Off grid cabin powered by solar for 30 years advice needed.

**Mike90250** · 10-06-2016, 12:28 AM

If it's been working for 30 years, it's not broke (except for the dead charge controller)
All I could suggest is next time you replace batteries, use a couple 6V 200ah golf cart batteries wired in series to give you 12V 200ah
If you find yourself running short of power, you could upgrade the PV panel to 200-300W and upgrade the charge controller to a MPPT controller
Morningstar and Midnight solar make some good ones:
http://www.morningstarcorp.com/produ...e-controllers/ Prostar
or http://www.midnitesolar.com/pages/kid/index.php Kid

**3seconds2live** · 10-06-2016, 08:31 AM

Well its not exactly perfect the battery life is pretty short. We arent getting 5 years out of the batteries. Should we have an enclosure for the batteries? Is the cold a problem for them? If i were to upgrade the solar panel do you have a suggestion oh which brand or place to buy them? thanks for the charge controller advice i'll give those a read through.

**organic farmer** · 10-06-2016, 08:42 AM

One of our neighbors has been living off-grid on solar power since the 1980s. His house is all 12vdc. His home stereo is an in-dash car radio mounted in a wall with nice wood trim around it. He has a washing machine and a refrigerator, both of these appliances have individual inverters to power them. His 'charge-controller' is a voltage regulator from a Chevy. His battery-bank is a dozen car batteries wired in parallel. He gets them from a junkyard for the core-charge. Takes them home and tests them. When cars get wrecked most of the time the battery in it is just fine. His entire system is cheap, it is simple, it works, replacements are easy to find.

I believe that once a year, he disconnects all of the batteries. So he can test them individually. Any battery with cells going wonky gets replaced with another junkyard battery.

Living off-grid on solar power does not have to be complicated, nor expensive.

As to your system. If it works be happy. Keep it simple. If you are feeling froggy and want to expand, you certainly can. Since you use your system so rarely. You could amass a huge assortment of batteries, they would have weeks to charge-up. So when you did visit you would have a lot of amp-hours you could use.

**ButchDeal** · 10-06-2016, 08:54 AM

Originally posted by organic farmer

Since you use your system so rarely. You could amass a huge assortment of batteries, they would have weeks to charge-up. So when you did visit you would have a lot of amp-hours you could use.

Again with the uninformed Guess comments as if you know what you are talking about. You can't maintain batteries by trickle charging them constantly.
A large battery bank and small solar simply results in a lots of dead wasted batteries.

**organic farmer** · 10-06-2016, 09:06 AM

Originally posted by 3seconds2live

Well its not exactly perfect the battery life is pretty short. We arent getting 5 years out of the batteries. Should we have an enclosure for the batteries? Is the cold a problem for them? If i were to upgrade the solar panel do you have a suggestion oh which brand or place to buy them? thanks for the charge controller advice i'll give those a read through.

If you were living there fulltime, and cycling the batteries every day [like I do], then you can justify spending more on the system. Expensive batteries are made for daily cycling and they still might only last 10 years. Getting 5 years from your batteries is good.

Cold is a big issue if the batteries are ever discharged. One of my neighbors saw his batteries freeze up and they shattered the casing. It was due to a faucet being left open all night, which ran his well pump, and drained his batteries on a night when we saw -20F temps. If you can keep your batteries charged, then you do not need to be as concerned about the cold temps. Since you will only be cycling your batteries rarely I would not worry about it. We cycle batteries a lot and we get cold temps, so we keep our batteries inside our house [which is pretty common among off-grid homes in our town].

**jflorey2** · 10-06-2016, 11:34 AM

Originally posted by 3seconds2live

With solar advancing so much is it worth using the old panels or buying a single new one.

Most panels last effectively forever. The only things that cause them to fail is:
-PV degradation for amorphous panels (but you probably have crystalline cells which last a lot longer)
-EVA yellowing (with older EVA mixes)
-Water ingress from broken glass
-Corrosion of frame or connectors

If the above does not apply, or you're not seeing much of the above, then you will probably be OK.

Do i have to rewire? My wiring is basically 10 gauge wire through some in line fuses to the charge controller and to the batteries. Should I be caring for the batteries better and what is the best battery for me?

I'd go with two T105 GC2 type batteries in series. They are available and cheap ($100 on sale at Costco.)

An enclosure? I searched the site a bit but i'm not sure if i should be in a different spot or if there is already a thread similar to mine.

Make sure it's weatherproof and vented and that's really all you need. Putting it inside is a bit risky due to hydrogen generation, but with a vented cabin it's not as big a deal. Ideally the enclosure would go inside with a (passive) vent to the outside.

Very low use system needed to power lights and water pump. To replace current system or utilize the current system better?

If it's working keep it; just keep maintaining/changing batteries.
If you want to spend $$ you might consider a better charge controller (3-stage) but it's not critical.

**jflorey2** · 10-06-2016, 11:36 AM

Originally posted by ButchDeal

Again with the uninformed Guess comments as if you know what you are talking about. You can't maintain batteries by trickle charging them constantly.

Well, you can; every IC engine car on the road does that.

A large battery bank and small solar simply results in a lots of dead wasted batteries.

Agreed. But if you are starting with wasted batteries there's no net loss; you start with wasted batteries that need to be recycled and end up with dead wasted batteries that need to be recycled. I wouldn't want to rely on that sort of array for any amount of power, but for someone who is just playing with solar, it's a cheap (and environmentally neutral) way of getting batteries.

**ButchDeal** · 10-06-2016, 11:48 AM

Most IC engines in cars have a voltage regulator in an alternator that does more than trickle charge the battery.

OP isn't "playing" with solar. OP has a 30+ year offsite situation that is wanting to upgrade.

Organic Farmer suggested making "amass a huge assortment of batteries" which would have other problems as well. He gave an anecdotal story of a neighbor that uses junk batteries. Making a huge battery bank of assortments of batteries is going to be detrimental to the newer batteries and possibly dangerous as well, and certainly not going to maintain any kind of charge on it with OPs current 80w array (likely ~60w after 30 years of degradation).

It is a poor suggestion at best with financial implications, and dangerous at worst for anyone to follow said advice.

**SunEagle** · 10-06-2016, 12:18 PM

I have to back up Butch on this. Making a DIY battery bank with minimal panel wattage and a lot of junk batteries ends up with a toxic waste site of acid and lead.

What the OP needs is something like Mike mentioned in post #2. It will not get the OP a long battery life but it will be safer and work for a while.

It does sound like the OP did get pretty good use out of the existing panels that he owns but it may be time to upgrade.

Another option would be for those few occasions you need power. Get a small generator and a battery that can be transported along with a charger. Use the generator for the big loads during the day and charge the battery for the small loads at night. Take it all with you when you go.

**jflorey2** · 10-06-2016, 12:28 PM

Originally posted by SunEagle

I have to back up Butch on this. Making a DIY battery bank with minimal panel wattage and a lot of junk batteries ends up with a toxic waste site of acid and lead.

No more so than the toxic waste site of acid and lead you'd find at the dump. (And the batteries in his site will more likely be recycled.) I've done what OF described right after college when I first started working with solar, and it worked OK. I learned quite a bit, then moved on to better battery/solar systems.

What the OP needs is something like Mike mentioned in post #2. It will not get the OP a long battery life but it will be safer and work for a while.

Agreed; that's a better choice for reliability.

**ButchDeal** · 10-06-2016, 12:37 PM

Originally posted by jflorey2

No more so than the toxic waste site of acid and lead you'd find at the dump. (And the batteries in his site will more likely be recycled.) I've done what OF described right after college when I first started working with solar, and it worked OK. I learned quite a bit, then moved on to better battery/solar systems.

Agreed; that's a better choice for reliability.

OP is not trying to play around or learn. He wants a useful system upgrade path for a 30 year system

there should be no lead acid batteries in the dump, they are easily recycled and nearly all dumps have collection points for them. Further any place that sells batteries is supposed to take the old ones back for recycling and even pay for them.

I really can't believe that you are doubling down on this. the large mis matched battery bank has problems in and of itself, and can be dangerous. Through in constant undercharging and you have a real disaster, with possible explosion if one battery melts down and shorts.

Mikes comment (post 2) is best and safest option. Toss in an upgraded module and CC and OP has a nice SAFE system for years.

**Logan5** · 10-06-2016, 05:17 PM

running 12v over any distance to then step up for use, defies logic. I imagine an old house with huge AWG 000 cable that you have to step over to cross the hoard of junk batteries . Like Green Acres on steroids.

**organic farmer** · 10-06-2016, 06:50 PM

I can not imagine anyone's home with welding cable left strung around for anyone to trip over.

This forum [Solar Panel Talk] is for solar power, this sub-forum [ Off-Grid Solar] I assume is focusing on off-grid applications of solar power. So I would think that most of us here are off-grid, and that we generally all live in regions where we all have many off-grid neighbors. I certainly do.

Within the greater off-grid community, many people have been living off-grid for years and even decades.

It does not seem logical that many of them have all of the latest, most modern and expensive systems powering their homes.

What is the reason for all of this snobbery ?

**solar pete** · 10-06-2016, 10:30 PM

Hi All, just thought I would throw in my 2 cents worth, organic farmer just relax, I dont think its snobbery at all I think its about people here wanting to promote SAFE options for people. We all know its possible to cobble together a system that may work using cheap, second hand, or not fit for purpose parts, but we dont want to promote that here as it is generally dangerous, thats all.

Off grid cabin powered by solar for 30 years advice needed.

Off grid cabin powered by solar for 30 years advice needed.

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