DIY Split Phase Battery Backup for Home - Step by Step

[@ProjectsWithDave]

Current Connected Website Affiliate Link: www.currentconnected.com/?ref=pwd Downloadable circuit diagram and all project details on my website: projectswithdave.com/120-240v-victron-home-backup Single Phase Victron/SOK Home Backup starter install video: kzbin.info/www/bejne/eKuwcopuoLxjebc

[@jonathan-657]

Wow, they have the Solark 15k for $1.7k less than what I paid.

[@DoDoBedStory]

does 2 inverters with 3 batteries workable?

[@ProjectsWithDave]

Yes, you could do this setup with just 3 batteries. You would just have less storage capacity.

[@ProjectsWithDave]

Sorry, wish you had seen that in time. Current Connected has good prices, quality products and great service.

[@artemas33]

Just bought 12 EG4LLs for that very reason

[@AdamDeLayDIY]

Thanks for sharing the update! At 49:22, you mentioned that the shunt loses its SOC if it loses power. Victron actually updated the shunt to give you the option of what you want it to do if power is lost. That’s the “Battery SOC on reset” option, which right now is “keep SOC”. I was so happy when they added that in!

[@ProjectsWithDave]

Thanks for commenting on that. Yes, that new feature is great. It works as long as nothing changes to affect the stage of charge after it looses connection. I didn't realize the update until I was done editing that section, but I did change the settings to "keep SOC" in the video. Thanks!

[@AdamDeLayDIY]

@@ARLGD Never heard of it before.

[@AdamDeLayDIY]

@@CherokezPittman never heard of it

[@chadmarkley]

Dude, I LOVE your channel. I installed my own 15K sol-ark + 37 400W panels (with the help of GoGreen Solar for plans and such) and I give you and Will Prowse a ton of credit for giving me the confidence to do it and not hire it out

[@johnfitbyfaithnet]

Impressive

[@chucktrotter9699]

6.24.23 Dave, this is an excellent install video. Thank you for taking the time to make it. I am currently building my own system. I am using 1 EG4 battery and I also have the EG4 buss bar battery cabinet. I also have the Victron Smart Shut. As time goes on will add more batteries. The batteries cost the most. Thanks again

[@ProjectsWithDave]

Thanks! I'm glad it was helpful. It seemed like it took forever to film and edit.

[@lyfandeth]

The US Navy used to have a web site up about working with power. There were also photos of a sailor who forgot to take off his wedding ring, which caused a crowbar short on a single 12vdc automotive type battery. They can and do provide over 3000 amps in a crowbar short, which resulted in the immediate traumatic amputation of his ring finger. That's one reason silicone wedding bands are now common. I don't wear rings, but I did manage to weld the rotating bezel on my metal watch. Twelve volts can really surprise you.

[@0my]

Just another reason to avoid marriage

[@kingcrimson234]

Yup, it's not about the volts, it's about the amps.

[@icedout2322]

yea I did this tightening up a positive with both batteries connected to a starter on a M38A-1. I ripped that band off so quick I didnt even notice it took most of the skin under and around the band with it.

[@OldCurmudgeon3DP]

I worked in substations for 20yrs. Never wore a metallic ring, ever. Silicone for the win. It's non-conductive and can't rip your ringer off if it gets snagged. The idea of a gold band conducting across terminals connected to a 200Ahr, 125VDC substation battery was less than appealing.

[@doingstufforatleasttrying4843]

So true, I was coming back from a wedding and saw someone stuck on the side of the road with her hood open. She ran out of gas and walked a mile for some gas and when she came back her hazard lights killed the battery. I gave her a jump and my bracelet touched the fender when I took the positive off. It burned completely off my arm and left a nice scar to remind me. That’s what I get for helping 😂. I did car stereos and alarms for 30 years and never a problem.

[@user-fy7ru4ii1i]

My first battery was a MASTER CRAFT. It worked well for testing out this solar stuff, for the first time. I was given an INTERSTATE battery from a mechanic friend, who wasn't using it, it was a welcome addition to the 'customized battery bank'. I then got myself a PRO POINT battery (which was twice the size of my master craft battery). They're connected in parallel. I've got a humble 2000watt sine inverter and 11x 230 watt panels on the roof. It's a 'starter'/beginner set up...but I've learned a lot.

[@ProjectsWithDave]

It's good to set up a small low cost system. You get some emergency power and a learning opportunity.

[@FastEddy396]

A microwave is like an on-demand oven, which it is. It's off almost always. Your videos are amazing every single time. As an electrical engineer, your work is brilliant and best of all, helpful. Best-

[@ProjectsWithDave]

Thanks for the encouragement, but I'm actually a mechanical engineer not electrical. Most of my electrical knowledge is from research and projects like building my house and solar projects.

[@FastEddy396]

@@ProjectsWithDave I should have said "speaking as an EE..." I knew you are an ME from your posts. That's part of why I'm so impressed with your work as many people are nervous with electrical things. Glad that no one got injured when you had to redo those casters! This project is exactly what we are planning as well, right after I plumb backup water tanks into the house with a DC pump. Best-

[@ProjectsWithDave]

Thanks. I'm glad it's been helpful. I know I don't get everything right, but I always find it helpful to see what others are doing even if I don't adopt everything they do. The nice thing is, I can always count on someone to correct me in the comments.. : )

[@tepidtuna7450]

I get around the wheel problem by screwing my shelves and benches to a thick sheet of MDF (or plywood) and bolting the wheels to the MDF. This might work here, however I use the same wheels you have chosen, but with the 4-bolt mounting swivel. Like you I studied Mech Eng and I still find out the hard way too. Love this vid. ☺

[@Sylvan_dB]

are you familiar with shop "mobile base" to move a tool around the shop? They have a pedal and lever assembly to push the wheels down and lift the tool, or let the base and tool rest directly on the ground for use. A mobile base is the way you want to add wheels to a server rack. Not by putting wheels directly under the posts of the rack. The posts need to be tied together with more structural strength and is designed to be mounted to a cohesive, uniform surface to provide that tie.

[@picobyte]

I'm always amazed at that 110/220V split phase. Here in the Netherlands we get 400V three phase and that reduces lots of ecpensive copper wiring.

[@ProjectsWithDave]

Yes, It's interesting how countries get "stuck" with legacy construction that ends up increasing costs for all the future generations.

[@donaldreynolds4003]

Not sure what SCC you have, but the Victron Smart Solar Charge controllers are awesome. I just converted over from a MPP Solar LV2424 24 volt system to a Victron Multiplus II 2400 /70 A system with 10kwh of SOK 206AH Marine batteries. The idle consumption of the MPP solar unit was 40 watts an hour! My new Victron Multiplus-II uses about 13 watts. It is like having an extra battery. I use mine to run my freezers in my garage and the refrigerator as well as a sump pump. I have two more 206 AH SOK batteries that I will use with either the old MPP solar unit or with the 12 volt Victron Phoenix inverter. I live along the coast in NC, and after Hurricane Florence, I decided to invest in a back up system. Your setup is awesome, but I have back issues, so I stayed away from the server rack batteries. Anyways, great video content and take care.

[@ProjectsWithDave]

Thanks for giving some real world feedback on your system. My 48V MultiPlus II only uses 9W per unit at idle. It's amazing!

[@bruceeverett5372]

Great video Dave, thank you for all that you put into this one. I was on the fence between the new small Sol-Ark 5k1p, and Victron....this tutorial plus the drop of the new Multiplus II 5k sealed the deal for me. Victron equipment is so nice, efficient, reliable and most of all -- supported. It's definitely pricey but "Buy once--cry once"

[@ProjectsWithDave]

Victron is more expensive, but I've never had any issues with setup or performance.

[@barrymclaughlin794]

Don't forget to mention that these are Low Frequency inverters and for some clients that is a critical need.@@ProjectsWithDave

[@racingtogreen2023]

Could not have gotten through my recent parallel install without this. Big Thanks! I have run into the different length A/C conductors issue, it appears. My system is very compact, (mobile EV charging system) with one conductor (10awg) set, being around 24 inches, the other, 12 inches. This is resulting in an overload alarm on L1, and ultimately, the inverters not starting up. Trying 4ft equal length conductors today.

[@ProjectsWithDave]

I'm glad it was helpful. The AC side conductors don't have to be the same length, just DC. The AC side will always be unbalanced so length plays a very small part in that. When do you get an overload alarm? Are you sure you don't just have too many of your loads on one phase?

[@kingcrimson234]

Great setup! There are also single units out there that'll do split phase, I went with a SunGoldPower 10 kW box and 5 of their rack batteries. I used the same SOK battery rack you have but with SGP's batteries and a total of 25.6 kWh capacity. It runs our house for a day and a half from a full charge. I'm very impressed.

[@ProjectsWithDave]

I have a SunGoldPower split phase inverter, It has been running for about a year now with no issues, but setup is a pain. You can see it in this video: kzbin.info/www/bejne/f4vNeoaneryaorc

[@Vikingza]

Hi, I would have rather suggested that you use a Quattro-II 2x 120V and a Cerbo GX. By using a Quattro you would not need a transfer switch and the Quattro would perform that function and with a Cerbo GX you can monitor your Charge / Inverters remotely. You could also connect your generator to the Cerbo GX and when your batteries get low the Cerbo GX could start your generator for you automatically and you would be able to monitor the fuel level then the tank of your generator.

[@InssiAjaton]

About the wheels -- sort of reminds me of how welding gas bottles have to be secured somehow. Basically it is with a chain to wall, or short term into the transportation cart. In your case, probably you could use for example angle iron bolted to the wall and two shorter chains from the backside verticals. Would look nicer than a single chain all the way around the front.

[@barrymclaughlin794]

I was considering a SolArk 2P but two Victrons with the low frequency capability are making my deciscion harder, great video, very helpful, thanks.

[@dupre7416]

I've heard you mention your well pump in a few videos. I'm wondering if you ever looked at solar well pumps like the ones from Rural Power (RPS). I'm using their 24v solar well pump off of just two 100w panels. I ran exclusively off solar (no batteries) for 2 years. Just recently, I added 2 12v 100ah lithium batteries in series which means I can now run the pump at night. It was about $2,700 including the batteries. That included everything except the metal pipe that the holds the solar panels.

[@FMuscleZ28]

8:44 Well, no one expects an engineer to be smart... I've had to teach one, our supplier of control units and modules for various systems, what a short circuit was........... I do enjoy your videos Dave, very informative, I've been thinking of going solar for some time, and it could start within the next three years. Hopefully.

[@ProjectsWithDave]

Hopefully you can learn from my mistakes... : )

[@FuncleChuck]

I'm glad you showed how bad the original idea for wheels is - but I wouldn't want to be near that thing if it's not bolted to the ground! That's a very scary thing to put on wheels.

[@ProjectsWithDave]

Yes, I don't recommend it. I need to be able to move it for all the testing I do.

[@brucebugbee6604]

Excellent presentation. I did something very similar at my house with a 22 kW battery bank and two Multipluses. I can only get about a days worth of backup without charging the battery. I have 3 kW of panels so I still need to use the grid for about half of my whole house load but it sure is nice to have instant backup during an outage that allows flexibility as to when I want to run my generator.

[@ProjectsWithDave]

Thanks! I have to say, the automatic backup for outages without having to dig out the generator is great!

[@ChrisW-nq5vp]

At a bare minimum you want to be using Class-T fuses as your main bank protection for an LIFPO4 bank. This bank can easily throw 20,000A or more of current into a dead short and can damage and literally blow windows out of Mega fuses.

[@jensschroder8214]

In Europe there is the 230/400V electricity system. The small inverters are connected between neutral and phase 230 volts. In the three phase system with 400 volts in Y configuration with neutral. The instructions also show that the same inverter can be connected to 120/240 volt split phase. So on phase to phase 240 volts, but not with neutral. With three-phase then in delta configuration without neutral.

[@danchesney631]

You'll need a plate on the bottom of the rack. And the castors need to have steel wheels, the soft wheels will flat-spot over time.

[@johnfitbyfaithnet]

Good tips

[@M35a2guy]

Dave really enjoy your videos. I did something very similar but with the addition of the Victron autotransformer. At first I just didn’t know how balanced the loads were and if it would top out one side of my split phase set up before using the equal amount of power from the other. Turns out in use it as you would usually mode I have less than 1000 watts imbalance. The auto transformer absorbs the imbalance with no problem allowing me to draw almost identical power from both victron multis 3k. It’s fun to watch on the Cerbo GX

[@mflo1970]

Victron no solo produce una señal estable aunque limitada en potencia para proteger su ingeniería, también te permite conectar generadores con señal no muy buena y permite un gran abanico de posibilidades de conexión y control enhorabuena por tu elección y tu canal

[@jotunofficial]

Dave, just wanted to say your videos are awesome, and super helpful for me doing research on setups like this. One question: will you eventually run conduit for the DC cables? I can understand why you would want some flexibility while you're testing things out, but wanted to know if you planned on running everything in conduit eventually. Thanks again!

[@trollking202]

Conduit lowers the wire rating

[@USA-GreedyMenOfNoIntegrity]

Why would you need conduit at 52-58V?

[@aaron840]

at @50:40 mark that one wago issnt fully locked down. you may want to double check them all

[@MS-ie1gs]

Crazy to think that the Ford Lightning accomplishes this, but with a battery 4x to 5x the size. It can power 220v loads, and the cost of a used one with less than 10k miles is $60K. I priced it out, and this could be a cheaper option, plus it can function as a primary vehicle.

[@FuncleChuck]

It’s not quite that simple. You need their proprietary V2H system and a transfer/disconnect which is also thousands of dollars installed (one review put it at $7k to $18k just to install that tech) - it’s limited to 9.6kW - and it doesn’t do it automatically. That system uses a CCS plug, so it’s not compatible with cars that use the standard J plug.

[@Sylvan_dB]

@@FuncleChuck I wonder what they are going to do for V2H when they switch production to the NACS connector.

[@ShaneFromSA]

You can install a CerboGX and get the SOC directly from the battery via CAN. No need for the Battery Shunt. Using the CerboGX will also show you and record the cell max and min voltage, battery temperature and other information.

[@ProjectsWithDave]

When I can find some time in my schedule I plan to get one and try it out.

[@jaysway007]

Definitely the best tutorial l have ever viewed. I Liked and Subscribed! Keep up the excellent work, this content is beyond helpful for new novice guys like me, thank you for posting😎👍

[@ProjectsWithDave]

Awesome, thank you!

[@jaybee1570]

I’m a bit confused about the grounding relay in the inverters. Aren’t the ground and neutral bonded in your main panel? If so, why do you need to bind them through the relay in the inverter. Perhaps I’m missing something obvious given the complexity of the setup here.

[@ProjectsWithDave]

When the power goes out, the Victron internal transfer switch moves the emergency panel off-grid. The emergency panel does not have a ground/neutral bond and is now isolated from the house electrical system. You need a ground/neutral bond somewhere in the system so one of the units is programed to create that bond when running off grid.

[@jaybee1570]

@@ProjectsWithDave makes sense thank you

[@YeOldeTraveller]

@@ProjectsWithDave Unless I missed something, you have continuity from the sub panel through the inverters to the transfer switch. All grounds should also be connected together. If that is the case, the connection in the main panel between ground and neutral is still active.. I have a similar setup with a generator in my system. I have to remove the internal connection between ground and neutral. Mu inspector actually asked about that when he reviewed my installation. I created a plug for the full power outlet of the generator to connect ground and neutral. Since that plug and the house cannot be connected at the same time, all is good.

[@Kanuka-Forest]

Great video, clear instructions. I'm about to build a very similar setup, only paralleling two 240v multiplus inverters. Do you not feel the need to install a main t class fuse and battery isolation switch in main battery line, or are you happy to rely on each individual breaker on the batteries?

[@ProjectsWithDave]

I would recommend a T class fuse. I think it's worth the cost for the extra layer of safety.

[@dadbain]

Dave I appreciate your detailed installations and explanations. Could you replace your panels with a single SPAN panel?

[@ProjectsWithDave]

Thanks! I haven't spent a lot of time looking at SPAN panels since they are around $4,000 vs $200 for a standard load center. However, if money isn't a consideration, it looks like a neat solution. If someone want's to send me a panel, I suppose I could try it out. : )

[@dadbain]

@@ProjectsWithDave I also would appreciate a complimentary span panel. 😂 Did that two hundred dollars include wires breakers and that circuit monitor in your auxiliary panel?

[@ProjectsWithDave]

Good point, the panel was about $200, the monitor $165, the breakers, $900. So, about $1,265.

[@NOSPAM-pb4tu]

Wow, thank you so much for the walk-through - For weeks, I've been searching on how to design everything together and you've stepped through this perfectly for me to understand how to wire things and what to use. Once I pull the trigger on my equipment, I'll be sure to use your affiliate links to help contribute to your guides! I do have two questions for you, if you wouldn't mind offering your opinions? 1) In one of your earlier videos (I think your single phase one), you mentioned that the Victrons have inputs for generators. Are they direct connect 50A generator inputs? If so, would you still need the transfer switch if you wire the generator directly into the Victrons? I'm trying to find the simplest way to wire these as I'm very quickly running out of room around my panels. My goal is to just have the generator charge up the batteries directly as quickly as possible, so I can run on limited generator time, then use the batteries to power everything in-between. 2) Many of the batteries I've been looking at state that the suggested battery cycle life is based on the battery discharging to 30% and then charging to 80%. If you don't go through any power outages for a while, is that affecting the battery cycle life to keep it charged at 100% for months at a time? Or do you manually schedule a discharge every so often to keep the batteries maintained? Thank you!

[@ProjectsWithDave]

Thanks for the feedback! The MultiPlus has only one input, you can use it for a generator or grid input, or you can install a transfer switch like my system to switch between them. If you want to connect a generator and grid inputs at the same time without a transfer switch you would need the Quattro series inverter. It has two inputs. I think its a good idea to cycle the batteries once in a while.

[@toddplumlee1523]

What about air conditioning? I have the same sok 5 stack running my RV and that one dometic ceiling unit makes the fridge draw a distant second. Now we are in a heat wave and in Florida of course...my 2400 watts of solar doesn't seem to be enough to recharge the bank in a full sunny day, which is a goal...great video thanks!

[@ProjectsWithDave]

This system should have no problem running an RV air-conditioner.

[@christophercrawford4250]

Dave - thank you for all the work in these great step by step videos. Before I undertake the effort, as we have been suffering with 6+ outages per year, would like to understand the thought behind going with a 50 amp transfer switch and not something higher like a 100 amp - and second, is there a proper location for the transfer switch breaker, like towards the bottom of the main panel or does that not matter? Assuming the transfer switch is present to prevent back feeding from the battery and solar to main - but somehow the main power flows into the inverters/batteries. If power is lost, how does the setup prevent back feeding main? Appreciate all you do!

[@ProjectsWithDave]

The transfer switch in this setup is only there to allow the input to switch between mains and generator. If you use a Quatro ( www.currentconnected.com/product/victron-48v-quattro-3kva-inverter/?ref=pwd ), it has separate inputs for the mains and generator so you wouldn't need the transfer switch. The transfer switch is 50A because that is all the Multiplus II can make use of. If you want more capacity you could get the Quatro 5k or 10k.

[@chrislewis2262]

I watch a video by David Poz showing why you should never hook those style batteries in parallel and to you use a busbar. He's disassembled them and the jumper bar on the inside (that connect bolt red terminals and black terminals together) gets way too hot when a heavy load is applied to it.

[@ProjectsWithDave]

Thanks for the concern. I've seen his video. My system is operating well within the max range for the construction. That being said, a bus bar setup is the more ideal layout.

[@tonysmith9061]

Great video! You should do a follow up video on adding a Cerbo-GX and setting it up to work with the SOK batteries.

[@ProjectsWithDave]

It's already in the works. I have the parts now.

[@jacuzzibusguy]

Great video. Maybe you explained and I missed it, but why are you using a transfer switch rather than routing the main power feed through the inverter?

[@ProjectsWithDave]

The transfer switch allows me to switch between line input or generator input. If you use the Quatro you can bring them both into the unit independently, but the Multiplus only has one input.

[@Goreuncle]

First off, thanks for all the hard you've been doing with this channel, I've used some of your videos for guidance while performing our PV installation at home. 0:50 Dave, are you sure those batteries can be installed in that position? I have a similar LiFePO battery and the manual states that it can't be left in this position (face looking up)

[@ProjectsWithDave]

Yes, this position is ok for the SOK batteries. One negative is dust gets in the terminals.

[@b3owu1f]

So the rack of 5 SOK batts are 2x that of what a single Tesla PowerWall provides right? I assume they have a longer life too being LiFePO4? So at 25Kwh, that's enough energy to run a typical home for a full day in the summer excluding AC? If power were to go out for a couple weeks, and you had solar charging things.. would you basically avoid using anything other than fridge and stove to have enough power (with solar charging assuming you have enough solar)? You mentioned generator too, so I assume you could always use a generator, but was thinking in a situation for someone on an island who may not have access to fuel either.. how long could they last with minimal use of things?

[@JonatanCastro-secondary]

Why not connect the shunt directly to the lynx distributor vs using a cable? 17:32

[@ProjectsWithDave]

So I can mount it independently without putting unnecessary stress on the device.

[@jayb3518]

Great informative video, curious about one thing, why do you need a neutral ground bond in an inverter if your main panel has a neutral ground bond. It seems like your transfer switch isn't switching the neutral, so all your neutrals are together, and all your grounds are together, and then they each connect back to the main panel meaning that there would always be a neutral ground bond in the Main panel, Or did i miss something? Edit - Oh wait, is it because the critical loads panel is only fed from the inverters, and therefore can't really see the neutral ground bond in the main. So the neutral coming from the transfer switch to the inverter isn't necessarily connected to, or passing through the neutral going out to the Critical loads panel, so it's almost a separate system?

[@ProjectsWithDave]

Right, it's basically on an island in UPS mode. The neutral would be floating if one of the inverters didn't' create the ground neutral bond.

[@JerichoGrass]

Dave, this is exactly the system (concept) I would like to build. My current generator transfer switch is a Connecticut Electric "G2" series generator transfer switch. Do you think there is anyway that switch could be used?

[@ProjectsWithDave]

Are you trying to do the same thing where you can switch the input between Grid and Generator? If so, any stand-alone transfer switch should work for that, but I can't say without seeing your actual situation. Watch the single phase install, I talk more about the transfer switch in that video: kzbin.info/www/bejne/eKuwcopuoLxjebc

[@JerichoGrass]

@@ProjectsWithDave Thanks for the reply Dave. After talking with the folks @ CC I've pretty much settled on a pair of Quattros. Simple hookup and totally automatic.

[@LanceTompkins]

If you have more than one rack of batteries how do you configure the dip switches on the next rack compared to the first one?

[@Rich2tsend]

Great video. Watched it twice now. Do you have a circuit layout for the 240 setup? The link appears to have the extra inverter on the parts list but the circuit is still for 120. Thx.

[@Rich2tsend]

Found it!

[@ProjectsWithDave]

Sorry, I posted the wrong link. It's updated now. Thanks! drive.google.com/file/d/1FFBVq8FYKrYMqCA_m_QVGLARbGVuTfC0/view?usp=sharing

[@hectorruiz5120]

awesome video. I love that setup. But I have 12 solar panels with microinverters and I would like to be able to add to my system a battery backup system like that. Any suggestions.

[@ProjectsWithDave]

This system will work as a backup with your setup. They work independently. Inputs and loads can be combined in an AC combiner box like I did in this video using micro inverters: kzbin.info/www/bejne/j2myeKuaf56Wi5o

[@SuperRockmonkey]

Great stuff, very helpful. Don’t you need to install an energy meter so victron can see what the house is using tho?

[@ProjectsWithDave]

You can optionally add a sensor to track that, but it isn't necessary for the purpose laid out in this setup.

[@andyh8239]

If I were to install a pair of 10kw M+2's 1) Can they output to the grid (spin the meter backward) 2) I assume theu have no PV inputs and you would also need an MPPT controller etc... Is there a better sution for a 20kw array to feed the grid while still offering a battery backup?

[@ProjectsWithDave]

It is possible to do it, I show how in this video: kzbin.info/www/bejne/bIiyZWeGlpp4ras However, Victron does not have an approved grid code for the US at this time so you can't get approval to do it. You can use a unit like this one to do both grid back feed and battery backup: signaturesolar.com/eg4-18kpv-hybrid-inverter-all-in-one-solar-inverter-eg4-18kpv-12lv/?ref=pwd

[@alexwegner659]

We currently have our backup system on an interlock switch. Would it be possible to use this same setup through an interlock? And what would the proper wiring be for charging with a generator?

[@ProjectsWithDave]

You can see how I set this system up for use with a generator using a transfer switch in this video: kzbin.info/www/bejne/eKuwcopuoLxjebc

[@earthenergyhex]

Dave have you made a video showing how to connect an AGS to a generator? just an electric start generator.

[@ProjectsWithDave]

Sorry, no I haven't.

[@smashdaworld5916]

Is there a video on how you are monitoring your circuits?

[@stevenlilly]

Question about the ground bonding setup on the inverters.. Since this is not a separately derived system, would it not be correct to have them both set to not have the ground relay enabled? Your neutral bond is still at the main panel in your house..

[@ProjectsWithDave]

When the power goes out the internal transfer switches isolate the hot and neutral conductors from the home system. At that point it is it's own off-grid system and needs a ground/neutral bond.

[@stevenlilly]

@@ProjectsWithDave thank you for the reply.. Does the victron change the bond as well when the power goes out? If not, seems like two bonding points in the system when the power is on..

[@ProjectsWithDave]

That is why I had to make the settings different for each inverter. One inverter is set to no bond, the other is set to create the bond when the units switch to UPS mode. That way the system has only one Ground/Neutral bond.

[@stevenlilly]

@@ProjectsWithDave When your power is on, how do you not have two different bonding points? One at your main panel and one in the Victron? Does the Victron that's doing the bonding change its bonding status between power/no power state?

[@ProjectsWithDave]

Yes, it has a relay that switches to make the ground/neutral bond when in off-grid mode.

[@Irigom]

Your AC Side are running on different phases... they don't need to be same length since they have different loads and different circuits.... the DC side does need to be same length for load balancing since they are going on a shared bus to shared batteries...

[@ProjectsWithDave]

Yes, thanks for noting that.

[@aatirehrarsiddiqui8894]

How about using busbars on the side of the rack for the batteries' (+) and (-) terminals to connect to?

[@ProjectsWithDave]

Busbars add a bit more cost, but are arguably the best solution for balancing the batteries.

[@brianrhodebeck6465]

Expensive way to go I like these videos because I can Make a comment on the solar panels need to go outside.😮

[@ProjectsWithDave]

Yes, this is a nice backup solution, but not a cheap one...

[@ItsEverythingElse]

Have you considered a smart panel sometime down the road? Pretty amazing what you can do with them.

[@ProjectsWithDave]

Do you have a recommendation?

[@JaimetheNomad]

Excellent vid! Also wanted to say I’m glad you kept all your mistakes in the vid, we all make them :)

[@ProjectsWithDave]

Thanks for the feedback!

[@USA-GreedyMenOfNoIntegrity]

Great job my northern solar guru.

[@hectorruiz5120]

Awesome. Finally a video that explain all in a simple way. 👍🏻👍🏻👍🏻👍🏻

[@michaelmay782]

Hey Dave. Was wondering if those units would be big enough to cover 40kwh a day or should I go with 2 5000w units. Gas stove,furnace and tankless water heater. Good videos by the way💯

[@ProjectsWithDave]

It's more about your instantaneous loading. What is your peak load for L1 and L2 throughout the day? An Emporia Vue will help you determine that very easily: amzn.to/41HM1Wj If all your large appliances are gas, including the dryer, you might be ok with 3kW per leg. If you are managing the loads for the whole house and don't want to worry about how many things you are running at one time I would go with the 5K. If you run a 1000W microwave and a 800W toaster at the same time and someone turns on the hair blow dryer and they are on the same L1 circuit you are already maxed out. Hope that helps.

[@buddyt4447]

So these are split phase 180 is there any need for an auto transformer for balancing phases?

[@ProjectsWithDave]

You don't have to, because the inverters regulate the output based on the load for each phase. However, if you had an auto transformer you might be able to achieve higher overall loads in an imbalanced loading condition.

[@ennis437]

If connecting more then one string of batteries could one of the open spots on the lynx distributer be used for one of the battery banks?

[@ProjectsWithDave]

Yes

[@SIGUEL]

You could've done the same thing but waaayyy more simpler (and more features) by going with a SolArk 5k or if you still wanted a bit more work a Schneider XW6048 Pro, but great job and thanks for all the information Victron makes top notch equipment too.

[@barrymclaughlin794]

I am considering the SolArk 5K 2P and I agree about the Victron prices being higher but I think a key difference that shouldn't be overlooked is that the Victron inverters are Low Frequency Torroidal design and the SolArk is a High Frequency inverter. Might make a difference to people with heavy duty motor applications.

[@kuhrd]

These 2 inverter (one per line) setups always seem like a mess to me. You end up with twice the idle power consumption, twice the cableing having to add data communication cables and you split the autotransformer effect across the neutral bar rather than having a single larger splitphase inverter where both half phases are on one centertapped transformer core. You also always have to buy a pair of inverters to keep expanding the setup in the future. This is still a nice setup for a backup situation but I would go with a single 6K splitphase unit for backup power or a single 12K splitphase unit for whole house backup. 2X-4X 12K splitphase units running in daisy chain would be enough to take a modern home that has 200A panel completely offgrid at even the highest usage levels like vehicle charging while using the range, clothes dryer and air conditioner.

[@HealingNestMusic]

Hi Dave, can you help me with my system, it keep pushing power to the grid even I setpoint 10w. Idk what to do.

[@ProjectsWithDave]

Are you actually pushing power back to the grid as a net, or is one leg pushing and one pulling due to imbalanced loads in your home? There is a setting for the sum of both legs or the balanced total.

[@HealingNestMusic]

It keep changing but it pushing -556 w tk the grid. How to balancd the two legs

[@HealingNestMusic]

@@ProjectsWithDave I think you are right, one leg pulling power from the grid, the other is zero,but on the ac ouput but legs has power

[@mikeborkhuis7278]

When wiring the inverter outputs to the emergency panel why tie them into a breaker instead of the main lugs?

[@ProjectsWithDave]

A breaker protects the conductors from the inverter to the subpanel from overload, and provides a quick disconnect for the subpanel.

[@elcomandante31able]

Hello I really enjoy watching your videos very cool set up I would like to get a suggestion I have 5 solars panel mounted in my shed not using any power but now I want to upgrade the system charger controller and inverter and life po4 batteries how can I get this power in to my house I’m not a electrician I now very little thanks

[@ProjectsWithDave]

Here is a video on how I moved power from my shed to my house: kzbin.info/www/bejne/j2myeKuaf56Wi5o

[@elcomandante31able]

@@ProjectsWithDave thanks for the I have 5 solar panels I think they are 210 watts each 36 volts I’m planning to get the victron multiples 24 volts 70 amps I already have 4 lifepo4 batteries 200 ah 24 volts the real question all this set up is that okay?

[@ProjectsWithDave]

If you are talking about the Victron Multiplus II, it is just a charger/inverter it does not take in solar. For that you need a charge controller like I install in this video: kzbin.info/www/bejne/bIiyZWeGlpp4ras

[@matthewcaporale]

I'm considering doing something similar to this / your first video with this system - do the batteries essentially stay fully charged unless grid goes out and it transfers? How do you account for properly cycling the batteries when putting together a back-up only system like this?

[@ProjectsWithDave]

Good question. They do stay fully charged unless the power goes out with this setup. I periodically turn the breaker off and let the loads drain the batteries to cycle them.

[@matthewcaporale]

@@ProjectsWithDave Appreciate the reply and insight, Dave. I'm only going to be doing a 120V critical circuit panel, and I'm bouncing back and forth between the 5k Vitron and the Sol-Ark 5k. I think the Sol-Ark software might allow some parameter programming to cycle the batteries more easily, but it's also the most expensive 120v option. Thanks again.

[@quagmyer7230]

Hi, love this video, I’m wiring the same setup for the same reason you did, (to run my well pump), one question, any particular reason why you didn’t ground the inverter chasis using the same green wire coming in from the transfer switch? I know that’s just for protecting people from getting zapped in case something fails and it has no other functionality that will affect the way it works, just wanted to ask you that.

[@ProjectsWithDave]

This unit is grounded through the Input/Output ground connections.

[@quagmyer7230]

@@ProjectsWithDave makes sense, one more question, I know the ground and neutral should NOT be bonded in a sub panel, only at the main, so, do you run a ground from the main panel to the transfer switch and another ground from the main panel to the sub panel? I’m a bit confused there.

[@ProjectsWithDave]

There is one ground rod for the house. As long as each panel makes its way back to that central grounding rod with a sufficiently sized ground conductor you will be fine. Usually the main panel has a #6 copper connection to the ground rod and the sub panels connect to the central ground bus in the main panel. I always recommend clarifying these details with your local inspector. They often have some "personal" preferences for how they want to see it done.

[@hectorruiz5120]

Dave, With that configuration, how many solar panels do you use and how do you configure them? Thanks for the video and all the information.

[@ProjectsWithDave]

I plan to make that an upcoming video. The system as built in this video is just battery backup, no solar is connected yet. The number of panels you would need would be directly dependent on the load and your solar irradiance conditions. Figure out how much power you consume in a day, and compare that to how much you can expect to produce with various array configurations. Use this calculator to determine your array performance: pvwatts.nrel.gov/

[@USA-GreedyMenOfNoIntegrity]

@@ProjectsWithDavethen double your pv if you are running heat pumps in the winter. You will only get about 5-10% production on cloudy winter days in Kentucky/Ohio areas where we live. 34kWp for me. Adding another 12kWp before winter.

[@bhbaker220]

@@USA-GreedyMenOfNoIntegrity my heat pump heat strips are a 10kW load by themselves (not including the compressor, condenser fan, and evaporator fan and other house loads) and run for several minutes during a defrost cycle. Wish I had gone with a propane heater in retrospect and a mini split for the bedroom to run at night. Thank God for my tankless propane water heater.

[@codyschwoch5451]

My first question is what kind of well pump are you using? That’s 240 V because I have an old jet style well Pump and it’s 120. And my second question is since you upgraded your system, why did you upgrade to still doing single phase inverters when you can now get dual phase inverters for pretty reasonable price nowadays compared to what they used to be instead of buying two expensive inverters to make it so that you can have 220 V at your panel box

[@ProjectsWithDave]

My well pump is a variable speed constant pressure 240V Grundfos pump. The point of this system was starting with a single unit that could later be upgraded to split phase. See the original install here: kzbin.info/www/bejne/eKuwcopuoLxjebc I am also investigating all-in-one split phase inverters. It is hard to find something that beats the reliability and efficiency of Victron. Not hard to find something that beats the cost. : )

[@nickolas1386]

With the shunt inline, does it matter that the lengths to the battery bank are no longer equal?

[@ProjectsWithDave]

No. The connection to the battery is a series connection with only one inverter. You only need to worry about imbalanced lengths with parallels connections. Those would be the connections between the batteries and when connecting parallel inverters.

[@ennis437]

Why would you back feed the panel with your inverse as opposed to using the main lugs?

[@ProjectsWithDave]

It allows me to protect the conductors with a breaker.

[@ForgeAheadwithMike]

If I'm totally mobile (DC only) and want 240V, couldn't I get a MultiPlus II along with an AutoTransformer to make 240V output to my distribution panel? That way I should have 240V and 120V for everything. Correct? I'm guessing I just wouldn't have as much usable wattage compared to two Multis, of course. Basically: Battery Bank > MultiPlus II > AutoTransformer > AC Panel - OR - I could get a European MultiPlus with 230V and change the 50Hz to 60Hz. Pardon anything screwy here. I'm still learning...

[@ProjectsWithDave]

Yes, that's a solution you could use. Here is a video from the guys at Current Connected on the topic: kzbin.info/www/bejne/jqGQanlnn6ekbKc

[@cravenmoorehead3756]

I’m trying to hook up 4 Multiplus 120/3000/48 volt to supply 240. How do I do this.. I have two wired correctly but I want to add two more

[@ProjectsWithDave]

I haven't built that configuration, but you should just be able to configure two units in parallel on each phase. So two units will be assigned to phase one and two units will be assigned to phase 2. The wire lengths need to be the same for the parallel units.

[@cravenmoorehead3756]

@@ProjectsWithDave excellent. I’ll give it a shot

[@rodbhar6522]

What is the point of separating out critical circuits? To prevent someone from baking a turkey during a grid failure?

[@ProjectsWithDave]

Multiple reasons, here are the two big ones: 1) As you mentioned, to prevent rapid consumption of available energy in a power outage from non critical loads. 2) You can save a lot of money by purchasing a small inverter that can run a few critical loads as apposed to a large inverter capable of running multiple large appliances at once.

[@JNHEscapes]

I’m confused regarding the transfer switch. You mentioned if you are not home the inverters can switch from ac assist to generator to make sure everything remains online but that’s a manual transfer switch so the inverters could never automatically pull from the generators. They could turn it own I guess, but the switch wouldn’t switch. For the money I believe I would have used an inverter that could take the ac assist and the generator and eliminate the transfer switch altogether.

[@ProjectsWithDave]

In this setup, the inverters have an internal transfer switch to switch from AC in to battery backup. The AC in can be manually switched between Line and Generator using the external transfer switch. Victron has a more expensive inverter that has two internal switches that can switch between Line, Generator, and batteries automatically. That is this unit: www.currentconnected.com/product/qua10k120/?ref=pwd

[@patrickoneal8284]

Why are you using the ground relay to bond the neutral to ground in one of the inverters? Isn't the neutral already bonded to ground in your service entrance load center? If it is bonded there and that neutral remains connected to the inverters when the ground relay is closed, I believe you have a code violation because you have your ground and neutral bonded at two locations. As I understand it, if you don't have a means in your transfer switch or something else to make and break the neutral to ground bond in the SE panel, your generator and battery backup power should both be setup as a non-separately derived system and the neutral should be left floating in the generator and in the inverters. If I'm missing something, please help me to understand. Edit: I just read the manual for the inverters and see that there is an input safety relay that opens the line and neutral connections when input power drops out, so now I understand why the ground relay would close.

[@ProjectsWithDave]

You got it!

[@TexasCanuck]

Can that unit also be paired with solar and also provide Grid-Tie?

[@ProjectsWithDave]

Yes, I plan to show that upgrade in the future. You can do it with a solar charge controller like this one: www.currentconnected.com/product/victron-smartsolar-mppt-rs-charger-controller/?ref=pwd

[@tlteal]

Dumb question. Is there any reason why you aren't using a lynx power in or distributer as your bus bar for those batteries?

[@ProjectsWithDave]

I didn't need it when I had only one battery to connect.

[@tlteal]

@@ProjectsWithDave aaah, ok thank you for responding makes total sense. I'm building my system right now and learning so it was more of a question than not.

[@gxr3633]

Instead of the Victron Distributor, I went with the Power in and added fuses, M8 nuts and bolts.

[@Scat.original]

What this again Very Impressive. Thank you for a Great video and list of components, tools amd more.

[@62chevrolet]

I’m not sure that matching the AC conductor length matters much. Your phases will inevitably be unbalanced; much more so than an extra 6 inches of wire between the inverter and breaker

[@ProjectsWithDave]

That's correct. Matched lengths only matters for parallel setup.

[@keithcress1335]

Hi Dave! You provided one of those screaming-at-the-video moments! "No Dave, no!!" The AC lines do not, in any way, need to be matched in length. The very fact that they're coming from unmatched, differently loaded utility lines, and the outputs are going to never balanced panel phases while the inverters are not actually even putting out the same voltages, totally ditches the need for that extensive Borg look. You can clean that up anytime the look gets to you. 😉

[@ProjectsWithDave]

Thanks for commenting. I realized that after I had it all installed. The AC line length requirement from Victron in the manual is talking about parallel units, which the split phase setup is not. By the time I came to that conclusion it was too late to recover and I figured equal length wouldn't hurt anything. Plus, I wasn't 100% sure I wasn't missing something about how the units operate when in split phase mode.

[@Scat.original]

What is the model and spec of your generator? Also link to the Transfer switch you are using. Thanks for a great video with steps.

[@ProjectsWithDave]

The transfer switch and all other components is in the parts list on my website, the link is in the description. Here is the link for reference: projectswithdave.com/120-240v-victron-home-backup/ I have two generators, one is 120V dual fuel generator the Maxpeedingrods sent me ( bit.ly/40eKkw2 ), and the and one is a cheap 120/240V unit I bought at a day after thanksgiving sale. I can't say I'm in a position to recommend a generator at this point.

[@leftycbd]

Dave: Two questions: is this install code compliant, and it appears that the only reason you have a transfer switch is so you can switch to a generator, otherwise you could plug the inverters directly into the main panel, am I correct?

[@Jennifer-007]

The reason the Lynx comes with an extra label is so that you can put it on properly if mounting upside down so you don't have to have it look like yours does, if it didn't come with one, get it from your supplier. Page 7 in the manual..."The Lynx modules can be mounted in any orientation. Should they be mounted upside down, so that the text on the front of the units is upside down as well, use the special stickers are included with each Lynx module, so that the text is orientated the correct way." I'm still watching so maybe you fix it at the end, if so disregard.

[@ProjectsWithDave]

Yea, I put it on at the end.

[@Jennifer-007]

@@ProjectsWithDave Great video, thanks for posting it…. Not a lot out there showing the setup AND programming on duals.

[@Jennifer-007]

@@ProjectsWithDave You need a contact link on your web page if you’re not going to have one in your about, which you don’t…. You have a typo on the build page for this project, the word components is missing an n, great build page by the way, well done. The infographic and wiring diagram is better than most I’ve seen that people are charging for… wow nice

[@xxdaftgiantxx995]

why didn't you user the bms of the batteries to comunicate with the winverters now you installed a shunt

[@ProjectsWithDave]

I will be adding solar charging and communication in a future video.

[@cgutowski471]

Fantastic video and love watching your others. Two questions: 1)Since the inverter is the only supply to sub panel wouldn’t it make sense to have a way to still power subpanel for maintenance or replacement of inverters, like an interlock or something with grid into subpanel? 2) When you landed the two neutrals from inverters, looks like one went to main N lug and second went to N bus bar, is that correct?

[@ProjectsWithDave]

I could have set up an additional transfer switch for maintenance purposes, but I don't think it's worth the trouble. I used the main lug for one of the neutral wires because it was convenient and I'm not using it for anything else. A 6AWG wire is large enough for the lug and they all go to the same place.

[@charlieodom9107]

You can install a rotary bypass switch for this very scenario, and I install them on all my setups. The way he has it, if one inverter fails, you lose all power, and a rewire will be necessary to get power back until the inverter is fixed or replaced. An auto transfer switch can fail as well, so having some manual and mechanical method of diverting power makes more sense to me.

[@TylerBell]

Best tutorial like this that I've seen. Subscribed!

[@ProjectsWithDave]

Wow, thanks!

[@nickrhee7178]

Dave, All-in-on inverters offer operating modes such as SBU (solar-battery-utility - use solar first, borrow some from battery if solar is not sufficient, or borrow some from grid if battery is not enough), similarly in SUB mode. Can this split-phase Victron 120/240v be configured to operate in SBU, SUB modes? Also all-in-one provdes options for charging batteries by solar only, or both solar and grid. Charging the battery by grid is not that attractive to me.

[@ProjectsWithDave]

My Victron system is currently setup as a UPS for my emergency circuits. If I were trying to make a system like the one you described, I would use a UL listed all in one inverter. There are some good options on my inverter page listed here: projectswithdave.com/inverters/

[@nickrhee7178]

@@ProjectsWithDave. I was hoping that Victron could be configued to perform all the fucntionalies that all-in-one inverters offer and can do more. I guess they were designed for different applications in mind. I think that I may get a cheap low-freq transformer based 6kw (18kw surge) 120/240v inverter to run my wellpump and septic pump only when i need it because its high idle current. Schneider is transformer based and good but need to buy other components like Vicron, Solark/18kpv are high freq inverters and they may not have high surge capability. Thanks

[@YeOldeTraveller]

I used an autotransformer for branch balancing when I created my backup system. Otherwise, very much the same.

[@nickrhee7178]

Dave, what kind of well pump do you have? I have 1 HP F&W 9 gal/min at 300ft deep, and would like to know if this system will be able to run the pump. Thanks Dave.

[@ProjectsWithDave]

My well is a Grundfos constant pressure variable speed pump. So your pump would be a bit more difficult to run, however the Victron equipment is very good at starting induction loads, I think it would work for you.

[@nickrhee7178]

@@ProjectsWithDave Thanks Dave ! I plan to do the same thing but use two of Victron's Multiplus II 5000 VA so it should handle my current pump easily. I also have septic water pump. If my pump need to be replaced in future I will go with Grundfos soft starting pump but not constant pressure pump. I wish that Victron makes all-in-one split phase (120v/240v) inverters for N American market, it will make the installation much easier. My alternative option is Schneider XW-pro but it also need lots of different components and costs as high as Victron. It would be great if you could make a video about building a system with Multiplus 5000VA and compare with Schneider. Nick

[@ProjectsWithDave]

Thanks for the suggestion, I've been thinking about illustrating a few system configurations for comparison.

[@lyfandeth]

I would have thought that you could have left the 100A rated cable and just changed the fuse from 100A to 50A. That's all it would take to limit that feed, without excess work. I'm also surprised that you don't use "cable butter" on those tight conduit runs. That's what I've seen with senior union electricians. It makes life much easier in tight conduits.

[@ProjectsWithDave]

Smaller breakers do not have large enough lugs for the 100A rated cable I had already run that's why I had to change it. I didn't need any lubricant for the short runs I made. I was even able to push it through from one end. It's the connectors that are a bit tight.

[@BLKMGK4]

​@@ProjectsWithDave Would it make sense to put anything on the wire connections to avoid corrosion? Dielectric or anything else?

[@mirek3542]

Can I connect two different multiplus (48V/3000VA and 48V/5000VA) to one phase with 220V?

[@ProjectsWithDave]

I'm not sure exactly what you are proposing, but the inverters need to be the same to link together. If they are operating as two independent systems I guess you could make something work, depending on the setup.

[@jc_videogooglebrandaccount3926]

In my opinion, the stationary rack is a mistake by SOK and the #1 reason EG4 is selling far more units. I love SOK batteries engineering, but having to customize the rack to have it mobile needs to be fixed ASAP. Current connected needs to be pressing them hard on fixing this.

[@derekr5327]

Great video! I hope you can answer some questions . What is the cost of this whole system and how many hours does it take to complete this project? How does this affect home insurance premiums? Please also talk about permitting process for a project like this. Thank you!!

[@ProjectsWithDave]

Thanks! If you have some wiring experience and all the materials on hand you could do it all in one day. Insurance companies handle things differently you would have to call yours and ask them. Technically this whole system is off-grid so permitting may not be an issue for you. You can ask your building office for advice. I haven't completed the cost breakdown yet. When I do I will add it to the documentation on my website: projectswithdave.com/120-240v-victron-home-backup/

[@BLKMGK4]

@@ProjectsWithDave Insurance companies want to see UL Listed hardware for sure!