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Adding a battery to a SUN 1000W GTIL

corp9592

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Hello, I am using the common SUN 1000W GTIL with 3 400Wp panels in parallel. The inverter DC input range is 22-60V and the panels peak at 40V.
My intention is to add a battery, but I am unsure whether it is possible using this kind of inverter.

My current scenario is:
scenario_01.png


My intention is:
battery_01.png

Of course I have AC and DC breakers but for the diagram simplicity I left them out.
My question is basically if this proposal is feasible electrically speaking. I know the inverter can work at 2,8V*8 = 22,4V which would be the LiFePo4 battery minimum, but I have doubts regarding the connection of the battery to the solar charge controller AND to the inverter.

Thanks for your inputs.
 
but I have doubts regarding the connection of the battery to the solar charge controller AND to the inverter.
Its as simple as you have diagrammed it with the batteries.

panels peak at 40V
Assuming that the panel Voc is 40v ?

If you are getting a quality SCC, you should consider one that will accept 150v so that you can run your panels in series. This will reduce the wiring and fusing requirements (very important for longer runs from array to SCC).

Something like a Victron 150/35 or 150/50 would fit what you have listed above.
 
Thanks for the (very) quick response.
So you are saying that, let's say I turn the oven on (2000W) and the array is producing 700W, the setup as it is in the diagram will be able to generate 1000W from the inverter (700W from the panels and 300W from the battery) + taking the extra 1000W from the grid, without any other equipment?
Or another scenario. For example what would happen the next morning if I completley discharge the battery at night? What will be done in the first place, charge the battery or feed the inverter?

I am a little bit ashamed because I feel this is basic knowledge (since I am a computer engineer) but electricity has its own tricks.

The panels Voc is 49.8V and it Vmp is 41.8V. The idea of putting them in series is a good one. I was in the parallel mindset because the inverter input range, but since I am taking apart the panels from the GTIL...

Looks good!
Thanks!
 
turn the oven on (2000W) and the array is producing 700W, the setup as it is in the diagram will be able to generate 1000W from the inverter
No, your inverter will beep loudly and shutdown with an overload error.

Your oven would be connected to the inverter, not directly to the array (as you have drawn it).
 
Hello, I am using the common SUN 1000W GTIL with 3 400Wp panels in parallel. The inverter DC input range is 22-60V and the panels peak at 40V.
My intention is to add a battery, but I am unsure whether it is possible using this kind of inverter.

My current scenario is:
View attachment 33277


My intention is:
View attachment 33279

Of course I have AC and DC breakers but for the diagram simplicity I left them out.
My question is basically if this proposal is feasible electrically speaking. I know the inverter can work at 2,8V*8 = 22,4V which would be the LiFePo4 battery minimum, but I have doubts regarding the connection of the battery to the solar charge controller AND to the inverter.

Thanks for your inputs.

that is exactly the system I am putting together.

The only real issue is that those inverters state that they should be used with 36V or 48V batteries (check specs on Amazon).

The Chinese datasheets state that the inverter will work with a 24V battery as long as it puts out over 26V initially, but there have obviously been enough customer complaints (and returns) here in the US that they have backed off the ‘US Specs’ to be more conservative as far as minimum battery voltage.

So how well these will work when powered by a 24V LiFePO4 battery is the greatest risk I see.

I’ve got enough cells to power with an 8S 12S or 16S LiFePO4 battery, so I plan to test and see which lowest battery voltage I am comfortable works reliably.

For sure, you need to pay attention to cable resistance between battery and inverter if using an 8S LiFePO4 battery - the inverter needs to see 26.0V at some level of current to start up properly...
 
@MisterSandals the inverted has a built-in power limiter that (I believe) can be set to, let's say, 950W to it doesn't generate more power than it is capable.

@fafrd thanks for your input. Yesterday I tried to power the inverter with 2x12V VRLA batteries at 25V and it started ok, putting 200W to my house (since that is what I was demanding). What you say troubles me, since I don't want to spend hundreds of euros to a battery that won't work with the inverter...

Thank you both!
 
the inverted has a built-in power limiter that (I believe) can be set to, let's say, 950W to it doesn't generate more power than it is capable.
Interesting. So what is the behavior when you plug in a 2000w appliance to a 950w "limited" inverter? Does it send 950w quietly without complaint? This seems troublesome.
 
Interesting. So what is the behavior when you plug in a 2000w appliance to a 950w "limited" inverter? Does it send 950w quietly without complaint? This seems troublesome.
You don’t plug load into these inverters. The inverters plug into a socket and inject up to their maximum power output into the socket.

So, for example, if you have the sensor on L1 and run a load of 2000W, the inverter will max out and inject a total of 950W into L1, meaning grid consumption will be reduced from 2000W to 1050W.

The sensor prevents the inverter from exporting to the grid. As long as consumption exceeds the inverter’s max output, the inverter will be maxed out and net consumption will be reduced by that max number of Watts.

When consumption is less than inverter max output, the sensor will limit the inverter output to that consumption minus a small amount (~10W, I believe) so net consumption will be maintained at that small level.
 
Fafrd is correct, this grid tie inverter will suppliment the load when it's over the specified current of the inverter and more power will be drawn from the grid to power the load at its operating current.


I currently run my TV, CCTV system etc via a inverter but I am thinking of getting one of these grid tie inverters and keep the other one on for my shed's.
 
Fafrd is correct, this grid tie inverter will suppliment the load when it's over the specified current of the inverter and more power will be drawn from the grid to power the load at its operating current.


I currently run my TV, CCTV system etc via a inverter but I am thinking of getting one of these grid tie inverters and keep the other one on for my shed's.
What will really twist your noodle is that one of these GTIL inverters can be used to ‘boost’ a 120VAC PSW inverter by ~750-1000W.

For example, I have a 3kW high-frequency 120V PSW inverter that I use to power my fridges when the grid goes down (by the utility for fire prevention).

By placing the GTIL clamp sensor on the hot leg from the 3kW inverter, the GTIL will generate up to 750-1000W to add to the total power.

If I was maxing out the 3kW PSW inverter powering loads and turn on the GTIL it will reduce load on the 3kW PSW to 2000-2250W, meaning I can now power an additional load of 750-1000W and the PSW has the ‘headroom’ to supply the needed additional power…
 
I wouldn't of thought about parrallel with a inverter because the sine wave can get really dirty, just got up can not think straight yet lol
 
What will really twist your noodle is that one of these GTIL inverters can be used to ‘boost’ a 120VAC PSW inverter by ~750-1000W.

For example, I have a 3kW high-frequency 120V PSW inverter that I use to power my fridges when the grid goes down (by the utility for fire prevention).

By placing the GTIL clamp sensor on the hot leg from the 3kW inverter, the GTIL will generate up to 750-1000W to add to the total power.

If I was maxing out the 3kW PSW inverter powering loads and turn on the GTIL it will reduce load on the 3kW PSW to 2000-2250W, meaning I can now power an additional load of 750-1000W and the PSW has the ‘headroom’ to supply the needed additional power…
Would be great to see a schematic/photos of that.
 
I have exactly what your "intention" is & have been using it for months.
It works exactly how you think it would - it gets power from either the battery or battery + charge controller. I commonly see both batt & SCC providing power in the mornings.

I have 4 x 390w panels, 2S+2P, so 80v and use a Victron 100/50 controller.

Works really well - just wish I went 2000W with 48v initially.
 
I have the same as well for just over a year.

2kw of panels to charge controllers to batteries.

Inverter to batteries, only ever done 36v and 48v batteries but i cant see why 24v wouldn't work, they are pretty programmable.

3 pin plug into my garage which has a feed on its own breaker at my panel.

I am very happy with it, extended the ct clamp with some CAT5 shielded about 20m to get to the panel.

I have it plugged into a smart plug that does energy monitoring so i can see how much solar i have produced / covered for the house. Then have a raspberry pi and usb to serial connected for battery voltage out of the inverter.

My smart meter is roughly zero +/- 10w as it fluctuates with house load.

Only thing i wish it would do is allow remote configuration, for example if you could set the battery cut off high during the day to say 58v I could keep my batteries charged ready for high loads around tea time when there isnt enough solar.

I am considering buying a second one without solar to setup as a house battery, charge during off peak and then come on during peak but i could just expand my current batteries which i charge off peak anyway.... Decisions decisions.
 
I have the same as well for just over a year.

2kw of panels to charge controllers to batteries.

Inverter to batteries, only ever done 36v and 48v batteries but i cant see why 24v wouldn't work, they are pretty programmable.

3 pin plug into my garage which has a feed on its own breaker at my panel.

I am very happy with it, extended the ct clamp with some CAT5 shielded about 20m to get to the panel.

I have it plugged into a smart plug that does energy monitoring so i can see how much solar i have produced / covered for the house. Then have a raspberry pi and usb to serial connected for battery voltage out of the inverter.

My smart meter is roughly zero +/- 10w as it fluctuates with house load.

Only thing i wish it would do is allow remote configuration, for example if you could set the battery cut off high during the day to say 58v I could keep my batteries charged ready for high loads around tea time when there isnt enough solar.

I am considering buying a second one without solar to setup as a house battery, charge during off peak and then come on during peak but i could just expand my current batteries which i charge off peak anyway.... Decisions decision

I have the same as well for just over a year.

2kw of panels to charge controllers to batteries.

Inverter to batteries, only ever done 36v and 48v batteries but i cant see why 24v wouldn't work, they are pretty programmable.

3 pin plug into my garage which has a feed on its own breaker at my panel.

I am very happy with it, extended the ct clamp with some CAT5 shielded about 20m to get to the panel.

I have it plugged into a smart plug that does energy monitoring so i can see how much solar i have produced / covered for the house. Then have a raspberry pi and usb to serial connected for battery voltage out of the inverter.

My smart meter is roughly zero +/- 10w as it fluctuates with house load.

Only thing i wish it would do is allow remote configuration, for example if you could set the battery cut off high during the day to say 58v I could keep my batteries charged ready for high loads around tea time when there isnt enough solar.

I am considering buying a second one without solar to setup as a house battery, charge during off peak and then come on during peak but i could just expand my current batteries which i charge off peak anyway.... Decisions decisions.
I threw out my cat 5 and only have cat 6 left, I am hoping to extend mine when it's delivered.

The alternative I can see is have a timer, a relay and a voltmeter (for when you limit the voltage).

When the timer is on the relay switches to the voltmeter and when the voltage goes down switches a main relay off, when the timer turns off the relay goes to normally closed and works the inverter as usual.

Hope you see what I am trying to say here, not that hard to put it together.

Any how tired and bedtime
 
that is exactly the system I am putting together.

The only real issue is that those inverters state that they should be used with 36V or 48V batteries (check specs on Amazon).

The Chinese datasheets state that the inverter will work with a 24V battery as long as it puts out over 26V initially, but there have obviously been enough customer complaints (and returns) here in the US that they have backed off the ‘US Specs’ to be more conservative as far as minimum battery voltage.

So how well these will work when powered by a 24V LiFePO4 battery is the greatest risk I see.

I’ve got enough cells to power with an 8S 12S or 16S LiFePO4 battery, so I plan to test and see which lowest battery voltage I am comfortable works reliably.

For sure, you need to pay attention to cable resistance between battery and inverter if using an 8S LiFePO4 battery - the inverter needs to see 26.0V at some level of current to start up properly...
The specs from the manufacturer says 25v starting current then can use 22v as a minimum
 
When I get the build done and test out whether this ‘inverter peak capacity boost concept works, I’ll draw up a schematic and post my results…
Hope it doesn't fry your inverter, fingers crossed it doesn't
 
Just a thought but I saw a YouTube video and about pressing the settings button and the up arrow (I think it was) and this opens a setup menu, there you can switch the settings from solar to batteries etc etc, haven't tried it yet still waiting for delivery
 
Just a thought but I saw a YouTube video and about pressing the settings button and the up arrow (I think it was) and this opens a setup menu, there you can switch the settings from solar to batteries etc etc, haven't tried it yet still waiting for delivery

not possible - as there's only 1 input to the units, its on or off.
In the diagram in post 1 the battery & solar is connected together, the inverter doesnt know if its battery power or solar power its seeing.

I tried it yesterday, was getting ~1000W from the panel & had a full battery, so set the inverter to output 600W flat.
It was using the solar/charge controller only & didnt draw from the battery, once the sun went down - more & more came from the battery.
 
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