New Member with an Off-Grid Cabin (solar newbie)

[Logan005]

Don't regret joining SPT, There is no easy way to tell someone they have made a huge and expensive mistake. learning this is painful, but it is the learning curve of many, you are not alone. Listen and learn.

[Sunking]

I agree that the OP's battery is way too big for his panel wattage and CC. He might be able to salvage his system if he can get the correct CC and reduce his battery system in half to about 900Ah. The problem I feel is that most of his batteries may already be nothing but boat anchors after being majorly discharged.

The big issue is what will his true daily watt hour use be and does he have enough panel wattage to charge the matching battery. If not and he ends up needing an 1800Ah battery then going to a 24v or 48v battery would be his best option.

Yes I know, but everything is incompatible. It started when he bought something and hoped it worked, rather than take the time and research what was needed to acheive his goal. Like so many come here and wonder why it failed.

1 Determine daily Watt Hours. Do not go until until you determine Daily Watt Hours
2. Determine location worse case Sun Hours.
3. Design System.
4. Get over Sticker Shock, it is expensive to do right, and even more expensive if you get it wrong.

Yes he says he regrets coming here. His regret is he did not do any research and does not like hearing the truth. He screwed up before he ordered equipment.

His battery can support up to 4.3 Kwh per day. Judging from his use of language suggest he is in the UK somewhere. If he had looked up his worse case Sun Hours of less than 2, he would have known the panel wattage would need to be 3000 to 4000 watts. 1000 watts is not even remotely close, 2000 to 4000 watts requires a 48 volt battery, and 40 to 80 amp controller. Now he regrets coming here to find out how badly he screwed up and complaining? Not our fault he claimed to be smart and did no research.

He now has a brand new 500 Kg Boat Anchor of batteries he spent a fortune on. Bet he does not like to hear that either. With his location (UK), even with half the batteries, 1000 watts will still not be enough to charge the batteries.

[a Cuppa Coffee]

I am in the US, state of West Virginia. I have found Guest to be very helpful. There are very few things that can't be fixed. I am in a situation where I have sold my old house and am building this one (and my solar system) from the profits of that sale. My batteries seem fine. They were brand new, and only online 3 days before I caught the problem. There was barely anything being used off of them...a couple of LED lights, I made about a pot of coffee a day while I was out there building things outside the cabin. I was not running any large tools off of them.

If I need to replace a battery or two, I will. My only major regret is that you Guest seem to have latched onto this post and keep replying with gloom and doom.

I have an 80Amp CC arriving tomorrow. It will work itself out. I'll work it out.

[Sunking]

Do you have a 4 Kwh generator with a high power battery charger. It is a must have item for off-grid.

[a Cuppa Coffee]

Yes. We have a 10kw and a 2.5kw generator as well as a sturdy battery charger. Like I said before, we have a horrid excuse for an electric company. Power outages constantly.

[Sunking]

Everyone is telling you the same thing. You brought this on yourself because you said you were SMART. Well smart people do research and test the waters before they dive in head first. You did everything you could have possible done wrong, and putting your life in danger. No one has the guts to tell you that. We could have saved yourself thousands of dollars with research. What you have is not workable, plain, and simple. You have to loose half your batteries or double your panel wattage. You have no clue how much danger you have put yourself in operating 12 volts at 1000 watt power level. At a minimum you should be operating at 24 volts and even better at 48 volts. If you had done your research you would already know that. You will also learn going off-grid is going to be real expensive. Sun Eagle is telling you the same thing, just sugar coated. I have no use for PC, makes liars out of people. You screwed up and you own it.

[a Cuppa Coffee]

I have not blamed anyone here for my problems. I screwed up, I get that. I'll fix it. As for our interactions, there's a difference between political correctness and being polite. People who have no time for political correctness typically use that as an excuse to be jerkish to people. You're correct, SunEagle also told me I made a mistake, but gave me suggestions as to how I can fix it without throwing the baby out with the bath water...and without phrasing every comeback/reply equivalent to running one's knuckles across a vegetable grater. You may know your stuff regarding Solar (I don't know, this is the internet...you could be anyone), but your expertise would be better received if you weren't so rude.

[a Cuppa Coffee]

Furthermore, there's many different kinds of SMART. Though you'll likely reply with rudeness, I have a very high IQ. I have a Masters Degree...of which I graduated with a 4.0 (Perfect marks all semesters if you're not from the US. After all, without looking at my profile you thought I was apparently a Brit.). That said, it's a Masters in Teaching Social Studies as well as Sociology. I assume with you're tag on your posts that you're an Electrical Engineer. Different kinds of SMART. My father that helped me with my system is a retired Electrical Worker with over 30 years experience. He's also smart at what he does, but he worked with High Voltage and Public A/C electrical systems...so DC is not necessarily his forte.

I have reasons for being off-grid and attempting self-reliance. Not that you care, but I have a handful of rare Neuromuscular, as well as, headache disorders. Being out in the mountains, attempting a minimalist peaceful life makes daily life less painful. Because of damage to the myelin sheathing around my nerves, being around high voltage A/C or even many residential power lines, even things as simple as fluorescent lights makes my ever-present head and nerve pain much worse. I have to have multiple MRIs per year to track my illnesses and their progressions. I have to be put to sleep to have MRIs as they cause horrid pain. We have very few electrical appliances in our new house. I have around $5000 US in my 960 watt system as it is, if I can salvage it even at the 80amp CC and only 900ah of my batteries (6V in series parallel) the approx 2700wh calculation that Guest gave me...it should run what we have.

[Logan005]

"My only major regret is that you Sunking seem to have latched onto this post and keep replying with gloom and doom."

I am amazed SK replied at all. You are lucky he took the time to offer guidance. I consider his and a few others advice expert.

You mention an electric coffee maker, Are you aware how much power an electric drip coffee pot uses. a 5 min. perk at 900 to 1500 watt's, then however long you leave it on the 300 watt burner. consider making coffee on a gas stove or camp fire or wood stove. If you insist on electric, get a unit that includes an insulated carafe, not one that uses a glass pot and an electric burner.

I hope your batteries are all still ok, but you need to get them fully charged and do load and hydrometer test to be sure. don't forget your battery bank is way over sized to your array, so in the mean time you will need to stay hands on with generator or stiff AC power source until you get your particulars worked out.

If you plan to live off grid, you will need to reconsider everything, from the size and wattage of your TV to as simple as a coffee pot. LED lighting is a good start, but use less want less.

[a Cuppa Coffee]

I have a Syphon Coffee Maker. It is only on for about 90 seconds, coffee is in a thermal carafe. I also have a French press, and our range is LPG. I also have a wood stove with a cook plate on it. I could use the French press there. Even down to the TV and the flat screen computer monitor, they are the most efficient I could buy. Yes, I plan to downsize the battery bank to 900amp hours...and my 80amp CC is arriving tomorrow. I have been building a greenhouse/sunroom on my cabin and framing up to screen in the front porch all week...when not trying to sort out the solar problem of the week. Our house is on family land, and my parents are my next door neighbors. We have been using the power (AC) from my father's workshop to run all the construction tools.

[a Cuppa Coffee]

I have been using a Kill-a-watt on all major devices in my temporary residence whilst completing the build on our new home. My TV says it uses 45watts, but the Kill-a-watt has been logging it at just under 40watts. Use less, want less is right. We paired down when we sold our last home. I donated an entire moving truck to the Salvation Army of perfectly decent things we just didn't need. We plan to sort through our much fewer things again in a couple of weeks before we move into the cabin/tiny house.

[DanKegel]

Yeah, a few folks here - who may have good technical skills - think politeness is for other people. You just have to grin and bear it.

[a Cuppa Coffee]

Okay. 80 amp controller installed. I am leaving my 960watts at 12v and am dropping my bank size to 900amp hours. This leaves me with another 900 amp hours worth of batteries. I am disinterested in rewiring to a 24v or 48v system at this time...mainly because I have a really nice 12v inverter that I do not want to return or exchange.

I would like to have the second 900 amp hour bank fully charged and cycle in between them. I am sure there must be a DC switch that I could install to cycle between the two banks every few days. Anyone have any advice on how to switch between the two banks manually?

[Logan005]

"I am disinterested in rewiring to a 24v or 48v system at this time...mainly because I have a really nice 12v inverter that I do not want to return or exchange"

12 volts is not for off grid living. 12 volt inverters are dangerous toys. Batteries wired in Parallel will let you down sooner than later. Any money you save keeping it a 12 volt system will cost you big time in the near future. If you have not learned this by now, you are wasting our time.

[SunEagle]

Okay. 80 amp controller installed. I am leaving my 960watts at 12v and am dropping my bank size to 900amp hours. This leaves me with another 900 amp hours worth of batteries. I am disinterested in rewiring to a 24v or 48v system at this time...mainly because I have a really nice 12v inverter that I do not want to return or exchange.

I would like to have the second 900 amp hour bank fully charged and cycle in between them. I am sure there must be a DC switch that I could install to cycle between the two banks every few days. Anyone have any advice on hour to switch between the two banks manually?

Before you look into getting a manual transfer switch you really need to find out how many of those batteries are still in good shape. Then whatever you find you might be able to build the one bank at 900Ah.

[a Cuppa Coffee]

I monitored my batteries throughout the day today, no red flags flew. They are charging fine. I had my Fluke meter checking voltages whilst taking breaks from construction on the house. I am going to reorganize my battery box tomorrow... I will again give them all a thorough review. The manufacturer of my batteries says they are designed to be fully discharged and used in extreme conditions. Besides solar, they are often used in Golfcarts and Forklifts. Mine never were fully discharged, they were at 47% charge when my first controller played out, but they had only been lightly used for 3 days prior. I think I may have dodged a bullet. Like I said, I am going to monitor them closely tomorrow and continue testing them throughout the day.