Growatt Split Phase \ Off Grid \ Backfeed Home Battery Backup

Overview of my off grid Growatt split phase installation. Also capable of backfeeding the main panel during a power outage.
Products on build:
TEMCo 1\0 AWG Cable:
www.amazon.com/gp/product/B00..."
TKDMR 1/0 Terminal Lugs
www.amazon.com/gp/product/B08...
TEMCo Hammer Crimper
www.amazon.com/gp/product/B00...
Klein Tools Wire Stripper
www.amazon.com/gp/product/B00...
0:00 Intro
0:39 Specs
1:42 Inverters
2:57 Batteries
4:00 DC Wiring
5:19 AC Wiring
6:21 Backfeed

[@NCislander]

Nice setup. I like the "StandOff" idea, great solution (Neater Cabling-Cooler Units). I also like the recommendation on how you performed the Ground/Neutral Bond issues. I am putting together a similar 48v Growatt 5000ES Dual System. Great ideas on your build. Thanks for sharing.

[@lifewithlonsi]

Thanks - good luck with your build!

[@George-jy7op]

GREAT video, informative with facts and values. As a retired electrician, Not Bad. Your reasons for standing off the inverters are valid but, you really reduced the hazard of fire greatly. Win-win😊

[@lifewithlonsi]

Appreciate the feedback, and great point re: fire hazard!

[@awbean5254]

GREAT, NEAT & WELL THOUGHT OUT PROJECT.

[@lifewithlonsi]

Thank you!

[@kc79ta]

I have a very similar set up using the 2 Growatt inverters. Nowhere as clean as yours is. It's been running my off grid shop/garage, and 2 Mini splits on my house for 1 year now. I had 2600 watts of solar, and found that it was just enough in 110 deg Texas heat. I also use it as backup for the house if needed, so I always try and keep the 4 - 24v/100Ah batteries at least at 70% SOC if needed. I had to use it 4 times this spring (lots of bad weather), and it worked great. I just bought, and am currently installing another 2400 watts of solar to make sure batteries are better topped off when the sun goes down. I have their AC charger also, but the 30amp version and love it, thinking about getting another, so I can use my gas generator to charge the batteries faster if no sun is available during a power outage. Nice work.

[@lifewithlonsi]

Very cool - I'm in the middle of installing a 50a inlet to backfeed my panel which I plan on using to charge my batteries (by grid or generator) to supplement my panels. Broke my collar bone with the work half done so it's going to sit a while! I'll post a vid on that once I'm back into it. Thanks for sharing, your setup sounds great.

[@malakyahwalker6473]

GREAT JOB ,I have the same 24v split phase system for approximately one year , with five EG4 batteries. I power a single wide mobile home with a mini split

[@lifewithlonsi]

Very nice - glad to hear they're doing the job!

[@timmathewson3910]

Nice video, thanks for sharing.

[@lifewithlonsi]

Thank you, I'm glad you liked it!

[@TheTundercat222]

it works and looks good

[@lifewithlonsi]

Thanks!

[@richrock1548]

First off, really nice clean installation! But in my opinion EG4 or Mpp solar inverter/charge controllers make more reliable units with higher voc allowing you to put more panels in series which I prefer. In tests that I have performed and also seen online, partial shading on a parallel configuration lowers the wattage coming in just as much as series. In essence a higher voc is always better in any case.

[@lifewithlonsi]

Good info - thanks. I've been seeing all of the new EG4 stuff come available and it looks great, I wish it had been an option when I purchased all of this but there's always round 2!

[@MR_Garage]

In the middle of planning something very similar. Primarily because I already have 6.8kWh of solar on the house (sunpower, IQ7 micro's). Looking to tack on batteries for backup and also cover peak time costs.

[@lifewithlonsi]

Awesome, hope the video helped!

[@boblatkey7160]

Dude! Understand the difference between power and energy and get your units straight otherwise you are talking gobbledygook!

[@motec5]

24 volt is just fine, survival voltage, i too would build with 48 volt if i had to start over but i am invested now!

[@lifewithlonsi]

Haha. Thanks, that makes me feel better :)

[@bimmers323ci]

cool

[@lifewithlonsi]

Thanks!

[@jtr82369]

That's an incredibly clean setup and I really like how you kept the boxes separate. I have the same invertor and can set the AC charging amps if I set the battery to USE instead of LI with the comms, of course that loses the little features you gain from LI but it's a work around for you until you get solar or your charging system setup. Sig Solar told me I can have multiple chargers running at the same time, might your only option with 24v. How is your Growatt WiFi dongles working? I have had terrible luck so far and it's only monitoring, so I am ordering the Solar Assistant kit from Watts247, it's called the Solar Assistant Orange Unit and allows you to monitor 10x more data and control remotely from your own domain, all the data is houses locally.

[@lifewithlonsi]

Thanks for the tip - that's what I figured on the battery type setting, I may make that change for the short term. The wifi dongles appear to be working ok, I don't have the system on all the time so I don't have any long term observations but I was able to get them setup and transmitting data without any real issue. I'll have to check out that kit though...

[@lts30000]

Have you already got a read wright cable for the batteries to rewrite firmware ?

[@buixote]

So I've got the 2x5000ES, with two midpoint transformers. I've got a transfer switch and 6 EG4 48v batteries. We use it for "time-shifting" and backup... I've got a manual transfer switch but am trying to figure out an automated one... the inverters can be programmed as to when to run, so I figure if I get one of these "backup generator" ATS's, and wire it with the *grid* as the backup power source, that will do the trick. None of the companies who make this hardware will talk to me, since they just want to sell me a generator... If you, or any of your viewers have any thoughts, I'd welcome them. Your setup looks very clean, thanks for the video! -- Bill

[@lifewithlonsi]

I've never played with an ATS but from my understanding in theory that should work. Inverter output is no different than a generator so just swapping out the source should work fine. I think the devil will be in the details on how\when you are switching and what the trigger will be - that will ultimately be up to the ATS and what it supports. Interested to hear if others have experience ecommendations on this one.

[@boblatkey7160]

Dude! When you shift time, where do you go?

[@donbeal6777]

Nice video. Just a heads up, Option 11 will allow you to limit utility charging current. I have mine set to 14amps so I can use normal 12/14gauge extension cords.

[@lifewithlonsi]

Thanks, I need to double check but when I first setup, setting the battery type to LI disabled that option. I believe you need to set battery type to User to open it up, which I should just do.

[@donbeal6777]

@@lifewithlonsi You're correct. I set that up awhile back and forgot that setting forced me to enable 'User-defined'.

[@benkanobe7500]

I am doing the same thing. I purchased the 24 GW too. I wish I purchased the 48. Anyway, maybe I can sell it or find another use for it. How do you have two BT Dongels for the GWs and how are you able to read them independently? Don't they appear with the sam number identifier? I want to have two but do not understand how they work when there is two.

[@lifewithlonsi]

I was able to register both dongels to the same tenant so the data is sent to the same dashboard. I'll check it tonight, my login seems to have expired - but I remember it being a fairly straightforward process.

[@leafnutz2341]

Nice clean setup with some good creative work. Setting 11 can be changed to limit your Utility charging current so you can charge from the grid with a standard outlet. Are you using battery communication? How are you using 1 PV disconnect (I only see 2 PV conductors) with 2 inverters?

[@lifewithlonsi]

Thanks - in the manual setting 11 says that it cannot be changed if LI is selected in setting 5 (which I have). I haven't actually tried it though, and I guess I could try using User instead of LI and see if that works. I do have battery communication setup. For PV - I haven't finished setting it up but I'm only going to have one small array. I'm not really planning on running any large loads off PV so my plan is to feed only one inverter and just small loads off of that leg in the panel and use PV to slowly charge batteries if needed during an outage.

[@leafnutz2341]

@@lifewithlonsi I believe you are referring to setting 2 which doesn't allow changing if using "Li" mode. Setting 11 allows you to change utility charging current even if using "Li" mode.

[@lifewithlonsi]

Thanks, I will give a try this weekend!

[@ko2890]

I have two 48 V Crowatt ES inverters and am basically building the same system. However Growatt says that 4 gauge wire is to be used. Originally Signature solar said to use 2 gauge wire which was almost impossible to fit into the inverter and did not fit into the Nader breakers they had me buy. Does the growatt manual say to use 1/0 wire or did you just use it?

[@lifewithlonsi]

The manual on mine calls for 1x2AWG or 2x6AWG for 24V and 2x8AWG for 48V on a 200AH bank. I threw that out and went by the max amp ratings which is 141A on 24V and 71A on 48V and sized my wiring based on that AND the loads I will be running. To do it "right" by many folks standards it would have me running 2/0 for the inverters and 4/0 between bus bars.

[@ko2890]

@@lifewithlonsi Thanks for getting back to me. I started with 2/0 wire but almost broke the inverter opening fringes getting them attached. Went to 4 gauge as the manual stated, but have now got 1/0 wire coming. The 2/0 gauge did not work with the breakers I want to use, from sig solar, and 1/0 gauge will work with them. Finding that this is a bit of trial and error. Hope that in a month this thing actually is turned on!!!

[@MrShaneo369]

Btw where did u source those bus bars on the side of your batteries?

[@lifewithlonsi]

I'm going to try it - with battery set to LI the manual says the amp limit is disabled. I'm going to switch to User and see if that works. The bus bars are from Rysz Battery in CT. ryszbattery.com

[@woodzyfox4735]

you WILL want some air flow in that box. small PC fan on one side and some holes

[@lifewithlonsi]

That's a good point. The ends are detachable, I'll mount a 140mm fan on each side and pull air through. Thanks for the tip!

[@josephbowles4995]

Ok my question is you say your setup last two ok I have almost the same setup I have two alpha5 48 volt rack mount batteries from Rich Solar and two 3000 watt 48 volt inverters from rich solar that are exactly inside and out like the growatt and I have 10 200 watt solar panels plus I’m tied to the grid but it’s solar first then grid if no sun My batteries will only last one night if I’m lucky I know that I’m doing something wrong or there’s something wrong but I’m not sure what that is. Everything seems to be working fine but I can’t seem to get these batteries to last more than one night and I know they should any ideas where I’m going wrong Thanks

[@lifewithlonsi]

Hi - it really comes down to your draw on the system. When I say 2 days, that is cutting all non-essential loads - I am really just running a few lights, my well pump as needed, heat\ac sparingly etc. I shut off all of my nice to haves in an effort to stretch power. Do you know your phantom load (how much power is constantly being drawn)? With all my stuff on I'm around 450w but I cut that to around 200 if I'm trying to conserve. Plus the inverters add roughly 75w to that number as well. My house pulls roughly 25-30kWh this time of year when it's business as usual, so yes, if I were to leave as is then I would likely get ~12 hours out of it.

[@uhjyuff2095]

Can't use the built in charger on the inverters to charge a battery? The batteries do have bmses built in so maybe you can change the settings and rely on the bms to protect the battery from an overvoltage event, idk.

[@lifewithlonsi]

I can, but I need to change the battery type to User instead of LI, I'm not 100% sure what functionality I give up by doing that but it is on my list of things to test.

[@MrShaneo369]

You can actually limit the charge amps from the inverter

[@dr.projectx5142]

Can these do 3 phase ?? For like running machine and motors??

[@lifewithlonsi]

Yes they can - see pg 31 of the manual, shows wiring diagram for parallel setup in 3 phase signaturesolar.com/content/documents/GROWATT/1519008-manual.pdf

[@MichaelPittmanJr.]

I have the same growatt. I'm unsure if I want to buy another to parallel them. Would you recommend just buying a different brand or does it seem to work well.

[@lifewithlonsi]

These seem to work fine. I've run my house off them a few times with no issues. That said, there's a lot of new stuff out and if I were building today I might go a different route. The Eg4 inverters look interesting and I believe they are UL listed which is a plus

[@lifewithlonsi]

Just saw an email from signature solar and made me think of your comment. They have a special on a parallel kit with a wireway\breaker box that looks really cool. signaturesolar.com/eg4-13kw-off-grid-split-phase-inverter-bundle-2-x-6500ex-48-13000w-output-16000w-pv-input-split-phase-120-240vac-all-in-one-solar-inverter-system/?_hsmi=269051297&_hsenc=p2ANqtz--aDD0GA_uXTlTOqPPL5c8awc_iYIGxGRzdGHgmNUwqB_pV0KJ3eX79tR1119_lrWobiLASOuhiU10UmYdV8en6Xo1yXA

[@herbertvonsauerkrautunterh2513]

I still don't get what split phase is.. I will be using a single MMP 6000w inverter with 2x 48v jakiper batteries and i will be powering my house light and PowerPoint circuits off grid and islanded. The circuits will still be connected to the grid via a the way changeover switch just in case. I'll be moving the breakers and sticks green the main meter box board to a sub board inside my house for easy access and control. I keep watching these north American videos where sind of the stuff doesn't make sense. It's the same but a bit different here in Australia..😮

[@lifewithlonsi]

Here in the US most residential power comes in from the street with 3 cables - Line 1 - 120volts, Line 2 - 120 volts, and a Neutral. Split phase refers to the two hot 120volt lines, each of which powers half the circuits in the panel (or each phase). To backfeed a panel you need to apply 120 volts to each leg in the panel so you need two hot lines coming out of the inverters. These inverts supply 1 hot line each, so setting them up in split phase means each inverter will power 1 leg in the panel with a shared neutral.

[@boblatkey7160]

Split phase is 240 V line to line and 120 V line to neutral.

[@herbertvonsauerkrautunterh2513]

So two phases?

[@TexasCanuck]

So not Grid-Tie? I want Grid-Tie+Battery Backup.

[@lifewithlonsi]

Correct, no grid-tie on this setup. That requires a lot more in terms of coordination with utility, permitting etc. Also, most grid tie systems out there will be offline during an outage - so you are left with what's in your batteries until the grid is back online, in the typical setup, solar goes down with the grid. I want my system generating solar power when the grid is down!