Parallel Inverters - Double the Power Hack! Part1

I make a crude attempt to hook these two inexpensive inverters together to power things neither one can on its own.
If you want a good quality 3000W inverter that is efficient, reliable, and actually powers 3000W loads unlike other inverters out there try the link below.
amzn.to/2JQKmbr
FTC Disclosure Statement:
As an Amazon Associate I earn from qualifying purchases. Some links may be affiliate links. I may get a commission if products are purchased using the links provided.
I cannot guarantee against unauthorized modifications of this information or improper use of this information. I assume no liability for property damage or injury incurred as a result of any of the information contained in this video. Be sure to read and follow all safety instructions for any equipment seen or implied in this video, and use safe practices when working with potentially dangerous equipment. No information contained in this video shall create any express or implied warranty or guarantee. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user.

[@edwinv83]

NO!!!! I've been loking for days how to do this on youtube and there are no videos, TRUST ME. THIS IS THE ONLUINE I FOUND! GOOD JOB SIR!

[@303nitzubishi4]

Everyone bashing the theory and saying it won't work are either skipping parts of the video or don't understand what he is saying when he is detailing the components and layout of the board. Anyone with basic electronic knowledge will understand that the theory here is solid and I'd bet it will work for this specific board design.

[@originalnightshade4582]

It works this isn't the only video that proves it!

[@samuelbaldwin3408]

I liked your video. It was very informative and I really appreciate the fact that you took the time to go over in detail the construction of the circuit board and gave a brief description of the functionality of the components in layman's terms so most people are able to understand and comprehend. So with that being said, thank you. Keep up the good work.

[@STEVEisAWAKE]

Very well done! Thank you for sharing some of your knowledge. Much appreciated...

[@jacknifedbl]

reminds me of your vid a year or so ago when u tied 2 UPS units together...great vids btw!!!

[@ghengiscrayon]

OMG. The wave forms! I am a few mins in and I am fearful for the result.

[@mikedesverknopf4681]

This is fascinating. I'm trying to run loads off a solar panel without a battery so I'm researching everything with the array to see where I can bypass it. I really appreciate your thoroughness and clarity of speech. Compassion for the people who make the products we use every day is important too because no one ever thinks about them. It's nice to see a channel less focused on its own success while still delivering the same amount of care, effort and humility you'd find in one that's paid for and fake. You're an awesome dude and you're really helping me out right now. Can't thank you enough for posting this.

[@knurlgnar24]

Glad you found this useful. On another note I would encourage you to look into other methods of using a solar panel to power non grid tie loads when not connected to a battery. Solar panels really need a battery or energy storage device in order to directly power any useful load. I would recommend looking into a charge controller set to 13.6V and connected to a small 4 cell LiFePO4 battery powering your inverter. The battery can be quite small but it needs to be there. The charge controller and 4 LiFePO4 cells adds some cost to your setup but it will operate as you intend and last a long time. Charge controllers can be had quite cheaply and if you purchase cells on aliexpress or the like you can find a 20ah LiFePO4 setup for a pretty reasonable price. This type of setup will only run when the sun is shining but will be able to continue running for short times when a cloud passes, a bird flies over, a leaf lands on your panel before blowing off, etc.

[@mikedesverknopf4681]

What about a bucking device to a charge controller and park in the middle of an open clearing? No issues with that on a clear sunny day right?

[@mikedesverknopf4681]

I simply can't afford any kind battery bank both at cost and space and weight right now. Free, sure. But nothing in life is free. It would cost me the same in batteries as it would for a complete solar array.

[@sequoiabentley4643]

You could possibly make a battery out of salt water for pretty cheap

[@Mattlawton-ft6ew]

​@@knurlgnar24where you beefed the solder up you could of put copper for better power 😁👍

[@markregan6133]

This is one of those hacks that gives hacks a great reputation. I thank you. BUT please add a caption warning about never making a double ended mains lead for any purpose they are lethal especially in Europe with 220v to 240V.

[@80amnesia]

thumbs up for trying a daring experiment

[@Coolkeys2009]

I promised I wouldn't rant but I have 4 bits of broken IT equipment and 3 were more or less faulty out the box. Whenever you pay good hard earned money for a product and receive a poorly made piece of cr*p. You have a contract between the retailer responsible for selling you the cr*p and the manufacturer that produced the crap. Those are the only people that should be blamed the retailer for selling stuff they new wasn't fit for purpose and the manufacture for not maintaining quality control or hiring/keeping good/skilled staff, giving proper staff training, motivating staff etc. If a business puts profits ahead of customer satisfaction you as a consumer should not be happy. With all the corporate advertising/news media etc. We often forget that we have a right to get what we paid for and often love/respect business's we should actually be angry with. Anyway good video, glad to see you back.

[@virtualbox9556]

So quick question, if you just plug a male connector into each outlet and then have the negative and positive output from both inverters meet up with the use of some diodes or rectifier to allow both 410W to be combined into one female outlet?

[@danwells7691]

Coolkeys2009 how would you get satisfaction. from the chinese

[@DobleWhiteAndStabley]

Damn your hands are HUGE! It made that battery look absolutely miniscule.

[@mickgatz214]

4/5ths thru your video. Interesting! i myself am dabbling with inverters as such. Keep up the good work. Cheers Mick

[@skipwilson5086]

Mick, what have you done to your inverter? I'm trying to increase the Amps out of mine.

[@jeremiahputnam3893]

I like the idea. They should have pairing ports like the new inverter generators do. Then you could buy smaller ones and link them up later over time and money.

[@goofykl9]

I was looking for this, now I have a way to build a frankenverter

[@MrIsuko]

Thank you so much .You saved me so much time ,I was thinking of this idea for long time ,thank you.

[@chevytruckman34]

Mad solder skills!!

[@garycrumrine9538]

I agree wit William. Buy 1 bigger inverter instead of mucking around with connecting two.

[@ghostunix731]

I recommend a ups invertor and solar panel. Sure it might be expensive to have solar ups but hospital bills might be expensive but burning down. Your home is expensive to

[@daniellange4772]

Stacking inverters is easy with most wholehome inverters, you usually link em with a cable to sync the waveform.

[@tomyhadera91]

at first I was like what did this guy smoke and then he smart . thanks

[@jeremyhenderson163]

Thanks for sharing,great ( thorough ) video. An chance you could tell me why my (new,out of box) inverter "fault" light displays and anything plugged in comes on and then off (continuously,until unplugged). I thought maybe they weren't getting enough current from my batteries,but that seemed too obvious and didn't want to short they.

[@joepah51]

Excellent video.. well spoken.

[@realflow100]

Ooooooookay that sounds like it would work perfectly..... I noticed they can both be used seperately as in 410W to each one seperately.. OR 820W in only one or the other. That sounds like a very interesting idea and the idea sounds like it would actually work.

[@gelumiro1160]

sei un GRANDE grazie

[@RiaRadioFMHD773]

In Japan the AC mains is 100VAC (60Hz South Japan, 50Hz North). I use 115VDC much. Any high speed switching power supply should accept DC as it goes through a bridge rectifier anyway. Of course this will not go through any transformer, but I do use my laptop & curly fluorescent lights on it. Any resistive load like soldering irons or incandescent lamps will not see any difference. NOTE: being off grid rules.

[@dashtesla6431]

That's a good thing, the best off grid system would be DC/AC hybrid, i would go for 20x12V batteries 240VDC (arcs level photonicinduction) and an industrial 240VDC inverter so it runs induction motors etc, if you're running your own custom system doesn't matter where you are you can use any voltage you want ac dc 120 240 etc

[@freedom8480]

" full bridge rectifier" rulez 🤣🤣 Okay, different channel.

[@bjornahh87]

I was wondering what if you put some highvoltage capasitors to the outlet too so you have a bigger reservoir to get power from, did that to mine 600w 12v inverter and soldered an ac capacitor over the socket in the back of where you plug the cord in, and now I can use a 500w 230v oven on the inverter when it gets wery cold outside, and if I'm roadtripping I'ts so nice with some extra heat too...

[@lokomarevenant3107]

nice thanks bro i love your videos

[@beingsentient]

I enjoyed your video. In the beginning you explained that the plan is to eliminate one of the output bridge circuits, thinking that you only need one to handle the double load. Yet, you didn't show us that you did that. Finally, why didn't you simply lay down a copper wire on the input bus and solder that?

[@FroilanWINDSOLAR]

Interesting and genius! plus comment about social issues!

[@Mike_Greene]

"A fool starts too early" . . . lol 1:33

[@voglerlake]

what about taking an extension cord mail plug in double up on that Korea have to mail plugs not looping back to each inverter but is supplying the main load line of the extension cord?

[@PatricksDIY]

12:31 That is a voltage limiter, if the size of that copper is increased it allows more power to go through since it lowers the resistance, but could also burn up the board and render the unit useless with all the extra voltage. I have seen people by pass (bridge) that

[@lancelot1953]

Hi Knurlgnar24, great videos, very informative and well documented. The only thing I would recommend is to warn viewers BEFORE you demonstrate the wrong way of doing something or how "not-to-do" some procedure. The reason being that sadly enough, some less inquisitive viewers or viewers that are "in a hurry" do not listen to the entire video and blindly follow your initial procedure. You are right though, some people will connect both of them as you showed in the beginning. Ciao, L

[@FieryPotKitchen]

yery true. ...that wrong way could have been eliminated

[@jameswilsin5348]

I find cold solder joints in all mine i just redo them and they are good

[@kokopelli314]

I use braided copper solder wick to beef up connections.

[@EngDrewman]

Is it possible to convert an old generator to an inverter generator by running it's output through a bridge rectifier and connecting it to the output stage of the inverter as shown here, maybe with a small 12v transformer to power the inverter circuitry?

[@allinthefamiliy3122]

Hi Knurlgnar, i have enjoyed your videos about inverter reviews. You have a good voice, good explanation and good tests. I have a question, based on your experience what Ebay inverter with a good price performance ration do advice me to buy. Thanks.

[@kellycarver2500]

I bought a Schumacher 2000 and was wondering how many solar panels and batteries I should get to use with it. I plan on sometimes running some power equipment, but usually just lights, a mini fridge, and maybe an inline water heater off and on. Any input would help. Thanx!

[@00708046]

I can't make out the alligator connections . Are you just making a parallel connection from the + leads and the - leads ?

[@jsmith6259]

Yeah I totally agree about you saying about make you something correct we have the same do something right or don't do it

[@AlexandruVatamanu]

I hoped you would connect one control signal to both inverters in order to have both output bridges working in synch. Each inverter would still output nominal so they would need to parallel the outputs somehow. Like they do with gasoline inverter-generators.

[@knurlgnar24]

It's been a while since I released an inverter video and it's past time I do so again. This is a project I worked on about 6 months ago.

[@danyala.1659]

Now I just hope this will work with 5 inverters!

[@danyala.1659]

Actually, I cant do this with 5 inverters... they will fry each other up.

[@danyala.1659]

Can you use this instead? www.smarthome.com/a-neutronics-mlsl-11510-10-outlet-19-rack-mount-power-strip.html

[@knurlgnar24]

Danyal Ahmad Looks like it would just connect them each together with a switch to turn each one on and off. They'd still go 'poof' when switched on if not synchronized!

[@ash2870]

knurlgnar24 Sir can we make a pure sine wave inverter at home? Is it possible or too complicated?

[@chronos131]

I had one of those. It caught on fire.

[@SsDiBoi]

I thought sum1 had 2 be desperate to figure chit like this out awsum vid🍁🌚

[@rileyham9058]

This is very informative and makes me curious if you could run them in series to get 220v power because i cannot find a 220v inverter(i understand a vehicles electrical would have issues but i would be upgrading mine)

[@knurlgnar24]

This could be done if a person synchronized the inverters and also connected them to separate batteries. (they reference battery ground) From a practical perspective it is always better to simply purchase a larger inverter. This was a fun experiment however!

[@DavidTomko4u]

does it matter which one you plug the socket in if you want to plug one higher watts appliance

[@retrodigi375]

Will current distributed betwwen them? Or will they each take the same current as if it were a lone convertor, i desire to pull a lot of amps but a single convertor just isnt rated for the full desired current

[@colinsmith6340]

J1 is the current shunt. Look at the other side of the board, a jumper is not needed there. Its also high in the air too. J1 is your current shunt.

[@TheSign2020]

If you don't mind explaining where do you wanted to plug the inverters and why would you need it? And where are they usually used?

[@mangreat71]

My Question is do it has a built in fuse like a 5 amp or a 10 amp or even a 15 amp ? Cause what i was trying to do is make a home made jump starter or power pack for charging appliances but i think i need a fuse like a 10-20 amp car fuse with the top post car battery ???And which 1 of these inverters has a built in fuse like a 5-20 amp fuse ???

[@sephangelo4603]

This is good because I have yet to see one inverter for sale capable of handing like 30 batteries.

[@TonyLing]

I think that crude link with high temperature sleeving on the input may be a current shunt

[@wwsummers]

i recommend just using a larger invertor. use the smaller ones for portable power or something else.

[@noonrideevening1804]

or you may use head and you don't have to buy. And if bigger power need is short-term, its trowing money away.

[@jameswilsin5348]

Use a 3 way cord two male ends and one female ends conect your power switches to one switch then they kick on at same time but use two of the same brand and or same size you do it same way thst you would do 2 60kw generaters and have a breaker in one side the cable turn both on let tge one stableize the make sure the breaker is of turn on other inverter let it power up then flip breaker it will eather work or it will blow tge breaker

[@ghengiscrayon]

Ok, so by parallel stacking at the bridge before the high voltage dc hits the output Fets, you avoid a catastrophic failure via non synch waves (don't cross the streams Egon) BUT if the output section performed cool, why not just stack the Fets 'n' caps in the input section and push the Output section to the max in one, smaller box?

[@abyssunderground]

Presumably the transformer wouldn't cope? And I doubt the existing traces would be good enough for double the current either. They'd probably need some modifications.

[@davidhopkins9021]

U could buy a 1000w inverter just a thought

[@johnbrown-uv6kn]

would a apc es750 ups accepet power from a modified sine inverter ?

[@liljasere]

I miss old KZbin

[@knurlgnar24]

We all do, and not because of anything related to me or you.

[@liljasere]

@@knurlgnar24 Don’t sell yourself short you are one of the greats

[@johnconrad5487]

I know this is an old video. did you finally find the current sense 'resistor'? it is there in front of you. Perhaps now that 4 years have passed you either found it or figured it out. Also why did they rectify the output of the transformer and then add another stage? is this a real sinewave inverter or is it a modified square wave inverter?

[@tonygernstl3859]

What was the whole actual purpose of soldering the 2 individual wires to both inverters? I want to attempt to parallel connect 3 cheap chinese inverters together and want to know If I have to do exactly what you did.

[@pascal92542]

would this still work if each inverter were fed with different voltage battery banks? (likely in different charge states)

[@mwilliamshs]

"you end up with a pile of smoke" love it! if you were shopping for a 1500w pure sine inverter to use daily for 3 years, what's the least you'd expect to spend?

[@DMAN22yeah]

samlex go power or thor they are all the same thing and they are good quality

[@KillaBitz]

i've had expensive inverters pop in under a month and right now i'm rocking the cheapest one on ebay (the first one died but i got a replacement and the fan circuit didn't work on that so a just wired to 12v) I had 7 inverters last year. This one has been going every time the sun shines for 9 months but i cant recommend it. Inverter recommendation is difficult especially when you put in a time requirement. do you live in a warm climate or a humid climate or both? are you trying to power inductive loads? are you expecting to pull 1500w from it all day (running at %100 will stress it) are you going to power it from clean power even? (it's no good trying to pull so much power from 1 small battery it drops to 9v if the inverter isnt designed to run that kind of current) You haven't given any information at all

[@carlosreyes6448]

How would you connect them, in series for 240v

[@Max-kn9yi]

I would like to combine 2 jupiter 2000 watt inverters from harbor freight. Not sure I can do all this, but they are on sale now

[@dominicsanthuff]

So to get more watts outta a inverter I wanna upgrade I just gotta upgrade the capacitors and maybe the output

[@bartw5908]

Great video, well done, I have a Spark 4000w pure sine wave, not used a lot, but the last time I used it the wattage meter ramps up and it goes into overload and shuts down with no load plugged into it? Do you have a video off what this could be?

[@knurlgnar24]

I'd recommend ohming out the diodes and output FETs. Sounds like a shorted FET on the output stage. If so that can usually be fixed by replacing just the FET or FET pair that shorted. You don't need to replace all of them. The tricky part is figuring out what to purchase to replace it with. Try to match up the capacitances in the datasheet and be sure the resistance is similar and the voltage rating is at least as high.

[@phahymn]

i was just thinking, what if someone actually paused the video from time to time and follow these instructions as they demonstrate.....untill 1:30 hmmmmmmmmmmmmmmmm lol

[@pattoe1973]

you make me sóóóó happy ,i feel education level rising inmediatly ,and im adicted to it

[@codyaustin3728]

i have that exat same battery but two of them those are 12v alarm back up batterys

[@robertpolito6139]

You can add 10 AWG copper wire to the bus bars by solding on the bus bars.

[@benleech3443]

How do I modify my inverter to go below 12 volts

[@ohsofficer]

Please show a test result for the output, also, one inv has 20a fuses and the other 25a, should be the same

[@poseypapusdiazfamily4630]

To add more surge power just add high voltage capacitor in parallel with high voltage dc one.

[@josepeixoto3384]

Very good idea,thank you.

[@chriscollins9377]

add some copper wire to the solder to increase amps.

[@jameswilsin5348]

Or just use a 3 waycable and a breaker between tge 2 and start primary tgen start secondary flip breaker try that dont need to take them apart or you can do the smart way andjust by a larger inverter

[@douglaswindsor120]

To get more capacity through that solder on the board you should have added a piece of copper wire and imbedded it in the solder

[@biatchhh2334]

do you have a video that shows how to hook the inverter into your home circuit panel?

[@knurlgnar24]

kzbin.info/www/bejne/r5rco5xmgMdsjdk The approach shown in the above video is simple and low cost, but is for emergency purposes only and I go over the many dangers of this approach.

[@badactor3440]

Will this work with higher wattage inverters?

[@shooyooyoon9007]

so soldering two inputs and two outputs ?

[@asifiqbal4590]

Hi I am big fan of your work...need some help to make parallel inverter....

[@meowsoftware7258]

Can I use two 4000w inverter parallel ?, is that risky ?, one inverter capacity is 4000w continuous and 8000w peak, so I have 8000w continuous and 16000w peak

[@douglloyd9662]

Don’t let the magic smoke out.

[@bikiniluvnguy1]

I was hoping it would be simple like hooking cables up to the backs in a certain way, this is way over my head.

[@omaralvarado1080]

This is what I wanted to do but taking out the outlets and connecting them into one outlet

[@vortextremesg3874]

I have some 20 amp automotive circuit breakers. They reset automatically I believe using a bimetalic strip. I put them in my power Inverter. Might be a better idea to put manual reset breaker, That should remove any dumbassery from consumer's.

[@johnrobertelardo9787]

Rookie question: Can I connect the inverters in series to, say, I have four piece 12v inverter connected into series to create 48v input?

[@knurlgnar24]

Unfortunately no, you would need a 48v inverter. They will not 'share' the voltage evenly.

[@Disillusioned_one]

What would happen if you have a pure sine wave inverter running. Then connected a grid tied inverter to it, would the grid tied inverter match the first inverters sine phase and frequency and. Add its output to the first.

[@knurlgnar24]

That's a good question. The end result would depend on the design of both the grid-tie and stand-alone inverters used.

[@satibel]

+roy douce I think It all depends on how your first inverter handles being fed back. The grid tied inverter should adapt to the main inverter.

[@kevin9c1]

You could have added a short wire on that node you added solder to, assuming it would fit back in the case.

[@josepeixoto3384]

of course...

[@mikeriverajr4447]

can you split phase these?

[@SteveWrightNZ]

Parallel the AC output of those units at your peril...... Must have AC sync or it will burn..

[@arkangel8709]

Hey" just wanted to say: thanks for all the info.!! I like your No Bull way of saying How to do this or that,!!!

[@hydroalternation]

What happens to phase when not in sync

[@charleshoward9983]

man that was cool.Imagine that.

[@angrytiger9346]

Could you use the same process that you did with these 400 watt inverters for your samlex 3000 watt inverter if you had 2 or would it be a little different if so how I would like to at some point do it for a cabin or house

[@knurlgnar24]

Timothy Moulton I actually do have two 3000W samlex inverters and I've considered just such an arrangement. Unfortunately they're expensive and I don't want to blow them up. :( Pure sine inverters are much more difficult to parallel since the FETs switch at high frequencies to generate the sine waves. The idea I had was to power two different phases of a distribution transformer with them, and then use the other side of the Xformer to get your power at the proper voltage. You would then only need to sync the two and ensure they both shut down and start up at exactly the same time rather than mess with everything else. Still, it's too much of a kludge for me for an inverter that is already very nice out of the box.

[@triumphmanful]

You said, you are doing this for first time, but soundsd like you are a very well trained and qualified electrical engineer . The things you are suggesting are not for ametures like me. I would be afraid to destroy my inverters. Money lost ! FYI

[@larryreagan6936]

Just asking a question, would it be better to use a step up/down transformer using each 110v leg as input and step down the 220v from both inverters back to 110v on the transformer output at the higher rate? again "just asking"

[@gravelydon7072]

How are you going to sync the two? The output of the inverters has to be synced to work on a X1/X2 and Y1/Y2 input of a transformer to get 110 VAC out at double the current on the output side of the transformer. If they are out of sync, you could see anywhere from 0 to 240 VAC on the output until the inverters tripped.

[@EnduroSkills]

What about putting the two power switches of the inverters in parallel? Curious how the two waveforms would overlay on an oscilloscope

[@knurlgnar24]

That would be the better way to do this but it requires more work. You would need to remove the FET drive from one inverter and parallel the FET gates between the two. You would also need to ensure both boost circuits boost to nearly exactly the same voltage. I actually planned to do this but decided it wasn't worth it.

[@josepeixoto3384]

@@knurlgnar24 Thanks for clearing this up; i have 2 inverters, same exact model, cheap from China,5000 / 2250 W , 24 volts, and i would like to parallel them to get ~~4000 watts; i repair PCs,laptops TVs etc (but NOT at component level, i´m not that good); Do you think it can be done? parallel the FET gates, with a cable between them, and check the 220 V outputs? if the FET gates are in parallel,you think the 2 sinewaves will coincide all the time,no drift? Thanks

[@bronprat5916]

instead of adding more solder. why dont you add wire as the race way

[@RogueOntheRoad]

As a beef it up bus point instead of just adding a bunch of solder also solder a piece of large wire to the trace. The copper wire increases conductivity as you said solder alone doesn't much. Use stranded wire for even better conductivity.

[@manolisgledsodakis873]

Use the braided copper screen from a good-quality coaxial cable.

[@court2379]

How is stranded any better than solid? You either have the cross section area or you don't.

[@RogueOntheRoad]

Actually what I was thinking was to use the solder wicking braided copper. Once it is soaked with solder it doesn't matter if it is stranded or solid the standard wire should support the overall strength of the conductor path.

[@cj691]

I feel like J1 is your current shunt.

[@matteuklol]

This is probably a really dumb question but why not just connect the negative and positive together on the input and connect to the battery? What is being achieved by soldering them together by the capacitor?

[@knurlgnar24]

The output AC waveforms are not sync'd nor balanced so they can't be connected together directly.

[@jacovandeventer1939]

You dear Sir are a genius, i was wondering, is there a way to share the output through both sets of output FETs

[@knurlgnar24]

You have to tie together both the output of the boost stage like I did here, and also the gate control circuitry for the bridges. (disabling one of the controls so that they don't interfere) I was afraid connecting them with long wires would lead to problems so I did not do that.

[@jacovandeventer1939]

@@knurlgnar24 Awesome, thanks for the reply. I'm from South Africa where our power stations have been neglected to the point where we can't generate enough electricity to supply the entire country so they have implemented "load shedding" were they periodically turn of electricity to towns across the country and for some reason it is cheaper to buy 2 or 3 smaller inverters than 1 high wattage inverter but im afraid that the FET's on say 2 x 1KW inverter won't handle the possible 2KW current draw hence my question about connecting the FET's