Common battery voltage for off grid solar batteries

[thekay]

Hello everyone,

I would like to have other findings on the above subject. As for me, I have researched and found out that the most common battery for off grid solar power is the 12 volt batteries. However, one could argue that it depends on the application used, the more applications used, the higher voltage.

Any contributions? What do you consider as the most commonly used voltage battery? (6, 12, 48 etc.)

Kind Regards

Kelvin (thekay)

[Sunking]

12 volt is for toys and RV's. Any serious Solar system for home application will be 48 volts or higher.

[thastinger]

Mine is not a large system at all but it is still a 48V system via 6V batteries in series.

[thekay]

Thanks guys. Have you seen this video Ben Law. He talks about living off grid and how he uses a combination of solar and wind to power up his home. He uses 12V, but then again he states that he doesn't use much applications at home. What do you think?

[russ]

Thanks guys. Have you seen this video Ben Law. He talks about living off grid and how he uses a combination of solar and wind to power up his home. He uses 12V, but then again he states that he doesn't use much applications at home. What do you think?

The windmill is useless most places and probably for him as well. Too low and too small. They do have good wind in many locations in the UK but you have to be up above the tree tops to get much.

With 12V the cable size becomes too large - meaning too expensive for most

[Mike90250]

It all depends on what you do Off-Grid. If it's a weekend cabin, a battery & some LED lights are fine. A hermit in the bush might scale up to 24V to keep the entertainment system working.
A family living off grid will need a even larger system - 48V
After 48V, it becomes much tougher to find gear, because a different electric code kicks in at 50V.

The reason for increased voltage, is to decrease amps in the wires, much like large appliances use 240V because they only need half the amps that 120V requires.

[SunEagle]

It all depends on what you do Off-Grid. If it's a weekend cabin, a battery & some LED lights are fine. A hermit in the bush might scale up to 24V to keep the entertainment system working.
A family living off grid will need a even larger system - 48V
After 48V, it becomes much tougher to find gear, because a different electric code kicks in at 50V.

The reason for increased voltage, is to decrease amps in the wires, much like large appliances use 240V because they only need half the amps that 120V requires.

Or just go the way Edison wanted and stay on DC. Less losses since there wouldn't be any inverter required. Just have to watch your voltage drops.

There has been some direction in manufacturing to convert their HVAC equipment over to DC and run them off of renewable energy sources. I just don't think DC will catch on in the home owner sector due to lack of appliances and entertainment systems for that voltage.

[PNjunction]

I had to see that video twice before it hit me - it appears that he is only using an inverter in the shed to power his tools, but running DC all the way from the shed to the house. That looks like a long distance for DC, so I can only imagine the huge voltage drop he's getting!

I sure hope he's running some HUGE cabling from the shed to the house in that case - although if all it is doing is powering a cd player or two, maybe not so important.

I got a nice vibe from that video - and seems like a nice guy. Made me want to do something similar although I'd be blasting some retro Supertramp tunes in the background of the shed.

[Sunking]

Or just go the way Edison wanted and stay on DC. Less losses since there wouldn't be any inverter required.

Not necessarily. Take NYC for example. Manhattan Island was DC up until the mid 90's. It is all gone because it was so outdated and inefficient. The reason is becaus eit had to operate at fairly low voltage of 600 volts, and the converters to drop the voltage down were very inefficient as they are not DC to DC converters.

For a house what DC voltage would you use? Well most DC applicances ar 12 volt made for the RV and boat markets right? Those are cheaply made and inefficient. If you have anything that requires significant power of say over 100 watts means you have to use very large expensive wire and even then the losses are significant. In a 12 volt DC system you are going to loose 15 to 30% maybe even more in wire losses alone. You might say well use 24 or 48 volt right? Now try to find stuff other than a fridge that can operate at 24 or 48 volts and how much they cost.

Not trying to beat up on you, the idea is noble, but once you consider the extra expense and losses it just does not add up.

[SunEagle]

Not necessarily. Take NYC for example. Manhattan Island was DC up until the mid 90's. It is all gone because it was so outdated and inefficient. The reason is becaus eit had to operate at fairly low voltage of 600 volts, and the converters to drop the voltage down were very inefficient as they are not DC to DC converters.

For a house what DC voltage would you use? Well most DC applicances ar 12 volt made for the RV and boat markets right? Those are cheaply made and inefficient. If you have anything that requires significant power of say over 100 watts means you have to use very large expensive wire and even then the losses are significant. In a 12 volt DC system you are going to loose 15 to 30% maybe even more in wire losses alone. You might say well use 24 or 48 volt right? Now try to find stuff other than a fridge that can operate at 24 or 48 volts and how much they cost.

Not trying to beat up on you, the idea is noble, but once you consider the extra expense and losses it just does not add up.

I understand about the voltage drop using low voltage but figured the distances for the wire runs in a house would not be a big deal.

I had read about Edison using DC as a distribution voltage in Manhattan so I figured there were appliances that could run off it. What did they power back then besides lighting?

[Sunking]

I had read about Edison using DC as a distribution voltage in Manhattan so I figured there were appliances that could run off it. What did they power back then besides lighting?

Everything in Manhattan. Elevators, trains, air conditioning, heating, lighting. You name it. Many of the buildings like apartment used inverters for the residence.

For example building like the Empire State Building, Chrysler building, and even the World Trade Towers had to install Rectifiers to run all the stuff. Otherwise they would would have had to change out everything for AC equipment. NYC Manhattan is one F'ed up place electrically.

Westinghouse and Morgan won the Electrical war with Edison. JP Morgan hated Edison, and Westinghouse via Telsa had the better idea. It took Morgan to see it and make it happen who knew nothing about electricity. Hell JP Morgan even saved the US government and our country. Not many know that.

[SunEagle]

Everything in Manhattan. Elevators, trains, air conditioning, heating, lighting. You name it. Many of the buildings like apartment used inverters for the residence.

For example building like the Empire State Building, Chrysler building, and even the World Trade Towers had to install Rectifiers to run all the stuff. Otherwise they would would have had to change out everything for AC equipment. NYC Manhattan is one F'ed up place electrically.

Westinghouse and Morgan won the Electrical war with Edison. JP Morgan hated Edison, and Westinghouse via Telsa had the better idea. It took Morgan to see it and make it happen who knew nothing about electricity. Hell JP Morgan even saved the US government and our country. Not many know that.

I didn't know that about Manhattan. You would think they still had DC appliance available. Too bad.

I do know that JP funded Tesla to build his electrical "transmission tower" until he found out Tesla wanted to give the power away. JP dropped him like a hot potato.

[Sunking]

I didn't know that about Manhattan.

Well if you want to know more the last DC plant was taken of-line in Nov 2007 More info here. Manhattan had one of the first Electric systems in the USA. Tesla worked for Edison and Morgan financed both Edison and Westinghouse. Tesla was a brillant engineer but dumb as a rock in business and died penniless. JP Morgan ended up with all Telsa's Patents. Tesla after he fell out with Edison went to work for Westinghouse and Westinghouse owned all of Teslas's Patents.

I do know that JP funded Tesla to build his electrical "transmission tower" until he found out Tesla wanted to give the power away. JP dropped him like a hot potato.

My reference was not in reference to the Tower, Morgan pulled funds for that. Morgan saved the USA not once but twice. First time was in later 1890's under Grover Cleveland administration. In th e1890's the US currency was gold standard, and the economy tanked. US Bond Holders made a run on trading their US bonds for Gold which the USA had to pay. Th eUS Treasury went all the way down to $9 million dollars, and there was one known holder with a $10 million dollar bond, and a total of some $40 million around other investors. The USA was in Default, an dGrover Cleveland had to go to JP Morgan to secure a loan in gold. JP gave th eUS Treasury 100 Million in gold. That stopped the run on bonds, stabilized the economy, saved the USA government, and made JP Morgan unknown millions in repayment which gained him great criticism.

The in 1905 Wall Street and US banks went bankrupt, when Westinghouse was insolvent. The economy crashed. JP Morgan who owned the railroads, oil companies, and power companies bailed out Wall Street and bought Westinghouse. That is how Morgan gained control of all Tesla and Westinghouse Patents and Assets. He also bought Edison Electric and changed the name to what we call GE today.

Morgan is also considered by many the father of the modern automobile. Oil companies had this nasty by product no one knew what to do with. When they distilled oil it produced about 50% of this nasty vile byproduct that everyone thought was to volatile and dangerous to work with. It was dumped into rivers and streams which caused lake and river to catch on fire. Morgan figured out what to do with it. He hired engineers to make a internal combustion engine to burn this vile nasty stuff they called GASOLINE. You know the rest of the story.

[SunEagle]

Well if you want to know more the last DC plant was taken of-line in Nov 2007 More info here. Manhattan had one of the first Electric systems in the USA. Tesla worked for Edison and Morgan financed both Edison and Westinghouse. Tesla was a brillant engineer but dumb as a rock in business and died penniless. JP Morgan ended up with all Telsa's Patents. Tesla after he fell out with Edison went to work for Westinghouse and Westinghouse owned all of Teslas's Patents.

My reference was not in reference to the Tower, Morgan pulled funds for that. Morgan saved the USA not once but twice. First time was in later 1890's under Grover Cleveland administration. In th e1890's the US currency was gold standard, and the economy tanked. US Bond Holders made a run on trading their US bonds for Gold which the USA had to pay. Th eUS Treasury went all the way down to $9 million dollars, and there was one known holder with a $10 million dollar bond, and a total of some $40 million around other investors. The USA was in Default, an dGrover Cleveland had to go to JP Morgan to secure a loan in gold. JP gave th eUS Treasury 100 Million in gold. That stopped the run on bonds, stabilized the economy, saved the USA government, and made JP Morgan unknown millions in repayment which gained him great criticism.

The in 1905 Wall Street and US banks went bankrupt, when Westinghouse was insolvent. The economy crashed. JP Morgan who owned the railroads, oil companies, and power companies bailed out Wall Street and bought Westinghouse. That is how Morgan gained control of all Tesla and Westinghouse Patents and Assets. He also bought Edison Electric and changed the name to what we call GE today.

Morgan is also considered by many the father of the modern automobile. Oil companies had this nasty by product no one knew what to do with. When they distilled oil it produced about 50% of this nasty vile byproduct that everyone thought was to volatile and dangerous to work with. It was dumped into rivers and streams which caused lake and river to catch on fire. Morgan figured out what to do with it. He hired engineers to make a internal combustion engine to burn this vile nasty stuff they called GASOLINE. You know the rest of the story.

I was familiar with the Edison, Tesla, Morgan, Westinghouse connection but not the more in depth information concerning Morgan and the US.

Thanks for the nice history lesson.

[Sunking]

Thanks for the nice history lesson.

Well I cheated in college sort of. For US History/Politics/Business and English I used the same term paper for all four classes. I covered Morgan, Tesla, Edison, Edison, and Grover Cleveland from the period of 1890 to 1910. It blended nicely.