, they are much cheaper in the long term than lead-acid.

[@EsaintTv]

You did not link da pvwatts website in da description 😒

[@edwardcouch9969]

He did

[@EsaintTv]

@@edwardcouch9969 ahh I c

[@robertkat]

Depending on if it is summer or winter. Who shovels snow off the panels at minus 25 degrees and a foot of snow on them?

[@cleversolarpower]

It's a great hobby. You should try it sometime 😄

[@duncangilmour6250]

When calculating the cable size, how do you get to 10AWG? The calculator in the video shows 40V and 13.12A. How did you work out those values, please? I would have thought they would be 60v and 7A (400w/60v). Thanks

[@cleversolarpower]

vmp = 20.2V Imp = 9.65A two panels in series = 40V @9.65A*1.56=15A (it should have been 15A instead of 13.12A -> my mistake) 1.56 is a safety factor for outdoor cables, otherwise it would have been 1.25 for indoor cables.

[@sejac1232]

@@cleversolarpower Ah Ha, you were getting the info from the solar panels, I see, thank yuo

[@michaelkaniki5616]

where did you get the 500W/msq?

[@cleversolarpower]

Random, if you take a W/m² measurement device and hold it in the outdoors it can have 500W/m².

[@ezoguan]

What will happen if I use a 20amp mppt charge controller?

[@cleversolarpower]

Then the max charging current will be 20A

[@mikemosc3254]

you should do the same for how long can you run an air conditioner on your batteries. with the assumption that the person gets something more common like a 12 thousand btu model. I'm trying to explain to a customer of mine that putting them on batteries along with her house would be a whole lot of extra power and battery storage that could otherwise be avoided by running a generator for a few hours a day. but she wants them to last all night. i am personally not sure about the surge wattage and so i can't tell her exactly what to do.

[@cleversolarpower]

running ac on batteries can be done, but its expensive. I don't own an ac so i cannot tell accurately.

[@mikemosc3254]

​@@cleversolarpower i used the calculator on your website to show her that trying to design a system that can run two 21 seer 12 thousand BTU ACs( estimated to run at 571 watts apparently though im not sure for the surge) for 12 hours a day, with 3 days of autonomy would be prohibitively expensive. so i managed to convince her to keep the air conditioners for when they run the generators or to build a seperate solar array and battery bank for each one individually. i did that in part due to my fear and lack of knowledge in estimating larger systems. i don't know how many batteries in parallel are too many. particularly in regards to LiFePo4. i know for Lead acid ones going past three strands in parallel is not recommended due to the uneven charging as a result of the resistance in the connectors, and the subsequent formation of eddy currents. and i know that the BMS for the lithium batteries will help to mitigate that, but i have no idea how far that goes for them. like if her battery bank is 48vdc,583ah, i say 6 48v 100ah batteries, but she chooses to get the bigger system so she can have extra power leading to the system to become 48vdc,3212Ah, does that mean she should get the 32 batteries? ( we assume she has the money to do this at this point)

[@Fatfreddy7]

Hi Nick what if I have a 300ah 12v lifepo4 and can charge it back up over 2 or 3 days then I won't need 3 x 400watt panels, maybe I can swap out the battery with another 300ah battery?

[@cleversolarpower]

Off grid design says you should be able to recharge the battery in one day. Otherwise, you don't have days of autonomy. If you want one day of autonomy, then you can spread the charge over 3 days.

[@Fatfreddy7]

Ok thanks, that makes sense

[@kunalpagar5465]

Nice information. If I have lead acid battery with C10 rating, then can i charge the battery in onday. You can consider 100Ah 12volt battery

[@cleversolarpower]

Lead-acid batteries are generally C20 or 0.05C. C10 is 0.1C so: 100Ah*0.1C= 10A max charge for optimal efficiency (no heat generation). 400W/14.6V*0.8=22A. 0.8 = actual power generation at noon with sun. So you should have 200W.

[@kunalpagar5465]

Thanks for reply.

[@michlardot2215]

So if i have 2 12.8 volts 100 amps lithium life po4 batteries i need 800 watts of solar or will it stay 400 watts of solar when i put them in parallel? Greets from belgium

[@cleversolarpower]

If you double the battery capacity, you need to double the solar. Greetings from Antwerp 😉

[@nurturaanimae]

This chanel help me a lot by giving a scale and begining point . It is obvious i will need to adapt theory to reality as it is. Let see :-) Thanks for this chanel ! In my opinion, connecting in parallel costs more but gives more stability. Shade somewhere or one panel kaputt doesn't disrupt all the system.

[@cleversolarpower]

True, parallel is better for shading. But more expensive. Mppts have a max input current as well.

[@The_wandering_troubadour]

Im learning and about to upgrade to Lithium ion batteries, BUT now hearing about 25v holds higher wattage???? What does this mean? I have 4x100watt solar panels. If the 100Ah 24v nattery holds double from the 100 12v does this mean i can't run something higher than 2560wh appliances? What if I had 2 24v 200ah batteries? Im wanting to run music gear some LeD lights and 38qt fridge freezer in my trailer and wish to have at least 800Ah and was going to buy the 230ah, 280ah, or 300ah single batthery and slowly buy tue rest later.

[@cleversolarpower]

Higher voltage does not hold higher wattage. A 24V 100Ah battery holds double the energy than a 12V 100Ah because if we multiply them we can see they hold more energy. 24V*100Ah=2400Wh, and 12*100Ah=1200Wh. Wh or watt hour is an indication of energy stored, not power. I suggest watching my video about 12V, 24V or 48V battery systems.

[@The_wandering_troubadour]

@@cleversolarpower I decided to stick with a 300ah battery at 12volts. I watched a video by Will Prouse and got me so confused and frustrated as he said Id need 24v panels and all this other stuff so its easier to just stick with 12v and a 300am Lithium Iron battery. I already have 4x100watt panels with a renogy 40 amp Rover conrtoller and a 700watt inverter. I dont have the luxury to build any new system either, Im' in a van on a fixed income.

[@darrellwalker5203]

Keep what you got.add to it little by little.do your research not just one either look at everything in multiples.​@@The_wandering_troubadour

[@saikhunkhay3617]

Thanks for your knowledge sharing.❤ What to choose series or parallel for solar panel?

[@saikhunkhay3617]

Sorry i mean how to choose 😅

[@cleversolarpower]

Search my channel for series vs parallel and you will find a video about it.

[@itzzyanibg3060]

Amazing explanation. For example, if I use 90Ah battery and after the calculations, it says that I need a 350 (about) watt solar panel, will it be a problem if I use a 410 watt one?

[@cleversolarpower]

Thanks, glad it was clear. Of course, the more the better. If it's a lithium battery, then you can charge with 90A max.

[@itzzyanibg3060]

@@cleversolarpower i cannot find good priced lithium batteries. Looking for a budget better option

[@akhan8456]

Hi, Why are you not taking 12.8 V instead of 12 V during the calculation 12V x 100 Ah x 0.5??

[@cleversolarpower]

The nominal voltage of a lead acid is 12V, not 12.8. lifepo4 is 12.8V.

[@hillarymure530]

Which inverter in good for 200ah battery

[@cleversolarpower]

if it has a 100A BMS, and a 12V system, then you can use a max of 1200W. If you have a 200A BMS, then you can use a max of 12V*200A=2400W.

[@NigelM18]

What about solar panel voltage? Mine are 40v voc I've seen 24v voc and of course 12v too.

[@cleversolarpower]

You replace the voc with the value of your panels.

[@NigelM18]

@cleversolarpower that's my point. So a 40v 200 watt panel is almost 4 times better than a 12v 200 watt panel then right?

[@stevenjohn350]

@@NigelM18 did you get an answer to that last question..?? Because my best guess is. NO . as its not 4 times better, its just more useful if you need 40volts, because the "work" or "energy output" its going to do, is still only 200 watts.

[@NigelM18]

@@stevenjohn350 ?? A 40v 200w panel after it goes through the scc converts it roughly to 12v 700 watts.

[@HighCountryLiving]

The amps of the panel would be lower for the higher voltage. Together, they still have to be 200 watts.

[@SpaceSoftSystem]

how we charge lithium battery using dc wind turbine , or how we charge lithium battery using synchronous dc motor , share full details with controller and generator details

[@cleversolarpower]

Please?

[@rajaovelonaandry102]

can you explain MPPT and PWM please

[@cleversolarpower]

I made a video about it already. Check it out on my channel.

[@rodneysingh283]

Thanks great info but I noticed that either your calculations are incorrect or there is some information missing for example 1280x 3.5 = 4480 and you had 365 am I missing something

[@Crisis-1837]

Divided by, not multply

[@speedygonzalez188]

How many panels i need for a 460ah lythium battery. With 5888 WH. To charge it in 4 hours? Thank you.

[@stevenjohn350]

that is more than 100 amps per hour.

[@wandaclark6277]

How long will a 12 volt 100 ah power a mighty mule gate opener solar

[@cleversolarpower]

replace the power rating from this video with the power rating/usage of your gate opener.

[@alfredpfattischer556]

Can a 48 V barrery replace 4 12 V batteries connected in series ????

[@cleversolarpower]

Yes

[@kimmer6]

I'm fine except from November through February. Short days and low sun angle really hurts.

[@khajask8113]

250watt panel.. which battery lithium battery suitable..?

[@cleversolarpower]

250W*3 sunhours =750wh. A 12v 100ah battery is 1280wh.

[@trishaturnr-iw8hm]

I do not understand solar what so ever , I just can’t comprehend it , I have solar on the go 20amp hookup on top of my Rv , All I need is a simple setup to keep my deep cycle Rv 81 ah battery charged , I’m willing to get a new battery of what’s ever is the best battery , I just need help getting what I need to keep the battery charged , that’s it just so I can go in and check my Rv out at night when I just need to check my mouse traps I have set out , But every time I turn around the battery is dead, have no way to charge it with my battery charger , no electric nearby period . Can you help me out please on what I need to buy to accomplish this , I can do the hookups no prob .

[@cleversolarpower]

If you go to my website: cleversolarpower.com you will see a few diagrams. The size of the system depends on what you want to run. Therefore i recommend watching my video about 'how to size an off grid solar system'. Check out my other videos as well. I made a playlist for beginners and a playlist with 'systems'. Alternatively you can get my book as well where everything is explained step by step.

[@mikegto65]

Great info

[@cleversolarpower]

Thanks for watching!

[@MPTran-pz1gm]

great video

[@cleversolarpower]

Thanks!

[@mohdzamrizakarialann_zamri4423]

tqvm

[@aivosha]

how to combine solar and battery charger together to charge the battery ?

[@cleversolarpower]

Just wire both to the battery. Checkout my diagram videos to see examples.

[@aivosha]

@@cleversolarpower Can you have both sources charging the battery at the same time ?

[@BrendaMwakachienyi]

Can I use solar panel direct to the battery without a controller

[@stevenjohn350]

@@BrendaMwakachienyi A controller is usually recommended to be safe and effecient.

[@charleshatcher4150]

Is there anyway to charge battery with a solar generator

[@cleversolarpower]

No, you need a petrol generator 😄

[@NadoJoe]

Awesome video I appreciate it. Got a new subscriber. Keep up the videos everyone learn something. A question I have is my lithium lifepo4 batteries. They are all 12v 100ah batteries. First question is to charge those types of batteries is there a maximum amps that should be used to charge these? I know that the more amps the harder it could be on the battery instead of slow charging it but I would like to know if I want to get it done quickly bc of time what is possible? I also wonder if having them together in parallel changes this answer or if in series if it changes anything? Another question I have is in regards to the possibility of having two batteries in parallel and the third in series so I have a 12v 200ah section and a 24v type or would this just make it all uneven bc it is not the same AH and would need to have the 3rd battery be a 200ah 12v battery to work if it’s possible? Thank you

[@cleversolarpower]

It depends on the BMS of your battery. Most batteries are 0.5xcapacity or 1xcapacity. So in your case 50 or 100A per battery. Series and parallel splits the current. No you cannot, you need two seperate batteries.

[@NadoJoe]

So if the bms is the same as the AH you can use the same amps to charge it? So for the example it would theoretically take only an hour to charge one? I’m assuming that doing this all the time would be horrible for the battery. What would you do if you weren’t in a hurry but maybe getting ready for a trip and needed to get them fully charged? Also to make sure I get your response about having 3 in parallel, if they all have the 100bms and I charged at 100 amps it would split evenly among the batteries so 33.33amps each? And take 3X longer approximately?

[@ossamanasr5200]

You are amazing

[@sdatt4761]

Sir a 1 kw solar system is 4 unit in a day how ?

[@cleversolarpower]

By unit I assume you mean kWh. If you have 4 sunhours, then a 1kw solar panel system will produce 4kwh or 4 units of energy.

[@Celzot]

Im in Houston TX

[@kevinouterbridge3300]

I have 7000 batteries bank how much solar panels I need

[@prayforthe_1644]

3:49

[@leeinwis]

3.2 ?

[@davidmann4533]

Way too complicated for me I’ll just keep paying my electric bill which is never more than 260 for two months😂

[@vitovitale8325]

@davidmann4533... I agree that (for myself) & I don't know why, but this subject is hard to wrap my head around, I guess out of curiosity or just a want to understand how & why things work how they do; not just this subject but other subjects too; must be thick skull or a subject over my head, but for some reason I spend a lot of time beating my head against the wall working on understanding this or other subjects; my father loved tools buy them all the time; but he never really knew what to do w/ them (much ❤️ Dad 🙏) besides ever getting to thinking things out in like some series of logical steps

[@cleversolarpower]

If you are grid connected and there are no blackouts, then keep using the grid. It's the cheapest. 😉

[@webberfan1234]

Hahaha.

[@maddie690ify]

Solar is a great solution for people who decide to live in places where there are no other power options(off grid). It's more expensive and complicated up front, but maybe the only option. It's also a great option for places that are prone to natural disasters and fuel shortages during those outages.

[@mfnp99]

Its 0% to 100% ,but for the best make it 80% usage

[@cleversolarpower]

Before I would agree, but now i disagree. Since most lithium batteries are now 8,000 cycles, it will take 22 years for them to reach 0 cycles (if you cycle every day from 0-100%). And then the capacity is still 80%. So it's actually more cost effective to use them from 0-100%. Like Will Prowse says, calendar aging will destroy these batteries before the cycles are met.

[@mfnp99]

@@cleversolarpower really 8000 cycle for LifePo4?

[@cleversolarpower]

@@mfnp99 Yes, check the datasheet for lifepo4 cells.

[@mfnp99]

@@cleversolarpower i have LifePo4 12v 100ah for MINI SOLAR SYSTEM, but the Voltage stuck in 13.2v or 13.3v

[@alals6794]

@@cleversolarpower Whoa.....didnt knoe that. Thanks

[@Bob-p2q9q]

? What? You can buy a phone solar charger to charge that battery,just gonna take a while,if you want to charge it quicker gonna need couple of panels,thats wants great about building your own system, you can add on ,don't need to buy everything at once

[@cleversolarpower]

A phone solar charger with a 12V 100Ah lithium battery? Good luck with that 😉

[@cleversolarpower]

A phone solar charger with a 12V 100Ah lithium battery? Good luck with that 😉

[@Bob-p2q9q]

@cleversolarpower I think alot of people don't understand the relationship of the panels to the storage,vs their needs,I use solar to power one room of my house every day,3 100 watt panels generally keeps me going no problem, however if I just use my system for power outages that normally occur in my area,last power outage was about 6 months ago,lasted about 3 hours,I could have put a small solar panel to it and be fully charged by now,a lot of people seem to think for occasional power outs they need to spend alot

[@BuckQweet]

Where did you come up with 23.7 volt?... U need to include all the mathematical figures. Cuz it looks like ur just throwing numbers out there.

[@cleversolarpower]

It's written above in the formula. It's the Voc of the solar panel.

[@klmkt4339]

❤

[@kennethhuff8296]

😮🤔.😢..🥱...😴🌀

[@cleversolarpower]

That's a lot of emotions for one video 😄

[@medilax91]

Still you did not make it clear explaination.. 😂😂😂😂.. Newbie like me got nose bleed.😅😅😅.. You should clearly say every end of the explaination thar therefore, each 12v/100ah you need blah,blah,blah panel watts and blah blah blah SCC... not no need to mention.. technical term.. 😢😢😢😢

[@AllodialTitle]

It's not difficult.

[@cleversolarpower]

I do my best to make it easily understandable. If you don't understand it the first time, i recommend watching it again. Then you will get it.

[@grahamjohnson4702]

These are all calculations based on your assumptions now please do one on a realistic case. I want a 2 unit air conditioning system and I want off grid solar, I want one unit working in the daytime and the other at night, so what full system will I need. This is the problems we need not all your calculations, or is that all you will do on the videos ?

[@kevsip1002]

Buy his book. Thats what I did.

[@Fatfreddy7]

Do your own assumptions then

[@fibber2u]

The information you need is in his videos. Watch them, think about it and then use it.

[@grahamjohnson4702]

@@fibber2u I am not an expert on electronics and calculations, so I am unable to do as you say, it is OK for you electronic experts but not for dumbos like me, we don't all understand these calculations

[@grahamjohnson4702]

@@Fatfreddy7 How can I if I don't understand how he calculates, not everybody that wants air conditioning via solar is as clever as he is.