🎁 Free diagrams: cleversolarpower.com/free-diagrams/ 📖 My best-selling book: cleversolarpower.com/off-grid-solar-power-simplified

This is really helpful, thanks for explaining it. I am just about to DIY a solar and battery system !

Very clearly explained with good graphics.

Your book was the 1st one I bought on the subject of Solar Power. I bought others, but kept referring back to yours for a simple clarification. The content and ease to follow on the various subjects is excellent. Many Thanks 🙏🏼

Yea, I agree it's best to size the inverter to a margin above the expected peak load. The total battery capacity would be determined by the expected average load, as would a solar array(plus a region/sunlight-based margin) and battery chargers. Oversized inverters for a modest average expected power consumption has little effect, other than the idle current used to run the circuitry.

Very useful. I send it to my clients when dealing with what's needed in there RVs.

Thanks for going thru the math with us. I for one are very great full. Keep up the great work.

Excellent explanation. ~Thank you

Thank you for the video and for the diagrams. I have been having trouble finding out and understanding this information, liked and subscribed!

That’s the best video that I have ever understood on battery set up !

thank you i was abit in the dark now i can see the light i am more confident to start purchasing my batteries and inverter

You actually sound like you know your subject ! Congratulations ! I have my doubts about many presenters on this platform as they often do not sound confident . Have a great year & life ! I will be buying your book , I bought Will Prowse book but when Amazon did not fulfill after payment was made, Will ignored me.......

Great info, thanks for sharing buddy!

Very good lesson in battery usage!

Very excellent description indeed

Good information. I would add the DOD factor to point out the differences in the chemistry's

Thank you so much for sharing 😊

Great information! Thanks for sharing.

Thanks for information long time ⌛️ asking from many people my mind on settle ❤

Very helpful thanks 👍

thank you

That was Great. I do like the product link and explainations.

Thank you so much!

The 12V 100Ah Renogy AGM Battery you pictured far out paces your C-rate calc of 20A. It is rated at 30A with a 5 second rating of 100A! A couple of these tied to a 2000W inverter works wonderful in a typical RV.

I have a 20w solar panel, 30a charge controller,12v 7ah battery and a 200w inverter. Is using the 7ah battery with the 200w inverter to charge my 33watt phone ideal

Great explanation. I'm saving this video to my favorites list.

Wonderful video with everything broken down. Thank you, a question, though. Are the calculations for the Lead-Acid battery the same for AGM batteries?

Great Info, much appreciated. The 80 amp fuse conversation confused me? May I please ask if this set up(4 x 12v 100ah) works for a 4000 W inverter. I ask because of the fuse situation and needing more than the 80 amp fuse you discussed?

Have not installed yet I purchased a 3000 W inverter that will handle a 6000 W. I don’t recall the amount of time but it’s a start of it for starting large motors and things load.

"Limit current to 100 Amps..." This is why I shall do a 36V system. And your explanation of the C-Rates of batteries explains why those Telephone Central Office Backup Banks I installed were so huge. I'm a retired electrician, and, frankly, managed to miss that day in class.

I installed a 3KW pure sine wave inverter together with six 110 AH 12 volt leisure batteries wired in parallel on our boat six years ago. I didn't do any calculations. It was just my gut feeling of what was needed. We have a 230V fridge, a 230V 26" LCD TV, a 230V microwave, a 2KW 230V Electric kettle, a 17 inch Laptop PC run with a 230V charger and can go away from the mooring for a week at a time and run those things with no issue. We do have a diesel powered, 12 KVA generator installed too but rarely use it.

New to your channel, I'm trying to apply your formulas to my case but I'm having trouble using the C rate of my AGM Renogy 200A/H battery, it seems that it's 0 05C, is that correct? My setup is basic 400W solar with a 30A PWM charge controller and a 2000W inverter. The main use is to keep the fridge/freezer (300-400W) powered by the inverter while we tow the trailer, therefore without using the propane power. Do you see any issue with this installation? All comments and responses are welcome Cheers Phil

Your information doesn't speak of Peukert's Curve, or how parallel batteries can feed very large inverters. For example, a 12v 100Ah SLA (or AGM, though temperature sensitive) can only survive a 50% mfg. discharge rate...but if you place 10 into a parallel circuit, now you have the equivalent of only 10% of the Current demand...so a 5-year SLA deep cycle battery can now yield 100A currents...simply by (in this case, 10-units) dividing the current by 10...thus, 10 12v 100Ah batteries can power a 4000 Pure Sine Wave Inverter just as one 12v battery could power a 400 watt (small) inverter...with approximately 4-hours before 50% of it's charge is reached. I KNOW, as I built such an array with an advanced 4000watt PSW Inverter and 10 such batteries (to power a remote cabin)...it can take a 100A load for 4-hours safely without deterioration of the batteries...and the built-in 90-amp charger is within recommended charge amps...7-hours, give-or-take, from a small generator, can bring the battery array back to 100%...and that's if you pull 100-Amps on that inverter (something a small cabin would NEVER do). In reality, it will work for 24-hours and charge for 5 (charging is automatic)...why does this matter? Because 10 12v 100Ah deep cycle SLA batteries are IN ARRAY, and one failing does not mean all fail simultaneously! So, instead of replacing a $1500 LiFePO4 failure is ridiculous, when 'old school' SLA batteries, good ones, cost $150 each, and tend to fail individually over a few months of time! It just makes more sense! ALWAYS use Peukert's Law (calculators can be found on-line) to determine size vs demand and recharge, and build an appropriate sized array! Draw it out first, plan your recharge method (in my case, the PSW inverter also has an automatic 8-second transfer switch which starts the charging generator, too)...Amazon, my friend, Amazon!

Well explained, can you send these formulas?

what about 3000 watt inverter, 12volt 3x 300ah lifepo4 batteries and 800 w solar panels? how do I remedy?

200Ah LiFePo4 with 2500W Inverter, maximum need for Induction hob and Air Fryer is around 1500W, Microwave and Coffee maker uses less, so have used this combo successfully. Battery also has 200A BMS and cables are thick and 60cm long. So there is a way, but I admit that you are perfectly right!

Something you could talk about is using busbars like in your diagram. I bought some aluminum 1/8 x 3/4 stock and cut it down to 6" with two holes drilled in it for battery connections on my lead acid setup. Seemed to work good. I want to go with copper for my lithium hookup but no one talks about it and it seems everyone expects us to make interconnect cables. They also talk about using the same size for all cables and it seems to me interconnect battery cables for a 48 volt doesn't need to be as large as the wires going to the inverter. Large cables to the busbars where all the 48 volt batteries connect to. Very good video, thanks and I liked it.

Hello mate thanks for the great video you've gained a sub , this is my first time using solar. Im about to use a 12v inverter (3000w) with 2 12v 115ah lead acid batteries and a 30A solar controller. my concern is the amperage however do you think this can work ? Thankyou in advance

@steffenBoserup thanks for taking the time to write it out for us.

I use 12v lighting in every room and 2000w inverter for frig and freezer. Supply power is 800w=8 amps solar 200w=2amps wind feading 6 lead deep cycle 780ah batteries. Now given we dont run all the lights and kids dont leave frig door open lol i can run for months without needing charged from normal means . I set my system up for backup only (just incase) but i know im good to go . Off grid if need be

Very good explanation i have 5000 watts inverter how many batteries do i need and like wise solar panels and controller Gines

Awesome video, very well explained. I wonder, could you also make a video to compare lithium batteries to the more recent sodium versions?

Most modern inverters will draw from the solar power before the battery so when the sun is out the current can be much higher, but I agree with the load you have calculated for batteries.

The only time I’ve seen a situation where we had to select battery bank size based on the inverter is when using Simpliphi Li batteries. They can only discharge so many amps (it’s very low) and if the inverter was to run a large load the batteries wouldn’t be able to keep up and there would be serious issues. We had to have 3 of these 48V batteries, not for the capacity in Ah or Wh but because of the amp draw that could happen. Ridiculous

I have 2x 100AH Lithium RENOGY and a choice of a RENOGY 2000W or 3000W inverter. I think I’ll go with the 2000W for this year

Great info for longer-term setups. For short term, I use a 12v 100AH battery connected to a 3000 watt inverter. My total amp draw is about 12 amps per hour if I opt to run everything I need at the same time. This carry's the load for about 6 hours. I have a second battery that I charge on a propane generator while the other one is carrying the load, then switch them out. It takes about 1.5 hours to charge the battery, and I get about 14 hours of run-time on the generator for a 20# tank, which means I could get about 48 hours of power to the things I need. (TV/Internet/fridge/freezer/window AC unit/ portable heater/etc as each is needed) - I normally do not run everything 100% of the time, for example the window AC unit draws about 800 watts/5 amps by itself, so I tend to only run that intermittently, and hunker down in just one room with it running about 20 minutes per hour on average. - Same for a space heater if it is cold, though it has an even higher current draw)

Excellent

Brilliant Subscribed

Quick question wouldn't it be helpful to hook up a trickle charger to keep from running down the batteries

where does the 0.2c discharge rate come from? I have never seen that specified by a manufacturer. I have seen a 0.1c charge rate for lead-acid batteries, which makes charging them decidedly slower.

Hi this is from my house it'll be recharged for my truck my truck has an inverter and I'd be plugging in a 50 amp battery charger into my truck I'd like to buy two 200 amp lithium batteries for a total of 400 amps in a 3000 watt inverter to run my refrigerators at what consider a 2000 watt inverter. Pure sine . I will only be charging my refrigerator for power outages and basically I would be putting 5 amps back into the batteries as they're being discharged on the recharge side. What do you think

Just put you book in the cart. I have no knowledge of these systems and setups. I have a question that may be a tall order . Can I get a shopping list to power a 220 volt well pump ? To keep only my water flowing. The house is covered with a DP and added battery, now to get the water covered. Thank you.😊

I have a 12v 3500 w inverter what would you recommend for 24 v battery ( 12v/200ah) configuration , I also plan to use a 60a charge controller ! Would that be safe ?

Hi, can you please help in my project, I have a mppt controller AUTO 12,24 & 48V Wind 8 KW & Solar 5 KW and inverter 24V 6 KW - 12KW for this Project I think to use the LiFePO4 8x3.2V 310Ah. If I have mistakes please correct me.

Good info.

Per your comments @ 1:21 & @ 1:49, it would seem a Lead Acid Battery Pack should also be given that "25% Buffer", meaning a 400 Ah x 48V pack, or 4S4P Pack is really safer! But, most Lead Acid Batteries aren't rated at "0.2C" they are rated at a "20 Hour Discharge Rate". A 0.2C is actually a 5 Hour Discharge Rate (5 x 0.2 = 1.0). So a 20 Hour Rate, is 0.05C (20 x 0.05 = 1.00) You can find "Some" Lead Acid Batteries, rated on a 10 Hour Discharge Rate, as well, if you get the Higher Priced And more Exotic ones. However, this still doesn't count that Lead Acid Batteries shouldn't be discharged to "Dead" or "100%", but in normal use, should never be drawn down below "50%" of Rated Capacity! (If you want any meaningful Lifespan from them!) 😲

Thanks for the clear explanation. I have a 24v battery bank 2 x 230 ah (460x0.2=92) with a 2500 inverter (2500/24=104). My batteries degraded in a very short time span of 2 years. I am doing my best to learn from my mistakes. My first thought was that I discharged the batteries too much too often. The only guard for discharging too much is the inverter low voltage shutdown. But after your video i do not think that only the above was/is the case but i also sometimes discharged my batteries too fast. I am very curious what you think about this case. A company nearby claims that they can regenerate lead acid batteries in some cases. I will try that first, testing is free of charge. I’m also looking into lifep04 batteries for plan b.

Im a bit confused i have a 2500watt mig welder max 90amp. Thinking about fitting a 3000watt inverter in my garage what battery would i need to run the above thanks.

so I have 3x 105 AH battery bank. for 315 AH - planning a 2000 watt renogy invertor with 1/0 cable and a 250 AMP fuse. SOund good? we will almost never use appliances over 1k watts. we wanted the extra just in case. does this sound OK? 12v AGMS

I recently bought a 12V/200amp battery with a 200A BMS, and a renogy 3000W inverter with a 60a charge controller, to build a light system for camping in summer, would this be a good kit? any suggestions?

We have an alternator of 12v in a van vehicule, how can we install a system working at 24V or even 48V in order to be below 100A when requering high power, such as 3000 W and higher. I do not have clear how to charge the batteries using the van alternator. Many thanks

A question I used to ask electrical design students was if I start a 100kw generator with a 208/120v 3 ph 4W system, how many amps does it put out. In your case, if I have a 5000 w inverter and turn it on, how many amps at 120 volts is it putting out?

The 80A fuse you recommended, is that the AC fuse for the Inverrer? If yes, don’t you think that would be too much, especially, with a lead acid battery setup, considering that you would only be pulling and also charging at a current just around 20% of the battery capacity rating, per hour?

You are oversimplifying a bit. Its not how big your inverter is but more what load you will put on it. Also you should have larger inverter than you need for starting motors unless you buy a coil based inverter. I'm running a 24v 960ah LiFePO4 system using a 3000 watt inverter. My daytime load (highest) is about 1000W. After a couple of days of cloudy skies, my batteries are empty. I could really use a larger battery however I don't have the solar capacity to support it (3.7kw) especially during the winter months.

I recently installed a 12v battery 100ah tied w a 12v lead acid 50Ah in parallel. I have two 200 W panels on the roof for 400W total. Using a BougeRV controller rated 600 watts max solar and 40 amps. The only thing I’ll be running on that is the new Starlink Gen 3 satellite, which pulls approximately 85 to 100W. Along with that, a mini movie projector that pulls 80W. I should be good, right?

I use 3 x100 A.H. Lead Acid batteries for a 12 Volt 3000 Watt sine wave inverter..it runs an 800watt Inverter with ease.

I have 4 100ah 24v batteries and a 3000w inverter but, i cant seem to run off my battery bank for more than a few hours, im not sure what the issue is, im only pulling like 4-500 watts at most

Thank you for the clear video, I agree with its content but feel it slightly ignores a key dimension to this issue: it is mostly centred around the idea of running an inverter from a single battery only. In that case obviously higher voltages will fare better than lower voltages because they will require less current. But isn't it the case that you can supply the necessary input to the inverter within the relevant "C" constraints of your battery chemistry by adding more batteries in parallel. I am happily running a 3000W inverter using a set of six 24V (110AH) LiFePO4 batteries in my off grid cabin - at 3000W the total current is 125A but each battery is only discharging at a sixth of this because they share (equally, according to the bluetooth instrumentation they display) in the supply of that current. Did I miss something?

Great information. Much appreciated.

Great video, lots of interesting facts. Dont forget to verify the code in Your area, lots of nations do not allow non-electricians to work on more than 12 volt.!!! - DC can kill !!! To determine the number of batteries needed to support a 3000-watt inverter for at least one hour at full capacity, we'll need to calculate the total energy required and consider the discharge rate and capacity of the batteries. Calculate Energy Required: Power (W) = Voltage (V) × Current (A) For a 3000-watt inverter, assuming a 12-volt system (common for LiFePO4): Current (A) = Power (W) / Voltage (V) = 3000 W / 12 V = 250 A Capacity Needed: If you want it to run for 1 hour at full capacity: Capacity (Ah) = Current (A) × Time (hours) = 250 A × 1 hour = 250 Ah Number of Batteries: Considering the BMS's limit of 100 amps, and assuming you're using batteries of 100 Ah each, you'll need to connect them in parallel to distribute the load: Number of Batteries = Total Capacity Needed / Individual Battery Capacity Number of Batteries = 250 Ah / 100 Ah per battery = 2.5 Since you can't have a fraction of a battery, round up to ensure you have enough capacity: 3 batteries Wire Size: For wire sizing, you'll want to consider both the current and the length of the wire to minimize voltage drop and heat. Since the BMS can handle up to 100 amps, choose a wire gauge capable of handling at least 100 amps. Additionally, consider the length of the wire and refer to a wire gauge chart that provides the recommended wire size based on amps and distance. The American Wire Gauge (AWG) standards can guide you. A 100-amp load might require at least 4 AWG wire, but if the distance between the inverter and the batteries is significant, you might need a thicker wire (lower AWG number) to reduce resistance and voltage drop. Always consult local electrical codes and standards for proper wire sizing and safety measures. Additionally, remember to fuse or use circuit breakers appropriately to protect your system from overcurrent situations.

Sir price

Thank you I’ve got 280AH 3.2v batteries x 8 = 25.6v my inverter is 3000W 24v although I have a 5KVA Inverter but it’s 230v x 1 and the Chinese electrical grid ground also has a positive current Recommended within the inverter you can disconnect the power lead going to the negative ground cable but I haven’t seen that video how to do so to salvage my 5 kW inverter is in the American grid you could take the neutral and the L one each of 115 V this one phase 115v to my breaker box I have no 220v !

Any battery recommendations for off grid, for a 4000w inverter and 4000w solar panel ?

i agree im building a micro ecamper for my electric bike and im using 48 volts system made from 50 amp draw molie cells so it will power the bike and all the camper electrics and recharge off solar when camping

Thanks so much, I ordered the free diagrams. But one feedback: for some reason this video is blocked for saving to my solar power playlist for future replays and reference. Why have you blocked this option? Usually that option is only blocked for videos not suitable for children.

What capacity of lifepo4 battery is needed to power 250watts refrigerator

I just bought the power queen 12.8v 300AH battery and their 2000W inverter, do I need the 3000 W inverter? Or is 2K ok?

You get the same reduction in individual current draw if you connect the batteries in parallel. Typical 12V LiFePO4 battery is rated to 100amps continuous (as per your examples). a 3000W inverter running at 90% efficiency or better (typical) requires around 3300W of input. 3300W at 12V = 275Amps required (Watts = Amps x Volts). 12V 100Amp battery: 275Amps/100Amps = 2.75 - rounded up you will need at least 3 batteries. Therefore: Running 3 x 12V batteries in Parallel gives 12V 300amps continuous (with a power capacity of 3600W (12x300)). Provided batteries are of the same type (they should be), the current draw on each battery should be evenly distributed. at 3300 Watts or 275Amps, each battery will use around 92 amps. So, 3000W at 12V only requires 3 batteries (in Parallel). To achieve 3000W at 48 Volts requires a minimum of 4 batteries (in Series). It's all about sizing your system correctly. Trying to run a loaded 3000W inverter on a single 12V battery delivering 100Amps continuous, of course you're going to kill it prematurely. The key advantage to running in Series (to 24 or 48 Volts) is it keeps the overall Amps of the whole system lower, meaning you can use thinner wires and have lower resistance/less voltage drop (not a concern at distances of less than 6m). 48 Volt systems are typically used for homes with 5KW -12kW inverters (104Amps there @5kW without losses on only 4 batteries...) 12 Volt (and 24 Volt) systems are typically used for Caravans, Boats and RV's.

I did an experiment trying to make a system that was the cheapest possible that could run a 5000 BTU air conditioner. The single 12-volt 100 amp hour flooded lead acid battery it had lasted around 3 years. The cheap modified sine wave 1500 watt power inverter lasted almost that long. The system was also used to run a 500 watt heater in the winter. The goal was to use the power when it was available and not store it. The main drawback was that it would shut down on cloudy days often. Would be nice if there was an easy way of dialing in a cutoff voltage and having automatic restart with cheap inverters. Btw, I do only buy pure sine wave inverters now. They more than make up for the increased cost by how much longer they last, not to mention the increased efficiency,... I've also moved up to sealed lead acid batteries.😂 My favorites are the 6 volt 200 amp hour Mighty Max sealed lead acid batteries. If you don't run them down too far they're supposed to last 10 years, completely maintenance free. You have to use 2 of course for a 12 volt system. You can get a pair for around $439 delivered from eBay. Seems to be the best bang for the buck concerning batteries I can find. They'll even build up your muscles, weighing around 64 lb each.😊

So, to simplify, you recommend a lithium battery should be sized to have sufficient capacity (in Watt hrs) to run at the inverter's full power for 1 hour, or 5 hours for lead acid batteries.

Please, how can i get your book, I'm watching from Nigeria

What battery capacity is needed for running 250watts refrigerator

iam beginner on this, if i use 12v 100ah battery on 2000W inverter and only use like 400W is this ok or still kills battery?

You won't be hooking up that 12v 3000w inverter to a 48v system though. Wouldn't 12v 800ah be sufficient to run the 12v 3000w inverter without killing the batteries?

for a 3000w inverter can you use 2 x 12v 200 ah lithium batteries ? The calculation should be the same.

Please review a sodium battery...thanks

Which 3000w output inverter to buy so that I can connect it to a 12kWh 48V 230ah LifePo4 battery ( I charge it with panels via Victron 150/35), and I will be able to charge household appliances with it, such as a washing machine, dishwasher, oven, ...

I use deep cycle marine batteries and I have a way to get more.. you can't have too many batteries in parallel it just takes longer to charge

great video

The best feature of lithium batteries is how they deliver most of their current above 12.8 volts. Inverters love 13.3 volts

I had 4 x 170AH batteries in a parallel arrangement with a 3000w inverter. Putting the toaster on would trip it's cutoff and I'd need to reset. Might try a smaller inverter.

What about 12v?

How would I set up 2 24V DC batteries for a 3K W inverter ? Parallel?

I have 6 100W panels, 2000W inverter, Lithium Ion 300AH 12.8V, and 120A Charge controller, ....by. your calculation, 2000/12.8 = 156 A .... will the Amp load be too high? do I need to buy another 300 AH battery and wire it in a series in order to lower the amp load? if I hook it up as is will it explode

Please can 1200 watts on lights. small power tools. small air conditioners. small portable heater. television. small refrigerator. small microwave. small to medium-sized fans. If yes please which type of battery should i use 12v 100Ah

What could have gone wrong my two solar batteries are failing to hold charge, only lasts for 20 minutes. I am using two (2) Solar lead acid batteries: 12V 102AH x2 in parallel 150w x 2 connected in parallel and a PWM solar controller. I bought batteries in June 2021. Please help me

Hello I have a giant chest freezer that says 115v 60hz and 2.3 amps. It’s going to be in an ice cream truck. I also want to plug in a small POS system. Will 3000w inverter work?

I have 3 - 12v 300ah lifep4 batteries and a 12 v - 3000 w inverter.. will it harm my batteries since I can not reach 48v

Well, im confused. I have 600 watts of panels connected in parallel to a bus bar combiner. Each panel is fused at 10 amps. I have 5 100ah lithium iron phosphate batteries connected to a bus bar as well. Each battery is connected with a 100 amp in-line circuit breaker. I have a PowMr Pro 60 charge controller in this system. All of this feeds my 3500 watt pure sine inverter. My loads are never more than 2000 watts. It seems to run well. My system is 12 volt. How would you improve on this? Based on this video it seems im making mistakes.

Your formulas are correct... no doubt at all. The problem is, instead you did, the approach. It must be done deal with in terms of energy consumption in 24h. You're assuming a costant load of 3000VA... this is not a real case. To me the right figure should be starting at 0 o'clock with battery full charged.. recharge with solar panels the consumption will be regular as for familiar habit, with peak load, no load or minimum load. The important is total PV energy IN must be equal to the total consumption OUT. At the end of the day the battery is almost 100% recharged.