Been doing a bit of reading on solar panels, power storage and so forth. It appears my suggestion of looking toward cat batteries and such would be only marginally effective and possibly, in the long run, more expensive. The issue appears to be in battery types. For example, home electrical systems tend to drag batteries down more than would be experienced in a motorized unit, since one just needs a burst of power to start, and the other draws on the power relentlessly. As such, deep cycle batteries are the common solution to home units. They are designed to deal with the constant deep discharge, whereas those we find in vehicles tend to only be required to produce power long enough to start the vehicle, after which the alternator takes over.

The old rule of NEVER letting any battery set discharged, even partially, for any period applies to deep cycle type batteries also. Perhaps more so with these systems, since that results in sulfation and dramatically shortens battery life. An expensive proposition, when you have to replace several batteries that cost in the area of three hundred or more each.

Places like Back Wood Solar (http://www.backwoodssolar.com) have a lot of good information on batteries. The information on such sites is helpful in all things battery related.

Here on the farm, we tend to have a lot of vehicles and equipment with batteries. Every spring, it was a dash to replace at least a couple batteries and over the course of the year, the farm spent at least five hundred tending such matters. About ten years ago, I set up a solar panel and ran wires to a few of the vehicles. Each vehicle got a single diode, stolen from an old piece of electronics, to stop the flow of electricity back from the battery back to the panel, or to another battery having a lesser charge state. Doing this helped avoid, or reduce spring [and even winter] surprises.

OTHER RANDOM BATTERY DETAILS:

The lower the charge on a battery, the more likely it is to freeze and be destroyed.

A maintenance charge should be considered, if a battery is going to set for an extended period.

Care and maintenance of a battery aside, initial battery quality goes a long way to determining the life of a battery.

Old batteries are good for cash - there is a demand for the lead and acid.

That is one gigantic find !! Hope you can get some use out of them. At the very least, they will be worth a core charge at the supply house.

millwright wrote:I have a 2 car shop behind the house. The roof on the shop would be a great place to install solar panels. The shop has a 100 AMP sub panel that is fed through the appropriate gauge wire which is fed through a conduit underneath my driveway.

I have two specific questions.

#1 Can I run the power (through an inverter) from the solar panels through the SUB panel back to the main panel? If I can then it would eliminate the need to SAW core through the concrete driveway back to the house. The shop is about 30 feet from the back of the house.

#2 What kind of roof structure is required to mount solar panels? The roof on the shop is a simple open truss with Asphalt shingles.

Thanks

When you install an alternative power source to your home, you should also install a Transfer Switch. This switch will completely isolate your alternate power source from the grid power source should you need to use your alternate source instead of the grid.

In cleaning the shop, I found twelve L16 batteries setting on a pallet. However, the owner of the property was caught in the web of domestic law (custody battles) and didn't finish his installation project. As such, the batteries, never used, set for ten years. I didn't have much hope for them and tried to explain the matter of sulfation to him. Regardless, I wired the [six volt] batteries into two banks, six each in parallel, then tied the two banks together in series to produce twelve volts, after which I applied two amps. The starting voltage was 5.4. A little over a week later, I now read 12.84vdc. So far, so good.

Meanwhile, back at the same ranch, I'm attempting to regain knowledge of electricity, which was left behind around forty years ago. I remembered learning the only [remote] hope for saving batteries that sat and, subsequently, sulfated, was to apply a charge, do a quick discharge, then repeat the process until some success was achieved, or the process abandoned. HOWEVER, an internet search offers new and better hope for batteriests (what the heck was that?) everywhere: Pulsating desulfinators. They inject a high voltage (e.g., 36 volts) for a split second. The signal is an AM one, like those used in AM radios. For reference, AM stands for amplitude modulation and is the adjustment of the amplitude of the strength of the signal, which can be seen on a oscilloscope as an increase of the sinewave). The signal is injected for only a split second and at a frequency which resonates within the sulfation crystals, breaking them up and putting them back into suspension for the battery's use. Batteries that, before application of the desulfinators, refused a charge came back with, for example, eighty-five amp hour storage capacity.

The desulfinators will not address shorting matters, such as when material has settled to the bottom of the battery and shorted plates. Nor will it address oxidation caused by exposure of the plates caused by too low of a fluid level. Still, for those of us interested in such matters, they appear a very worthwhile consideration, whether for use on a home power supply system or for use on our cars, tractors and so forth. Several reports indicate up to three times the life on batteries. At three hundred dollars or so a pop for certain batteries, this has definite appeal.

What I have decided to do is to stash away $35.00 a month for solar power repair and updates. If these batteries last 8 and a half years then I will have saved enough money to spring for a new set in that time period. I could have gotten a better price from a solar power company but after factoring the fuel and logistics of driving down there and back it was cheaper to get them locally at NAPA. One of my main problems is due to my remote location and getting things to where I live. The last batch of batteries lasted 20 years and I don't know why this recent battery bank failed so early. Another factor is that all of the batteries in your battery bank are suppose to be replaced at the same time. One low battery will cause the rest to work harder and they will quit on you earlier. I found out the hard way and tried replacing one at a time but that approach ended up costing me more money in the long run. There is no such thing as free power. On a solar power system there are components that fail, mainly the batteries and you have to reach into your pockets and pull out that cash .

Toepopper,
Might be good to plan on buying 2 each year or every other year and just add them into the array, it will give you the extra storage (assuming you have the floor space) and at the end of the life cycle of the 8 you just bought, you wouldnt be in the dark...??? The other thing that came to mind is if you can find an installer that buys them in volume, they may get a better price break. 8 batteries to one of those guys is a drop in the bucket. So systems have 40 or 50... etc.

Glad you back in the light, the darkness is scary!

I had to go ahead and buy 8 new L-16 batteries. They were on sale at NAPA auto parts store . Still cost me a bundle but at least we have power again and now I don't have to run the generator.

Going solar as you know ain't cheap so I think you may have to bite the bullet and get some Batteries. I don't recommend buying used batteries because you don't know what your getting. And there could be the potential to harm your other equipment.

Millright, I do not think what you have suggested is possible. Like dejure said, the 2 systems must be independent or something somewhere is sure to fry. Solar panels don't weigh very much and a standard (built to code) roof rafter or truss system will carry the weight without straining. Depending on which state you live in, you could mount some solar panels on the roof and run the wires into a device called a grid-tie unit which allows you to sell power back to the utility company during the day while the sun shines. This gets wired into the electric meter and the meter runs backwards while the sunlight hits the panels, reducing or eliminating your power bill. Most states will give you a tax deduction for investing in a grid tie system. Some areas of this country will not allow you to install solar panels because of asthetics. Another option would be to mount the solar panels on your garage roof and keep the garage system independent from your house. At todays prices, this might be impractical due to the large initial outlay of cashola as the prices on this equipment is now out of reach of working stiffs. A basic stand alone 48 volt system without the grid-tie will run you right around $20,000.

Where there is no solution, there can be no problem. I, certainly, do not have the familiarity our associates on this list have, but it's all doable. However, a few things come immediately to mind: 1) The amount of energy you are going to be able to push back into a system is limited by the cable feeding the system, but 100 amps is nothing to sneeze at. 2) If you're feeding into the system, you have to deal with feedback capable of injuring a lineman when all other power is out. 3) At low power usage times, you may want to feed the system, or sell back power, which many, if not all utilities are required to accept.

I've played with a lot of diodes to make my own rectifiers (in combo with a transformer) and unique switching systems and such. The way they work for those projects is they only allow current to travel in one direction. As such, if you had a monster diode (or the equivalent, such as a relay with normally open switching operated off main line voltage), you could isolate your system.

I have a 2 car shop behind the house. The roof on the shop would be a great place to install solar panels. The shop has a 100 AMP sub panel that is fed through the appropriate gauge wire which is fed through a conduit underneath my driveway.

I have two specific questions.

#1 Can I run the power (through an inverter) from the solar panels through the SUB panel back to the main panel? If I can then it would eliminate the need to SAW core through the concrete driveway back to the house. The shop is about 30 feet from the back of the house.

#2 What kind of roof structure is required to mount solar panels? The roof on the shop is a simple open truss with Asphalt shingles.

Thanks

I haven't had much luck with truck salvage yards. In the past I have hooked up used golf cart batteries, submarine batteries, and deep cycle trolling motor batteries to power the house. Cat and big rig batteries are 24 volt and are not meant for deep cycle use. They are designed for cold cranking a diesel engine with a 20 to 1 compression ratio and are drained in a short period of time. My house system runs on 12 volts. The best battery for the buck, even at these prices, is still the 6 volt L-16 deep cycle unit designed for powering remote houses and charged by solar panels. These batteries are wired in series as well as in paralell to give 12 volts DC and each battery is rated at 350 amp hour capacity. They weigh about as much as a sack of Portland cement. Yesterday, I bought 8 new L-16's at the NAPA parts store in town. After shopping around for a week, they gave me the best price at $220 per unit, plus a $25 core charge rebate for the old batteries. I am still suffering from sticker shock and it just torques my jaws how the price of every basic necessity has skyrocketed so some corporate executive puke can get his 30 million dollar bonus at the end of the year.
It took 6 hours to disconnect, remove, and get the old batteries into the back of my pick up truck. I had to wrestle/ slide them downhill on a scaffold plank into the truck. The new batteries were removed by parking the truck above the house site and sliding them down to the ground, then carted one at a time on a 2 wheel dolly and set in place. This operation took 7 hours before the electricity was flowing once again. Its great to be independent but sometimes it can be a real pain in the !@#%^* .

That's terrible! The price is bad enough when you could get them at the low price - sounds like they are holding a gun to your head now.

I don't have much experience with battery shopping, but dejure has the right idea - if you can explore salvage sources.

Here's a link to battery ratings by type BATTERY COMPARISONS for Remote Power Systems

Best of luck to you in your search - please get back to us if you find anything like a good source or a good price.

Regards,
Pat

I don't know squat about your battery array (e.g. the final voltage), but DC is DC and assembling a group of batteries in series and parallel to achieve a voltage isn't a big deal. As such, is there a chance one could score some cat (e.g., D-8) batteries or something from truck wrecking yards? My buddy bought all his used from the phone company. They were constructed of see through material so you could tell at a glance interior structure and water acid level.

The 8 batteries that I use to power my house have lost their ability to hold a charge. They are finito and they have decided to crap out on me at this time of the year when they are needed the most. These L-16 type batteries have lasted eight and a half years. They cost $85. apiece when I bought them but are currently selling for $220 each. Thats a whopping $1760. plus tax !! We are rolling up all the cans of coins and figuring ways to rob Peter to pay Paul to get new batteries. One solar power equipment store tried to sell me these batteries at $420. apiece. They must be drunk or are smoking the whacky tobacky to come up with such an outrageous price. How can something as basic as a lead cell battery have jumped up in price by so much? This is insane. As a consequence, my time on the computer is now restricted to the hours of the day when the sun shines directly onto my solar panels and in the evening when we run the generator to charge batteries and run the lights.