noob trying to upgrade current off grid system

[Stove]

Hi all,

The installers I've spoke to said they don't do off gris systems. I am VERY inexperienced with solar, but I can hold my own on most things DIY. Any and all guidance would be greatly appreciated.
Current set up is:
(8) 6 volt, 255Ah @ 100hr trojan batteries
Magna Sine, (2017) Model MS2812 inverter/ charger
3 unknow brand solar panels.
the system has already been upgraded before and some of the unused components are still in the pictures.

I was originally hoping to be able to upgrade the batteries and add more panels, but apparently its not that easy. Since the inverter is from 2017 I was told it would be worth it to replace that as well. So now I'm wondering if I can get newer version of the existing inverter, (12) 12V 200ah lithium batteries and (6) 400-425watt panels. The house doesn’t get a lot of sun (planning on taking down some trees).

 

[green mountain boys]

What are the loads you are going to run with the system?
How long do you need the batteries to supply power when there is no sun?
Do the existing panels face South? 180 degrees? or other?

 

[Stove]

What are the loads you are going to run with the system?
How long do you need the batteries to supply power when there is no sun?
Do the existing panels face South? 180 degrees? or other?

I expect to need 2.2 kWh/ day, but I would like to oversize the system incase needs change in the future. In the late fall/ winter months, this property gets about 4 hours of usable sunlight for the whole day. the existing panels do face south, but the roof has a steep pitch.

 

[green mountain boys]

The steep roof pitch will be good to help shed snow and you are probably near 44 degrees latitude.
If you replace the inverter and solar charge controller I would suggest you consider changing to a 48 volt system. It is more efficient and easier to expand in the future. LiFePO4 batteries should only be charged when they are above 32F so you will have to keep them warm. I would recommend 48 volt batteries instead of putting 12 volt batteries in series to reach 48 volts. Do you have any room for a ground mount? Or do you have to put the panels on the roof?

 

[seneysolar]

Hi all,

The installers I've spoke to said they don't do off gris systems. I am VERY inexperienced with solar, but I can hold my own on most things DIY. Any and all guidance would be greatly appreciated.
Current set up is:
(8) 6 volt, 255Ah @ 100hr trojan batteries
Magna Sine, (2017) Model MS2812 inverter/ charger
3 unknow brand solar panels.
the system has already been upgraded before and some of the unused components are still in the pictures.

I was originally hoping to be able to upgrade the batteries and add more panels, but apparently its not that easy. Since the inverter is from 2017 I was told it would be worth it to replace that as well. So now I'm wondering if I can get newer version of the existing inverter, (12) 12V 200ah lithium batteries and (6) 400-425watt panels. The house doesn’t get a lot of sun (planning on taking down some trees).

Man that inverter is NOT outdated, those are great! Kinda small for a whole house but itll work if you watch loads.

Before you make any upgrade decisions, decide if you really want to stay 12V.

That midnite classic charge controller can probably handle more panels depending on your current panel specs. Best bang for your buck right now would be more solar panels. If you put that charge controller to work at its full potential ( or add another one with your new panels) you may be happy with the rest.

Batteries would be next in line, depending on the age of those. You should have decent storage there already for a 2800w inverter

 

[Stove]

The steep roof pitch will be good to help shed snow and you are probably near 44 degrees latitude.
If you replace the inverter and solar charge controller I would suggest you consider changing to a 48 volt system. It is more efficient and easier to expand in the future. LiFePO4 batteries should only be charged when they are above 32F so you will have to keep them warm. I would recommend 48 volt batteries instead of putting 12 volt batteries in series to reach 48 volts. Do you have any room for a ground mount? Or do you have to put the panels on the roof?

It seems like the 48V systems really are much better. I will most likely be doing the upgrade solo and my biggest concern with this project is making sure it is configured the right way. Is it much more complicated to change to a 48v System? I don't have any usable ground space to mount panels, so going to need to use the roof.

 

[Stove]

Man that inverter is NOT outdated, those are great! Kinda small for a whole house but itll work if you watch loads.

Before you make any upgrade decisions, decide if you really want to stay 12V.

That midnite classic charge controller can probably handle more panels dependingonyour current specs. Best bang for your buck right now would be more solar panels. If you put that charge controller to work at its full potential ( or add another one with your new panels) you may be happy with the rest.

Batteries would be next in line, depending on the age of those. You should have decestorage there for a 2800w inverter

I am not married to a 12v system. Just want to get a reliable system (that can install) that will last for a long time.

 

[green mountain boys]

If your power needs are that modest you could add some panels and keep the 12 volt system you have. You will need to test those batteries to see if they are any good. How long have you been living with the current system? How well is it meeting your needs?

 

[green mountain boys]

A 48 volt system has the same components as a 12 volt system. It is not more complex. 12 volt systems are usually used on small systems.

 

[MisterSandals]

I expect to need 2.2 kWh/ day,

This is a useful number for estimating the array size but the max momentary watts (AC with an inverter?) will guide you to a proper battery voltage and inverter size.

If you're steady at 2.2kWh / 24h = 91.6W around the clock thats a very modest system. If you're running a 2000W microwave to cook or an electric heater periodically, that takes a bit more to get right. And, how much power will be used while the sun is shining and how much at night (when all the power comes from a battery)?

Some answers to these questions will force you to a higher battery voltage.

 

[Stove]

If it isn't more difficult to upgrade to 48v than upgrade 12V system, i will do that. I am trying to keep all solar materials under 10K. Ideally the upgraded system will be able to power a mini split occasionally as well. If I upgrade to a 48V system, could I connect it to the existing solar configuration? The 3 panels I have are probably not adequate for continuous heavy usage, but my thought process is: if I get much more batteries than needed, it will have time to recharge on days its not getting used or I could fully recharge it with a generator if needed occasionally. The cabin may only get used for a day or 2 and then be unused for weeks.

 

[seneysolar]

If it isn't more difficult to upgrade to 48v than upgrade 12V system, i will do that. I am trying to keep all solar materials under 10K. Ideally the upgraded system will be able to power a mini split occasionally as well. If I upgrade to a 48V system, could I connect it to the existing solar configuration? The 3 panels I have are probably not adequate for continuous heavy usage, but my thought process is: if I get much more batteries than needed, it will have time to recharge on days its not getting used or I could fully recharge it with a generator if needed occasionally. The cabin may only get used for a day or 2 and then be unused for weeks.

Indeed if building a complete new system with a $10k budget and you have a minisplit in mind, jumping to 48V makes sense.

Report back with your panel info (label on back of panel) and we can see what those are capable of.

If you're just going to dump your old equipment, ill give you my ups account so you can send it to me

 

[green mountain boys]

The cabin may only get used for a day or 2 and then be unused for weeks.

If you change to LiFePO4 batteries they have to be charged while above 32F. Do you have a plan to keep them warm?

This video might be of some value.

 

[Stove]

I will find out what type of panels are up there now, but probably wont be to till next week.
That video was helpful! So general consensus seems to be that the 48v systems are better than the 12V systems. Do 48v systems not have the same issues in the cold? If I was to build some type of insulated enclosure or store them in a Yeti type cooler in the winter would that be enough? It is could in VT a good part of the year.
I know the 48v batteries are more affordable, can handle a higher "critical load" (not sure if I'm using that correctly) and are typically a better bang for the buck. Are there any other noticeable advantages?
Option 1:
I was to upgrade and keep the 12v system these are the components that were used in the above video:
Victron 12V Quattro-II 3kva 2x120v inverter 120a charger ($1500)
Victron SmartSolar CHarge Controller - there are 15-50A options, not sure which i would need ($200)
Some type of battery monitor, any suggestions? ($100-$300)
(2-4)12V 460Ah LiFePO4 Batteries ($4,000-$8,000)

Option 2: I got a quote for the below system for about $8,000. Thoughts?

 

[seneysolar]

I will find out what type of panels are up there now, but probably wont be to till next week.
That video was helpful! So general consensus seems to be that the 48v systems are better than the 12V systems. Do 48v systems not have the same issues in the cold? If I was to build some type of insulated enclosure or store them in a Yeti type cooler in the winter would that be enough? It is could in VT a good part of the year.
I know the 48v batteries are more affordable, can handle a higher "critical load" (not sure if I'm using that correctly) and are typically a better bang for the buck. Are there any other noticeable advantages?
Option 1:
I was to upgrade and keep the 12v system these are the components that were used in the above video:
Victron 12V Quattro-II 3kva 2x120v inverter 120a charger ($1500)
Victron SmartSolar CHarge Controller - there are 15-50A options, not sure which i would need ($200)
Some type of battery monitor, any suggestions? ($100-$300)
(2-4)12V 460Ah LiFePO4 Batteries ($4,000-$8,000)

Option 2: I got a quote for the below system for about $8,000. Thoughts?
View attachment 195004

48v does not change anything for temperature. Maybe if you were staying with lead acid batteries they would not be discharged as far making themess prone to freezing but in your case thats not an issue.

I dont think i would build a complete new 12v system. You already have one with good components Magnum and Victron are both tier 1 quality.

Im a fan of 24V systems but for your case 48 makes sense for usage.

Ive never worked with Renon but it looks like something that shouldn't be out in the middle of nowhere. Do you really need a 12k inverter???

You might make a good candidate for one of the pre wired panels. Here is an outback system from NAZ electric. Currently on sale too... still needs batteries and panels but otherwise plug and play. Solid choice in my book.

 

[dougbert]

my 1st set of FLA batteries I estimated 7 years before swap out. They made it to 9 years, but I HATED monthly water checks and filling
my 2nd set of 2v FLA I estimated 10 years of life, but I sold them for 1/2 price at 4 years. Again I HATED the monthly water checks

as you stated it was installed in 2017 it has been 7 years now, so those batteries are long in the tooth. The thing about FLA is one should replace ALL the batteries at once so they age together. One should not add new batteries to an old pack.

LiFePO batteries do not have those limitations, just the need to keep above freezing to charge.

 

[hwy17]

Option 2: I got a quote for the below system for about $8,000. Thoughts?

The community will not recommend this. You'll get locked into their system, and a Powerpro is cheaper.

 

[KITROBASKIN]

Why don't you learn on the system you have? Get more panels, planning for a possible update to 48V? Make sure your good quality batteries have water?

 

[seneysolar]

Why don't you learn on the system you have? Get more panels, planning for a possible update to 48V? Make sure your good quality batteries have water?

This would be my first option. He has quality stuff there, probably just neglected batteries. They may come up just fine.

On the subject of water maintenance in lead acids. It is directly related to useage. If its just a weekend getaway; once every spring , summer, and fall would suffice.

The OP seems to want all new stuff and power a minisplit. So he may be disappointed with a 12v setup that requires the user to pay attention and monitor. Overall he will be happier with a 48v setup and he wont have to worry about all that extra money lying around

 

[Stove]

I appreciate all the recommendations. I know I'm all over the place here. What if I left the panels for now, upgraded the charger/ inverter to a newer 48V Magnum charger/ inverter and did 4 of the self heating batteries below. They can charge down to 14 degrees F and discharge down to -4F. My thought process is that I will have much more battery storage than needed, so days I'm not using the cabin will recharge the system after a heavy usage weekend. Then maybe I can add/ upgrade the panels down the road.

48V 100Ah 5.12kWh - Self-Heating Server Rack Lithium Battery

www.epochbatteries.com

Open to all feedback! Thank you!