diy solar

diy solar

Hi, from Maine

WindWizard

Solar Enthusiast
Joined
Oct 17, 2021
Messages
385
Location
Wilton Maine
This looks like a good place to gather information and to get help on a system I am putting together. I have 9 280 watt panels and a Outback SCC flexmax 80, and a Magnum 4448 inverter. I have 16 3.2v 280ah batteries. I have the SCC and the inverter should be in this week. I ordered wire and connectors. I have the poles and the frames put in the ground for my solar panels. I am planning on using it to cut the electric bill a bit and use it when the power goes out. I am still a bit confused on everything but I will probably be learning as I go like everyone else. I have read a lot of what you have posted and appreciate all of your hard work that you have put in. I took a few pictures of what I have so far done.
 

Attachments

  • 20211017_150649[1].jpg
    20211017_150649[1].jpg
    360.2 KB · Views: 10
  • 20211017_150707[1].jpg
    20211017_150707[1].jpg
    341.3 KB · Views: 10
  • 20211017_150858[1].jpg
    20211017_150858[1].jpg
    223.5 KB · Views: 10
  • 20211017_150912[1].jpg
    20211017_150912[1].jpg
    135.8 KB · Views: 10
Welcome to the forum. Keep us posted on your progress and ask lots of questions.

It looks like the panel mounts have adjustable angles.... Nice.
 
Welcome to the forum. Keep us posted on your progress and ask lots of questions.

It looks like the panel mounts have adjustable angles.... Nice.
Yes, I found that an adjustable tilt would be better for producing power. I found something on youtube that looked like it would work and made a few modifications. I purchased the 2" x 10' poles at farmers union and the super struts at home depot. I found the best place to buy all the 1/2" nuts and bolts was at tractor supply. I used a post hole digger to dig the holes and poured two bags of cement in each hole. They seem to be very sturdy. I am waiting for the 8 awg pv wire to run from the panels to the house. I will probably run the wire before I install the panels. The panels should just screw onto the super struts using 12 2 1/2" x 1/2" bolts with some washers and rubber washers. I plan on 3 panels per structure making a total of 9 panels.
 
I have had my system running for a few months now. I have learned a lot. I found that I had mounted the panels to close so that I had shading on the panels. I had to remove the poles and assemblies and put them elsewhere. I have 12 ground mounted panels 280 watt and I have 12 panels 325 watt mounted on a roof. I have found that if any snow gets on them then it kills the power. I am going to be moving them off the roof in the summer onto some poles. I currently have 16 LifePO4 cells configured as 48v with an Overkill BMS. I have found this to be excellent tool to use to find out from your couch how much power is being generated. This time of year when the sun shines, my batteries are fully charged around noon. I decided to add another 16 Lifepo4 cells and another BMS so that I do not lose out on the power. I tried to use just one Outback FM80 but I was getting nervous when it listed the maximum power input and I was pushing 80 amps, so I decided to purchase another Outback FM80. Synchronizing the two was difficult. I found that one would go into charged and then quit producing power because it was impossible to get the two battery voltage readings the same. The resolution is only 100mv which is not accurated enough to calibrate the two. I found that keeping them in absorb mode works very well with the setting around 55.5 volts. The cells seem to be very happy with that and then when some appliance in the house turns on then the extra power is drawn from the solar panels. I know there is some talk about setting the absorb time to zero but I found this did not work. with the two FM80's. But setting it at 55.5v and then if the batteries are drawn down then it goes back into bulk.

I looked at the price of copper bus bars and it was $10 for a 1 foot piece. The price of material has really gone up. I found that the best bus bar material is copper but a cheaper way to go is just buy a 10 foot piece of 1/2" copper pipe. Cut off the size you need with a pipe cutter and then pound it flat. I looked at the specs on the copper pipe and it is close to 100% pure copper. All you need to do is drill a few holes in it with a drill press and plate it with nickel if you want. The bare copper works fine and if you coat it with a Dialectric grease then it should be okay. I measured the voltage between cells pushing 80 amps into the batteries and the copper pipe bus bar was better than the bus bars shipped with the batteries.

I have my system fully automated to switch between the Grid and the Batteries. Once the battery voltage drops to 50.8 volts then I have it so that it automatically switches the whole house back to the Grid. I have everything in the house on a separate Panel. I call it the Solar Breaker Panel. I switched every single wire from one panel to the other except for the Hot Tub. The Hot Tub was just too much for the MSPAE 4448 Magnum. It can handle everything in the house but the Hot Tub. I track the electric usage and we are using around 25kw per day. When we get sun then I use only 6Kw per day which is entirely the Hot Tub. I am going to modify the Hot Tub so that I am using the Solar Breaker Panel to supply the Hot Tub heater switched in through a SSR. But anyway, my system is working exceptionally well except for cleaning all of the snow off the panels.
I do like the Outback FM80s and the Overkill BMS and the Magnum MSPAE 4448 Inverter. The idle current is basically 0. The Overkill BMS does not even measure it because it is less than a watt. The only issue is when the system switches from the Grid to batteries then we get a light flicker. This is because the Magnum has to wake up and then take on the load.

Electric rates in Maine has just gone up to a tad bit over 20 cents/kw. This puts the typical KW savings at around $4 per day when the sun shines. I have been averaging around $2 a day (some cloudy snowy days) for January and February. I hope to improve that with the extra batteries.
 
Welcome to the party MrWizard

Thank you for including specific info on products. I bet that will save folks some time. (y)

Is your Outback really out back? The pic in your first post looks like it is mounted outside on combustible plywood.

I have found that if any snow gets on them then it kills the power. I am going to be moving them off the roof in the summer onto some poles.
Good idea.
The resolution is only 100mv which is not accurated enough to calibrate the two. I found that keeping them in absorb mode works very well with the setting around 55.5 volts. The cells seem to be very happy with that and then when some appliance in the house turns on then the extra power is drawn from the solar panels. I know there is some talk about setting the absorb time to zero but I found this did not work. with the two FM80's. But setting it at 55.5v and then if the batteries are drawn down then it goes back into bulk.
That calibration work around is over my head. Hope your batteries turn out ok.

I looked at the price of copper bus bars and it was $10 for a 1 foot piece. The price of material has really gone up. I found that the best bus bar material is copper but a cheaper way to go is just buy a 10 foot piece of 1/2" copper pipe. Cut off the size you need with a pipe cutter and then pound it flat. I looked at the specs on the copper pipe and it is close to 100% pure copper. All you need to do is drill a few holes in it with a drill press and plate it with nickel if you want. The bare copper works fine and if you coat it with a Dialectric grease then it should be okay. I measured the voltage between cells pushing 80 amps into the batteries and the copper pipe bus bar was better than the bus bars shipped with the batteries.
I have a laser thermometer to check for "hot spots". I have seen pics of homemade copper pipe buss bars which look like they were laid down on the road to be flattened by vehicles. I've also heard of some folks getting brass bars when they should have been copper. Good luck with your bars, sounds like they work better than well.
I have my system fully automated to switch between the Grid and the Batteries. Once the battery voltage drops to 50.8 volts then I have it so that it automatically switches the whole house back to the Grid. I have everything in the house on a separate Panel. I call it the Solar Breaker Panel. I switched every single wire from one panel to the other except for the Hot Tub. The Hot Tub was just too much for the MSPAE 4448 Magnum. It can handle everything in the house but the Hot Tub. I track the electric usage and we are using around 25kw per day. When we get sun then I use only 6Kw per day which is entirely the Hot Tub. I am going to modify the Hot Tub so that I am using the Solar Breaker Panel to supply the Hot Tub heater switched in through a SSR. But anyway, my system is working exceptionally well except for cleaning all of the snow off the panels.
We run a Hot Tub here and it helps keep us old folks moving. Is yous 240 or 120? I don't know for sure but believe maintaining a constant temp is the best way to go, especially when the power goes out in Winter.
I do like the Outback FM80s and the Overkill BMS and the Magnum MSPAE 4448 Inverter. The idle current is basically 0. The Overkill BMS does not even measure it because it is less than a watt. The only issue is when the system switches from the Grid to batteries then we get a light flicker. This is because the Magnum has to wake up and then take on the load.
Can a small load, an incandescent bulb or sumpin, be put on the Magnum to wake it up prior to flipping the switch?
Electric rates in Maine has just gone up to a tad bit over 20 cents/kw. This puts the typical KW savings at around $4 per day when the sun shines. I have been averaging around $2 a day (some cloudy snowy days) for January and February. I hope to improve that with the extra batteries.
Nice job. Go man go!
 
I have had my system running for a few months now. I have learned a lot. I found that I had mounted the panels to close so that I had shading on the panels. I had to remove the poles and assemblies and put them elsewhere. I have 12 ground mounted panels 280 watt and I have 12 panels 325 watt mounted on a roof. I have found that if any snow gets on them then it kills the power. I am going to be moving them off the roof in the summer onto some poles. I currently have 16 LifePO4 cells configured as 48v with an Overkill BMS. I have found this to be excellent tool to use to find out from your couch how much power is being generated. This time of year when the sun shines, my batteries are fully charged around noon. I decided to add another 16 Lifepo4 cells and another BMS so that I do not lose out on the power. I tried to use just one Outback FM80 but I was getting nervous when it listed the maximum power input and I was pushing 80 amps, so I decided to purchase another Outback FM80. Synchronizing the two was difficult. I found that one would go into charged and then quit producing power because it was impossible to get the two battery voltage readings the same. The resolution is only 100mv which is not accurated enough to calibrate the two. I found that keeping them in absorb mode works very well with the setting around 55.5 volts. The cells seem to be very happy with that and then when some appliance in the house turns on then the extra power is drawn from the solar panels. I know there is some talk about setting the absorb time to zero but I found this did not work. with the two FM80's. But setting it at 55.5v and then if the batteries are drawn down then it goes back into bulk.

I looked at the price of copper bus bars and it was $10 for a 1 foot piece. The price of material has really gone up. I found that the best bus bar material is copper but a cheaper way to go is just buy a 10 foot piece of 1/2" copper pipe. Cut off the size you need with a pipe cutter and then pound it flat. I looked at the specs on the copper pipe and it is close to 100% pure copper. All you need to do is drill a few holes in it with a drill press and plate it with nickel if you want. The bare copper works fine and if you coat it with a Dialectric grease then it should be okay. I measured the voltage between cells pushing 80 amps into the batteries and the copper pipe bus bar was better than the bus bars shipped with the batteries.

I have my system fully automated to switch between the Grid and the Batteries. Once the battery voltage drops to 50.8 volts then I have it so that it automatically switches the whole house back to the Grid. I have everything in the house on a separate Panel. I call it the Solar Breaker Panel. I switched every single wire from one panel to the other except for the Hot Tub. The Hot Tub was just too much for the MSPAE 4448 Magnum. It can handle everything in the house but the Hot Tub. I track the electric usage and we are using around 25kw per day. When we get sun then I use only 6Kw per day which is entirely the Hot Tub. I am going to modify the Hot Tub so that I am using the Solar Breaker Panel to supply the Hot Tub heater switched in through a SSR. But anyway, my system is working exceptionally well except for cleaning all of the snow off the panels.
I do like the Outback FM80s and the Overkill BMS and the Magnum MSPAE 4448 Inverter. The idle current is basically 0. The Overkill BMS does not even measure it because it is less than a watt. The only issue is when the system switches from the Grid to batteries then we get a light flicker. This is because the Magnum has to wake up and then take on the load.

Electric rates in Maine has just gone up to a tad bit over 20 cents/kw. This puts the typical KW savings at around $4 per day when the sun shines. I have been averaging around $2 a day (some cloudy snowy days) for January and February. I hope to improve that with the extra batteries.
Welcome to the party MrWizard

Thank you for including specific info on products. I bet that will save folks some time. (y)

Is your Outback really out back? The pic in your first post looks like it is mounted outside on combustible plywood.


Good idea.

That calibration work around is over my head. Hope your batteries turn out ok.


I have a laser thermometer to check for "hot spots". I have seen pics of homemade copper pipe buss bars which look like they were laid down on the road to be flattened by vehicles. I've also heard of some folks getting brass bars when they should have been copper. Good luck with your bars, sounds like they work better than well.

We run a Hot Tub here and it helps keep us old folks moving. Is yous 240 or 120? I don't know for sure but believe maintaining a constant temp is the best way to go, especially when the power goes out in Winter.

Can a small load, an incandescent bulb or sumpin, be put on the Magnum to wake it up prior to flipping the switch?

Nice job. Go man go!
I will take some more pictures when I get the new cells all setup. The entire setup in down in the cellar. The Outback FM80's are mounted on plywood. If they were to catch on fire then it would not be good. I may need to remedy that situation. The Hot Tub is a 240 volt but I can run the heater on 120 volt. When I change the heater from 240 to 120 Volt the wattage goes from 4kw to 1kw. The Magnum Inverter is 4400 Watt. I agree that putting
I have a laser thermometer to check for "hot spots". I have seen pics of homemade copper pipe buss bars which look like they were laid down on the road to be flattened by vehicles. I've also heard of some folks getting brass bars when they should have been copper. Good luck with your bars, sounds like they work better than well.
I have found that the best way for me to find out how well the connections are working is with a simple voltmeter that measures in millivolts. Once the solar panels kick in and the charge current goes up to 80 amps flowing through the connections it is easy to measure the voltage drop on the battery connections. I was seeing some voltages as high as 20 millivolts. I thought Cell number 8 was defective because it would always using the Overkill BMS show the battery as either over voltage or under voltage. I was about to purchase another Cell. I tightened up the connections and it works great now. I installed one of the flattened copper pipe bus bar and the results are extremely good. The voltage drop on the cell connections is extremely good. I made some bus bars with 0 guage wire and the flattened copper pipe outperforms it. I am in the process of replacing all of my bus bars now with the flattened pipe. I am going to plate them with nickel today. The batteries are placed length wise so I need a 85mm bus bar.
 
No it would be very difficult to do that. It is not a switch but a 30 AMP DP relay. I sense the voltage of the batteries and then apply 12v to the relay to toggle it when the batteries have charged. To do as you suggest, I would need to have an extra delay circuit and another relay and some who knows what else. The system is already complicated so my wife and I deal with the light as it flickers off. When it switches form battery to Grid then it is much faster. The Magnum Inverter kind of flickers a bit during the day especially as heavy loads are placed on it. It takes a few seconds for it to respond to power surges which is totally understandable.
 
The Hot Tub is a 240 Volt with a current of about 6KWatt. I thought about buying another Magnum Inverter but it is a low priority right now.
 
Back
Top