DIY Tesla powerwall

[Ampster]

Time to install a critical loads panel!

The demonstrates the value of being adaptable. What are you planning on doing to switch between your inverter and the grid in case you need to work on the inverter?

Eisenhower said, on the eve of D day, " Plans are nothing, planning is everything." I am a firm believer in the right to generate our own power and even though I have a GT inverter there is a lot more stuff behind the meter that is none of the business of my utility. They will just see less consumption from me. Longer term I am working on a plan to upgrade my pack and self consume more of my solar.

 

[JoeHam]

Time to install a critical loads panel! My initial hesitation was finding 2k worth of constant loads. It's a real balancing act, finding circuits that will use all of the 2400 watts my inverter can provide but not go over. I've settled on 4 circuits; front fridge, back fridge, kitchen lights and kitchen outlets. Those first four should stay well within my limits. I have room in the critical loads panel for 8 breakers or 16 circuits, so I'll add more until I reach my 2.4k max. I'm pulling wires now so more to come soon!

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So I don’t understand why you need exactly 2000w of load. Why don’t you start small, say put one fridge on it for a week and add loads if that goes fine.

I plan to do the same thing at my house with a 48v LiFePO4 system. I will have a load panel COMPLETELY SEPARATE FROM THE GRID and I will wire circuits to it until it is using say 50-80% of the system capacity and I will stop there.

IF I get the bug to do more I can add more panels and batteries and inverter capacity and then move more circuits off grid.

Just a thought for you to consider.

 

[sed6]

In progress.



All done.



So now my inverter goes to a 20 amp breaker, that feeds my critical loads panel.

If the grid goes down I'll have power to my critical loads, I also tied my critical loads panel into my main panel with a double pole breaker. I am still trying to figure out a safe way to feed both legs of my main panel from my inverter. Right now only one leg is fed. I almost fed both legs before I realized that's not safe unless my main breaker is off, that's what the red wire nut is. I know in a pinch, like a long term outage, I could just jumper between the two halves of a double pole breaker, but again, not so safe. Does anyone know a correct or safe way to feed both legs of my main panel with 120?

 

[sed6]

So I don’t understand why you need exactly 2000w of load. Why don’t you start small, say put one fridge on it for a week and add loads if that goes fine.

That's a good idea and what I plan to do. I don't need all 2kw to be used I just want to maximize the inverters potential.

 

[Ampster]

I don't know what NEMA says about powering both legs from one phase. I think it is done in RVS with an adapter because they plug into 240 and 120 for shore power. For the time being why can't you use only one phase of the sub panel and feed that from your inverter? Is there some backfeed prevention in that arrrangement? Is it your intention to power the critical loads all the time from your inverter?

 

[sed6]

I don't know what NEMA says about powering both legs from one phase. I think it is done in RVS with an adapter because they plug into 240 and 120 for shore power. For the time being why can't you use only one phase of the sub panel and feed that from your inverter? Is there some backfeed prevention in that arrrangement? Is it your intention to power the critical loads all the time from your inverter?

I sure can and will just feed one leg for now. It's not that critical that I feed both. I do plan to power my critical loads via my inverter.

My electrician neighbor took a look and saw a couple of concerns. #1 that red wire nut, he suggested I just pull that red wire out (he suggested that a transfer switch might work to power the second leg instead). #2 the THHN from my breaker to my critical loads panel should be in conduit (or use Romex instead), but says since it's in the wall only about three feet straight up and back down that I'm okay.

Still have to run the wire from my inverter to my panel, going to do that now.

 

[Ampster]

I am fine using .5 volt increments for my settings at the 48 volt level. At the BMS cell level I generally use two decimals. I will work up a table with the offsets from my Fluke, my Outback Skybox and my BMS as suggested on another thread. Currently my settings are all pretty conservative but not calibrated between devices. I will have to change everything when I commission my new pack because the chemistry is different.

 

[sed6]

I put the finishing touches on last night, painted the battery frame and applied a decal.

 

[sed6]

I found a small windows tablet I wasn't using and installed MPP's Solarpower software.

 

[pawanranta]

The project looks great. What is your roof pitch?

 

[sed6]

The project looks great. What is your roof pitch?

Thank you! 8/12 or about 34 degrees and my latitude here in OKC is 35, so perfect!

 

[pawanranta]

That means around 33 degree tilt angle. Do you get any rebates for installing solar in your state?

 

[sed6]

That means around 33 degree tilt angle. Do you get any rebates for installing solar in your state?

I wish! Oklahoma is ruled by the oil and gas companies so anything that offers them competition is a big no-no. The net metering here is a joke too. So is permitting and inspection which is why I skipped that too. Leave it to the government to make honest people into criminals. Here in OKC it is literally a crime to install a ceiling fan without a $70 permit, which you can't get unless you pay a licensed electrician to pull a permit and do the install. I know most of us try to follow the rules but sometimes big brother makes it too hard and you have to say f#$% it and follow common sense instead.

 

[JoeHam]

I wish! Oklahoma is ruled by the oil and gas companies so anything that offers them competition is a big no-no. The net metering here is a joke too. So is permitting and inspection which is why I skipped that too. Leave it to the government to make honest people into criminals. Here in OKC it is literally a crime to install a ceiling fan without a $70 permit, which you can't get unless you pay a licensed electrician to pull a permit and do the install. I know most of us try to follow the rules but sometimes big brother makes it too hard and you have to say f#$% it and follow common sense instead.

You should be eligible for a federal income tax credit.

 

[pawanranta]

I wish! Oklahoma is ruled by the oil and gas companies so anything that offers them competition is a big no-no. The net metering here is a joke too. So is permitting and inspection which is why I skipped that too. Leave it to the government to make honest people into criminals. Here in OKC it is literally a crime to install a ceiling fan without a $70 permit, which you can't get unless you pay a licensed electrician to pull a permit and do the install. I know most of us try to follow the rules but sometimes big brother makes it too hard and you have to say f#$% it and follow common sense instead.

Solar panels are heavily subsidized here in the Victoria state of Australia.

 

[sed6]

I picked up one of Will's recommended coulometers off Amazon. His paid link: https://amzn.to/2XKZby4



I struggled over where and how to place it. Eventually I just removed the shunt from its case and bolted straight to my battery terminal.





And I'm going to start my first capacity test tonight. I plugged in an optimistic 480ah capacity and at 25.2 volts I reset to 100% and off we go.

I plan to keep the Cell Meter 8's as they do a great job showing individual cell voltage and supposedly passively balance the cells..

 

[sed6]

I've started to collect cells to build some battery packs.

 

[pawanranta]

What's p to r?

Probably P to N?

 

[pawanranta]

I've started to collect cells to build some battery packs.
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View attachment 14071

Hey Sed6.. Are you done with building the battery pack?

 

[madmax]

I am close to clicking the buy button on this myself, however, do you know if this can be used 100% off grid? I'm going to be powering a standalone shed

Yes, it can work completly off grid. As far as I can tell the only difference between the lv2424 hybrid and some of the older variants is the grid tie option and being able to operate on split phase with 2 units and 2 parallel kits), all while keeping a 24v setup.