feedback: this forum has convinced me not to build a solar system.

[Brucey]

Well doesn't look promising

View attachment 228029

224 watts tar load on long cold Maine winters could easily make the SOC 0%. If one is going to do this the only real option is indoors for the electronics and batteries.

What worries me is it turns on the heater at freezing. That's based on one or more temp sensors located on the exterior of the batteries. Once those sensors come up to 41F the heater turns off. But the core of the cell could well still be at freezing temps.

 

[SparkyJJO]

What worries me is it turns on the heater at freezing. That's based on one or more temp sensors located on the exterior of the batteries. Once those sensors come up to 41F the heater turns off. But the core of the cell could well still be at freezing temps.

Well the exterior would hit freezing before the core of the cell, so logically if the heaters came on at an exterior temp of 0C the interior temp would never reach that low.

 

[Hedges]

The question is how many watts per degree C delta leaks out.
Does it consume 224W constantly? Or only 10% of the time at your ambient temperature?

No insulation, correct? So wrapping it in insulation could help. When cold.

 

[thomBangor]

It is curious to me that there are voices saying this battery could never cause a fire (too hot?), but also saying it could never be trusted not to get too cold. Seems somewhat contradictory that one could be true without the other.

 

[Brucey]

It is curious to me that there are voices saying this battery could never cause a fire (too hot?), but also saying it could never be trusted not to get too cold. Seems somewhat contradictory that one could be true without the other.

They can get cold and still discharge. You just can't charge them below freezing (traditional LFP) without potential damage. Even at 5 degrees C they are limited in terms of current , need to get them up to about 15-20C I believe to get into the sweet spot where the battery could potentially accept a charge rate of 1C for example.

 

[Quattrohead]

Consider using the 18kpv.....why ?
1. It looks like it could power your whole house.
2. It can replace the ATS as that is built in.
3. It can recharge your batteries automagically if they get too low, do away with the generator ???
4. It will bypass so your house runs on grid on overload. (good luck overloading it, I did once in my all electric house in Florida)
5. Wiring it in is so easy compared to everything else.

 

[thomBangor]

Consider using the 18kpv.....why ?
1. It looks like it could power your whole house.
2. It can replace the ATS as that is built in.
3. It can recharge your batteries automagically if they get too low, do away with the generator ???
4. It will bypass so your house runs on grid on overload. (good luck overloading it, I did once in my all electric house in Florida)
5. Wiring it in is so easy compared to everything else.

Yeah I'd love to, but that thing is $5000. Even the 12kPv is $3500. If EG4 got that 12kPv price even in the ballpark of the 6000xp, I would already have it on my bill of materials.

 

[thomBangor]

The question is how many watts per degree C delta leaks out.
Does it consume 224W constantly? Or only 10% of the time at your ambient temperature?

No insulation, correct? So wrapping it in insulation could help. When cold.

Yes I think this is the crux of the matter. Since I can't put batteries indoors, I might be the first one to find out the answer I suppose.

 

[Brucey]

Yes I think this is the crux of the matter. Since I can't put batteries indoors, I might be the first one to find out the answer I suppose.

Might be a market for outdoor battery blankets/cozies like you can get for hot water heaters. at least then there’ll be some chance of keeping some heat within the metal enclosure.

 

[Solar Guppy]

Yeah I'd love to, but that thing is $5000. Even the 12kPv is $3500. If EG4 got that 12kPv price even in the ballpark of the 6000xp, I would already have it on my bill of materials.

You need to recalibrate your cost expectations. The right equipment costs what it costs. This with your insistence it "must" be outdoors will end in failure and then your out whatever the price is of what you cobble together, Do it once, Do it right or move on to something else to due with your time.

 

[thomBangor]

You need to recalibrate your cost expectations. The right equipment costs what it costs. This with your insistence it "must" be outdoors will end in failure and then your out whatever the price is of what you cobble together, Do it once, Do it right or move on to something else to due with your time.

You need to be more specific please. You have made many blanket statements without supporting evidence.

Earlier you said solar can never achieve ROI in cold weather, but did not explain your statement nor provide evidence.

In this thread you are saying that the equipment I have put into the bill of materials is not 'right', but you do not explain your statement nor provide evidence.

You also state with certainty and without flexibility that use of an outdoor-design battery pack will end in failure if used outdoors, but you do not explain your statement nor provide evidence.

Constructive criticism with analysis is welcomed and encouraged, but unsupported negativity for its own sake is something I would discourage. Please try to add supporting data to your criticisms in the future.

I think there are some valid criticisms of my approach. Here are two that concern me in particular:
1. System runs out of power- batteries get cold/damaged
2. Maine does have one or two days/year that are below the minimum temp spec (-4 deg F)

To mitigate #1 I need to watch the battery temp carefully during the first winter, and compare it to the heat energy used (tar??) and the minimum daily solar input (clouds/snow/etc). Then I need to project those numbers into a worst case scenario and make a decision about whether I need further mitigation, or the system is self-life-sustaining. If all else fails I will run another grid power line from my panelbox to the garage and use that to heat and/or charge the battery all winter.

 

[thomBangor]

Might be a market for outdoor battery blankets/cozies like you can get for hot water heaters. at least then there’ll be some chance of keeping some heat within the metal enclosure.

Yes there are number of posts about using pet heating pads on a temperature triggered relay (e.g. inkbird) to warm a battery pack inside an insulated box.

related references:

EG4 PowerPro batteries out doors in cold weather any issues?

Anyone have there EG4 Power Pro batteries installed outside your home and are experiencing extremely cold weather? Wondering if you are having issues. Personally I would never put them outside even though they are rated for it. It's freezing outside my house for the past two days but I have my...

diysolarforum.com

https://www.amazon.com/gp/product/B09YLWTLPP/ref=ox_sc_saved_title_1?smid=A2ANGXXNWZBXLF&psc=1

https://www.amazon.com/gp/product/B01HXM5UAC/ref=ox_sc_saved_title_1?smid=A1RUFFFCQ74BCW&th=1

 

[1201]

Yeah I'd love to, but that thing is $5000. Even the 12kPv is $3500. If EG4 got that 12kPv price even in the ballpark of the 6000xp, I would already have it on my bill of materials.

I would urge you to consider

1. Srne 10kw instead of eg4 6kw. Same price almost double the power.

2. If you want to save money diy your 280ah battery for about 60% of what a powerpro costs.

 

[Brucey]

Yes there are number of posts about using pet heating pads on a temperature triggered relay (e.g. inkbird) to warm a battery pack inside an insulated box.

related references:

EG4 PowerPro batteries out doors in cold weather any issues?

Anyone have there EG4 Power Pro batteries installed outside your home and are experiencing extremely cold weather? Wondering if you are having issues. Personally I would never put them outside even though they are rated for it. It's freezing outside my house for the past two days but I have my...

diysolarforum.com

https://www.amazon.com/gp/product/B09YLWTLPP/ref=ox_sc_saved_title_1?smid=A2ANGXXNWZBXLF&psc=1

https://www.amazon.com/gp/product/B01HXM5UAC/ref=ox_sc_saved_title_1?smid=A1RUFFFCQ74BCW&th=1

Yes the insulated box is a proven method. Keeping the cold from ever contacting the cells.

 

[thomBangor]

I would urge you to consider

1. Srne 10kw instead of eg4 6kw. Same price almost double the power.

2. If you want to save money diy your 280ah battery for about 60% of what a powerpro costs.

Thanks, I saw your mention of the Srne 10kW. I looked at it, but since this is my first go at a home solar installation, it makes me nervous to use parts I'm unfamiliar with. Is there a big community of Srne supporters I should look into? I like the 6000xp because it seems to be extensively used/tested and there is a lot of information available as a result.

I appreciate the suggestion, but I am not going to DIY my batteries. If I go down that rabbit hole I will want to make my batteries better than EG4's, and that will take so so so much of my time. Might be worth doing after I've completed this first install, but in this go-round I want to use well-established off-the-shelf parts.

If there is a case to be made that I really need the 12kPv, then I'd enjoy hearing/reading it. Until that time, I don't see the extra $2000 price as being necessary right now. Maybe when the surge capacity is too small to start my well pump I'll change my mind

 

[Brucey]

If I go down that rabbit hole I will want to make my batteries better than EG4's, and that will take so so so much of my time. Might be worth doing after I've completed this first install, but in this go-round I want to use well-established off-the-shelf parts.

That won't be hard as long as you use a BMS with active balancing versus their passive BMS designs.

 

[thomBangor]

Yes the insulated box is a proven method. Keeping the cold from ever contacting the cells.

Interestingly there is a guy in that thread who mentions using a water-heater-insulation-blanket to insulate his. Easy to apply and remove.

I am hoping to find a prefab outdoor mini shed that this will fit inside, and then add insulation. I like rockwool because it is ridgid, non-conductive, fire-proof, and mold resistant. Might also consider ridgid polystyrene because it is ridgid and wind-proof.

I'm aware the unit weighs 300 lbs. I would modify the mini-shed to fit around it.

e.g. https://www.walmart.com/ip/Keter-St...2593972074&athposb=0&athena=true&athbdg=L1103

 

[Brucey]

Interestingly there is a guy in that thread who mentions using a water-heater-insulation-blanket to insulate his. Easy to apply and remove.

I am hoping to find a prefab outdoor mini shed that this will fit inside, and then add insulation. I like rockwool because it is ridgid, non-conductive, fire-proof, and mold resistant. Might also consider ridgid polystyrene because it is ridgid and wind-proof.

e.g. https://www.walmart.com/ip/Keter-St...2593972074&athposb=0&athena=true&athbdg=L1103

At least that'll keep the wind off it etc. And then bring the DC cables back into the house for the inverter? Now one of the things you could do is out the 6000xp in there as well, it's idle util will warm that shed up. Plus seperate you from the noisy fans when it's under reasonable load.

 

[thomBangor]

At least that'll keep the wind off it etc. And then bring the DC cables back into the house for the inverter? Now one of the things you could do is out the 6000xp in there as well, it's idle util will warm that shed up. Plus seperate you from the noisy fans when it's under reasonable load.

Great idea. I was going to mount the 6000xp on the indoor side of that wall, because they list the 6000xp weatherproofing as zero (which bums me out). The inside of my garage is constantly full of flying sawdust etc so I wasn't thrilled about that. But, inside that box it is shielded from almost all of the weather, and shares heat with the nearby battery! love it

 

[1201]

Thanks, I saw your mention of the Srne 10kW. I looked at it, but since this is my first go at a home solar installation, it makes me nervous to use parts I'm unfamiliar with. Is there a big community of Srne supporters I should look into? I like the 6000xp because it seems to be extensively used/tested and there is a lot of information available as a result.

There are several users on here who have had good luck with srne inverters. A 10kw is going to give you a lot more headroom for adding loads.

I appreciate the suggestion, but I am not going to DIY my batteries. If I go down that rabbit hole I will want to make my batteries better than EG4's, and that will take so so so much of my time. Might be worth doing after I've completed this first install, but in this go-round I want to use well-established off-the-shelf parts.

I thought you were looking for a short roi? I'm not sure why one would buy a battery for $3600 that could be diyed for $2200.

If there is a case to be made that I really need the 12kPv, then I'd enjoy hearing/reading it. Until that time, I don't see the extra $2000 price as being necessary right now. Maybe when the surge capacity is too small to start my well pump I'll change my mind

There is no case to be made for a 12k pv and if you were considering that then the better choice imo would be the growatt sph10000tl-hu-us

 

[SparkyJJO]

I would urge you to consider

1. Srne 10kw instead of eg4 6kw. Same price almost double the power.

2. If you want to save money diy your 280ah battery for about 60% of what a powerpro costs.

Just be aware DIY battery is a lot more work.

Full disclosure: I am an avid DIYer, to my own detriment sometimes. But it is rewarding WHEN it works (which is most of the time, just usually not on my ideal timescale). If you want it NOW, buy it pre-built, and expect to pay for it. If you have the time on your hands and want to learn, DIY is awesome. Just be willing to put the effort and time into it. I didn't think DIY'ing a battery pack would take me as long as it has. But I have 3 kids 5 and under, so, yeah, I don't have a lot of free time either

 

[Brucey]

Great idea. I was going to mount the 6000xp on the indoor side of that wall, because they list the 6000xp weatherproofing as zero (which bums me out). The inside of my garage is constantly full of flying sawdust etc so I wasn't thrilled about that. But, inside that box it is shielded from almost all of the weather, and shares heat with the nearby battery! love it

Maybe something like this for venting the heat of the 6000xp in the warmer months:

https://www.amazon.com/AC-Infinity-AIRLIFT-T10-Temperature/dp/B07T75SS7V

 

[thomBangor]

There are several users on here who have had good luck with srne inverters. A 10kw is going to give you a lot more headroom for adding loads.

Ok I'll look deeper into it. Is there a particular model number you're referring to? Any idea if it is capable of passing a generator through, and/or charging the batteries using grid power?

As for short ROI- yes, but I'm willing to give up $1400 extra for a battery pack that is purpose built with everything nicely tucked inside. I'm a very paranoid person, especially about high-current wiring (due to a previous career of mine). Every exposed wire/terminal I see is another nightmare I have about arc, visitors who get injured due to ignorance, father-in-laws accidentally putting a shovel across battery terminals, etc. The $1400 buys me both peace of mind, and many hours back in not having to build it myself, and then build a shell for it myself, and then build a bracket for the shell myself, and on and on.

 

[thomBangor]

Just be aware DIY battery is a lot more work.

Full disclosure: I am an avid DIYer, to my own detriment sometimes. But it is rewarding WHEN it works (which is most of the time, just usually not on my ideal timescale). If you want it NOW, buy it pre-built, and expect to pay for it. If you have the time on your hands and want to learn, DIY is awesome. Just be willing to put the effort and time into it. I didn't think DIY'ing a battery pack would take me as long as it has. But I have 3 kids 5 and under, so, yeah, I don't have a lot of free time either

Winter starts Nov 1 here, so I need to get the thing together pretty quick. I love DIY too, but the scale of this project demands some $ exchanged for expediency. Also if I tell my wife I DIY'd the batteries she is going to get upset.

 

[Quattrohead]

This thread is the perfect example of why the perfect decision is not a 5-minute thing. I and I'm sure many others have nickel and dimed ourselves silly before we've ended up with the appropriate system. $1000 ats, $150 shed, couple hundred bucks of insulation, 100 or 2 in heating doodads, long heavy duty battery cables, you get the idea.
I suggested the 18K PV because it is by far the easiest to handle as far as wiring goes, there are acres of room and ginormous connectors. The 12K PV is somewhat lacking in that department but not as bad as a 6000XP. However even those are perfectly fine as long as you consider the wiring box.
Don't be discouraged, some of our suggestions seem a little harsh but they are from the heart because we have been there, done that, buggered it up the first time and eventually got it right.
And please, battery inside where it was designed and made to be. Honestly your lawn mower is more dangerous.