Off grid cottage; sol-ark15k

[Asnarby]

Hey,

I’ve been reading up as much as I can on this forum and decided to go overkill with a Sol-Ark 15k for my cottage in Nova Scotia.

What I have to install;
-7kW of solar
- two strings of DC solar to Sol-ark
- 8x 230 amp 12V agm batteries

Electrical loads I currently have;
-115V /220V 1/2 HP shallow well pump (from lake). It is currently wired as 115V to the breaker panel. Stamped on the pump is 8.2 / 4.1 amps.
- lights that I need to switch over to LED
- dish washer
- clothes washer

Things I need to add;
- Starlink internet and wifi router
- security system with 4-5 cameras
- French door fridge/ freezer
- 115V, 9,000 BTU senville mini split.

In the future I’d like to add (and likely only run these when the batteries are full and I have excess power)
- 220V senville 24,000BTU mini split
- hot water heater (currently direct propane which I will still keep )

The last two future additions are a ways out, however I’m curious what rate I can charge my batteries safely and for good longevity, and if that setpoint on the all-ark will cause any issues with the surges I get when the well pump or mini split first cut in. Will I need soft starts?

I also need to decide if I should install the Sol-ark outside in a she near the electrical panel or in the utility room ( door to enter it is in our master bedroom, I’m worried about noise)

Any assistance is greatly appreciated!

Best regards,
Andreas

 

[Nobodybusiness]

Electrical loads I currently have;
-115V /220V 1/2 HP shallow well pump (from lake). It is currently wired as 115V to the breaker panel. Stamped on the pump is 8.2 / 4.1 amps.
- lights that I need to switch over to LED
- dish washer
- clothes washer

Could convert the well to 240 and lower your amperage.

The 15kw isn’t silent but it’s not noisy either.
I have mine mounted in another building but not because of noise.

I would say the 15k will have no problem with these small loads.

Can’t speak to to the AGMs as I do not know the charge/discharge profile.

I’m sure someone on here will help you with that.

 

[robby]

Hey,

I’ve been reading up as much as I can on this forum and decided to go overkill with a Sol-Ark 15k for my cottage in Nova Scotia.

Overkill on the Inverter alone is not going to make things successful. You also need Panels and Batteries to match it's capabilities.

What I have to install;
-7kW of solar
- two strings of DC solar to Sol-ark

One of the first things you need to do is find out how much power those panels will produce at your location. This calculator will do that for you and is pretty accurate.
https://pvwatts.nrel.gov/

- 8x 230 amp 12V agm batteries

Why AGM batteries, Your off grid and will need something that can cycle daily and do it for many years.
You should be looking at LFP batteries, not AGM.
Something like this and maybe six of them :
SOK Batteries

Electrical loads I currently have;
-115V /220V 1/2 HP shallow well pump (from lake). It is currently wired as 115V to the breaker panel. Stamped on the pump is 8.2 / 4.1 amps.
- lights that I need to switch over to LED
- dish washer
- clothes washer

Things I need to add;
- Starlink internet and wifi router
- security system with 4-5 cameras
- French door fridge/ freezer
- 115V, 9,000 BTU senville mini split.

This load is easily managed by a 15K along with the 24,000 BTU AC.

In the future I’d like to add (and likely only run these when the batteries are full and I have excess power)
- 220V senville 24,000BTU mini split
- hot water heater (currently direct propane which I will still keep )

The last two future additions are a ways out, however I’m curious what rate I can charge my batteries safely and for good longevity, and if that setpoint on the all-ark will cause any issues with the surges I get when the well pump or mini split first cut in. Will I need soft starts?

Your pump does not seem to draw all that much power so I would not worry about it.

I also need to decide if I should install the Sol-ark outside in a she near the electrical panel or in the utility room ( door to enter it is in our master bedroom, I’m worried about noise)

Sol-Ark is not that noisy but I have no idea how close it will be to you bedroom

Any assistance is greatly appreciated!

Best regards,
Andreas

This would be a better setup with LFP batteries and double the amount of panels.

 

[Asnarby]

Th

Overkill on the Inverter alone is not going to make things successful. You also need Panels and Batteries to match it's capabilities.

One of the first things you need to do is find out how much power those panels will produce at your location. This calculator will do that for you and is pretty accurate.
https://pvwatts.nrel.gov/



Why AGM batteries, Your off grid and will need something that can cycle daily and do it for many years.
You should be looking at LFP batteries, not AGM.
Something like this and maybe six of them :
SOK Batteries


This load is easily managed by a 15K along with the 24,000 BTU AC.



Your pump does not seem to draw all that much power so I would not worry about it.

Sol-Ark is not that noisy but I have no idea how close it will be to you bedroom

This would be a better setup with LFP batteries and double the amount of panels.

Thanks for the input. I’ll reply to both of you here. I do plan to change to lithium batteries in the future, but at the moment I was able to get the AGM for $0. Can’t pass that up. We wanted to spend a summer there and see how things work and what our energy needs are. We will switch to Lithium batteries when these guys are shot though.

The amount of panels we have out there I thought was overkill for our needs as well. We have very little power needs at the moment, and the idea was when the sun is really hot, our air conditioning can run. The main times we’ll be out there is when we have nice summer weather.

Great news on well pump and air conditioning.

With the loads mentioned above and situation, what would you set the Sol-ark charge rate at?

I’m thinking I may be better off having the inverter and batteries in a small insulated shed that I can open on both sides for airflow in summer, but maybe have a small heater in it for winter. This would also likely be best for the lithium batteries when they are swapped in.

Thanks again for the assistance!
Andreas

 

[robby]

That makes sense with the Batteries, you cannot beat free.
I assume your house is located in Nova Scotia.
You need to run the pvwatts software that I linked. It will tell you how much power to expect each month of the year.
I suspect that with 7KW of panels, Winter is going to be very rough.

 

[Asnarby]

That makes sense with the Batteries, you cannot beat free.
I assume your house is located in Nova Scotia.
You need to run the pvwatts software that I linked. It will tell you how much power to expect each month of the year.
I suspect that with 7KW of panels, Winter is going to be very rough.

All good in winter, it’ll be used a bit in the fall but it is mainly a summer spot. I have a generator and will also heat with wood if I spend time out there in low sun seasons.

Thanks for the tips!

 

[SamDeleted]

- 8x 230 amp 12V agm batteries

Those AGM are 1.83kwh each . Multiply by 8 makes 14.7kwh

If you want them to last you should only take them down to 50%soc so 7.35kwh useable capacity. ( You can go lower with AGM, all the way down to 20% but it will degrade the battery a lot faster)


Edit: 2,760 each , 22kwh total, 11kwh useable!

Is 7.5 kWh enough for what you're doing? Will that see you threw the nights, what about if it's a grey low production day after a long night


I actually have a very similar sized AGM system running right now, 15kwh (7.5 useable) it gets down to about 55%soc over night, and then it's back up to 100% about 3pm on a sunny day , but grey days can set us back . I'm planning on upping capacity to 25kwh

 

[Asnarby]

J

All good in winter, it’ll be used a bit in the fall but it is mainly a summer spot. I have a generator and will also heat with wood if I spend time out there in low sun seasons.

Thanks for the tips! Just hoping to have enough power to run the internet and cameras so hopefully I’ll be ok!

 

[Asnarby]

Those AGM are 1.83kwh each . Multiply by 8 makes 14.7kwh

If you want them to last you should only take them down to 50%soc so 7.35kwh useable capacity. ( You can go lower with AGM, all the way down to 20% but it will degrade the battery a lot faster)


Is 7.5 kWh enough for what you're doing? Will that see you threw the nights, what about if it's a grey low production day after a long night


I actually have a very similar sized AGM system running right now, 15kwh (7.5 useable) it gets down to about 55%soc over night, and then it's back up to 100% about 3pm on a sunny day , but grey days can set us back . I'm planning on upping capacity to 25kwh

Hey, I thought I had more capacity than that but must be doing my calculation wrong. I thought it was 230x 12 for 2.76kW.

When we are at the cottage, I expect night time consumption to be just some lights, well pump for the toilets, and running the internet. Cameras will be off when we’re out there.

More storage would be great, but hopefully this will make do for this summer.

The air conditioner we’ll run in the daytime, and if it’s brutally hot we’ll have the generator come on at night to top up the batteries and run it as well.

I do need to add a sizeable pressure tank I think so the pump doesn’t have to cut in so often.

 

[SamDeleted]

Hey, I thought I had more capacity than that but must be doing my calculation wrong. I thought it was 230x 12 for 2.76kW.

Yes sorry lol it was 5am here, you are correct

2,760 each , 22kwh total, 11kwh useable!

That should be plenty

 

[SamDeleted]

Have you got a link to the battery specs ? It's possible that 240 is the c10 aswell , when in reality you're probably better off looking at the c20 , maybe around 270 amps ?

 

[Asnarby]

Have you got a link to the battery specs ? It's possible that 240 is the c10 aswell , when in reality you're probably better off looking at the c20 , maybe around 270 amps ?

Hopefully that’s the case! I checked them all and theyre all around the exact same voltage for when I connect them.

I’m waiting for my wife to send a picture of the label. I’m currently at sea in the Arctic.

Thanks again for the help!

 

[Asnarby]

Sorry the o

Have you got a link to the battery specs ? It's possible that 240 is the c10 aswell , when in reality you're probably better off looking at the c20 , maybe around 270 amps ?

Sorry the picture is a bit blurry.

 

[SamDeleted]

Sorry the o

Sorry the picture is a bit blurry.

Trojan traction batteries, very cool, expensive

Bet they are heavy!

 

[Asnarby]

Trojan traction batteries, very cool, expensive

Bet they are heavy!

They’re definitely heavy! Any insight on the batteries themselves? What would you limit charge amperage to from the Sol-ark?

Thanks,
Andreas

 

[Asnarby]

It says not to install or charge batteries in unventilated area. What would you suggest for winter time in a shed, how much air circulation would be adequate?

I didn’t see anything on charge rate, but from what I’ve read, 15% of total amps (20hr) so 69/70 amps for 48V? Does that sound right? The sol ark 15k is set at 275 amps so I’ll have to dial that way back.

Please let me know if I’m off on any of this.

Cheers,
Andreas

 

[SamDeleted]

They’re definitely heavy! Any insight on the batteries themselves? What would you limit charge amperage to from the Sol-ark?

Thanks,
Andreas

Data sheet says 20% of the c20 rating (230ah) = 46 amps

8 x 46amps = 368amps(4.4kw) max charge rate ... but that's at 12v

Wired for 48v max charge rate should by mu maths be 91amps (4.4kw)


Manuals:

Trojan 8D AGM Deep Cycle Battery 8D-AGM

8D-AGM Trojan 12V Deep Cycle AGM Battery Trojan Batteries was founded in 1925 and has become one of the world's leading manufacturer of deep-cycle, Solar and motive batteries. Trojan produces a broad range of energy storage solutions including deep-cycle Flooded, AGM, Gel and Lithium batteries...

www.tayna.co.uk

 

[Asnarby]

Data sheet says 20% of the c20 rating (230ah) = 46 amps

8 x 46amps = 368amps(4.4kw) max charge rate ... but that's at 12v

Wired for 48v max charge rate should by mu maths be 91amps (4.4kw)

View attachment 152189
Manuals:

Trojan 8D AGM Deep Cycle Battery 8D-AGM

8D-AGM Trojan 12V Deep Cycle AGM Battery Trojan Batteries was founded in 1925 and has become one of the world's leading manufacturer of deep-cycle, Solar and motive batteries. Trojan produces a broad range of energy storage solutions including deep-cycle Flooded, AGM, Gel and Lithium batteries...

www.tayna.co.uk

Thanks! I just found something online saying 20% of C20 so that’s a plus. Is charging at the maximum any detriment to the longevity of the battery though? Should I dial it back at all?

Thanks,
Andreas

 

[SamDeleted]

It says not to install or charge batteries in unventilated area. What would you suggest for winter time in a shed, how much air circulation would be adequate?

it's mostly talking about locking them in a sealed cabinet

Since they are sealed batteries so they don't gas all the time , everything is meant to stay inside . but if something goes wrong they do have a vent on the top. Battery gases can be explosive in the right condition so you don't want a build up of them


Really depends on how well your sheds built I guess , if it's as breezy as my is shed it's fine lol, if your worried stick a vent in


I'd be more concerned about the cold, although AGM are your best bet for cold weather, you shouldn't really charge / discharge below freezing (0c/32f?). They are pretty tough to cold storage

 

[SamDeleted]

Thanks! I just found something online saying 20% of C20 so that’s a plus. Is charging at the maximum any detriment to the longevity of the battery though? Should I dial it back at all?

Thanks,
Andreas

Actually charging too slow can be even more of an issue , they are folklift / motive power / traction batteries, designed to take abuse,

heavy deep discharges working all day, and then get stuck on a big fast workshop over night, to do it all again tomorrow....they are good batteries & should serve you well



But saying all that, I'd give a little margin from the absolute top figure . Maybe I'm just over cautious

Careful with the charge voltage, AGM batteries are sensitive to that , too higher voltage you can boil the battery, it will gas out its vents , and with it being a sealed lead acid, once it's gone it's gone . You'll loose capacity

Stick to the number on the data sheet , maybe lower , listen to the battery you don't want much bubbling noises . A little bit is ok