Taking lights and internet off the Grid (mostly)

The_Ogre

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Not bad, but I would not go for a 12v system as its easy to burn down your schit!

If you have the means, get as high a voltage inverter as possible. 1200w at 12v means your cables need to be able to handle 100a (moers thick, lots of losses, you fart too loud and it causes a fire), while 1200w at 48v needs only 25a, which in turn means you can run thinner cables and run them a bit further. Remember, this is the reason why long distance power lines use step up transformers to jack the voltage to 10's of 1000's of kV's and run only a few amps through them.

The other reason is that its also much easier to expand in future with a high-voltage inverter.
 

ToxicBunny

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Yeah... I'm looking at at least a 24v inverter, and probably the 48V instead...

Nothing I'm planning on running will be drawing huge amperage so don't need a large amperage feed.
 

TheChamp

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Yeah... I'm looking at at least a 24v inverter, and probably the 48V instead...

Nothing I'm planning on running will be drawing huge amperage so don't need a large amperage feed.
You are just going to unnecessarily limit your run time with the 48V system, a 24V one should be good enough to lower the operating current.
 

ISP cash cow

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If you connect a wall inverter up with a couple of deep cycle batteries and just run a couple of lights, a couple of computers, TV and decoders how long do the batteries generally last (during load shedding at night) before needing recharging?

I am looking at going all in and getting some solar geysers and then get a grid tied system with solar and a backup generator? I just want to know what equipment I will need to start with and if there is any recommended companies out there that can do the installation for me.

I am not much of an electrician
 

ToxicBunny

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You are just going to unnecessarily limit your run time with the 48V system, a 24V one should be good enough to lower the operating current.

I'm still learning in all of this so yeah.... but in terms of limiting run time, initially that would be an issue, over the longer term as the system expands that may not be.

I have to balance solving a "problem" right now, as well as speccing something that is capable of growth into something else as well.
 

The_Ogre

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You are just going to unnecessarily limit your run time with the 48V system, a 24V one should be good enough to lower the operating current.
I'm not sure I understand what you're saying here?
 

Neville

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Novice question, if I have a 24V invertor/charger, do I need 24V batteries? Or do I simply connect 2 x 12V batteries in series?
And what's up with all the 6V batteries I see for sale? What are those used for...or how?
 

greg_SA

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Novice question, if I have a 24V inverter/charger, do I need 24V batteries? Or do I simply connect 2 x 12V batteries in series?
And what's up with all the 6V batteries I see for sale? What are those used for...or how?
Yes, 2 x 12V in series is what most people do for a 24V system.

I chose to go for 12V, since my system is small, and I wanted the option to run from 1 battery only. When I go camping, I often take one battery with me...
 

greg_SA

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I have to balance solving a "problem" right now, as well as speccing something that is capable of growth into something else as well.

I went through this previously too :)

It is very easy to get carried away with these UPS / inverter systems. When I started, I wanted to make load shedding less annoying. Mainly just keep the lights on. Then the design started getting scope creep, and eventually I was sitting at a huge budget which was more like an off-grid solar system.

I think it is important to decide up front if you want a load shedding UPS (without solar) or a proper off-grid solar system. The initial equipment the you buy needs to be the best for your intended purpose. Systems don't always expand easily.

In the end I went back to basics, as I only wanted a basic UPS for lights and other essentials (internet/TV or PC).
 

Pineapple Smurf

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6v and 2v batteries usually have massive amp capacities and are ideal for people to wire up many of these in series to achieve a high voltage rating.
Not for normal day to day stuff that we here on the forum are discussing at the moment.
Mostly for off the grid home and work solutions.
 

ToxicBunny

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I went through this previously too :)

It is very easy to get carried away with these UPS / inverter systems. When I started, I wanted to make load shedding less annoying. Mainly just keep the lights on. Then the design started getting scope creep, and eventually I was sitting at a huge budget which was more like an off-grid solar system.

I think it is important to decide up front if you want a load shedding UPS (without solar) or a proper off-grid solar system. The initial equipment the you buy needs to be the best for your intended purpose. Systems don't always expand easily.

In the end I went back to basics, as I only wanted a basic UPS for lights and other essentials (internet/TV or PC).

Yeah, I want to eventually go solar to some degree just to lessen my reliance on the grid for certain things.... not for everything.
 

Pineapple Smurf

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Yeah, I want to eventually go solar to some degree just to lessen my reliance on the grid for certain things.... not for everything.
Yeah the thing that puts me off going off the grid completely is the cost of batteries, and you have to replace them every 5 to 10 years, eina.
I want to go grid tied whereby you have no batteries but you generate say 3kw during the day, anything you consume beyond that it now taps into eskom and uses what it needs.
As soon as your demand goes below 3kw it is then purely free from what you are generating.
That way you run the expensive things during the day for "free" such as washing machines, swimming pool pumps, air con all day (heater in winter) etc etc.

Drawback to this is it will only work during the day, Duh.
And when there is load shedding the gridtied unit also shuts down (stupid, but it does).

But its a small price to pay knowing you can generate free electricity for decades.
 

ToxicBunny

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Yeah the thing that puts me off going off the grid completely is the cost of batteries, and you have to replace them every 5 to 10 years, eina.
I want to go grid tied whereby you have no batteries but you generate say 3kw during the day, anything you consume beyond that it now taps into eskom and uses what it needs.
As soon as your demand goes below 3kw it is then purely free from what you are generating.
That way you run the expensive things during the day for "free" such as washing machines, swimming pool pumps, air con all day (heater in winter) etc etc.

Drawback to this is it will only work during the day, Duh.
And when there is load shedding the gridtied unit also shuts down (stupid, but it does).

But its a small price to pay knowing you can generate free electricity for decades.

I'm sitting in a different boat..

The solar aspect is being looked at so that I can take the lights, my network and possibly the TVs and such off the grid entirely. Everything else can run off the grid when it is available.
 

Pineapple Smurf

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I'm sitting in a different boat..

The solar aspect is being looked at so that I can take the lights, my network and possibly the TVs and such off the grid entirely. Everything else can run off the grid when it is available.
Those are all small power consumption items and shouldn't affect your electricity bill every month.
lights 10w each
network 100w (im guessing)
tv 120w

All in all you will be consuming 500w to 800w from sunset to sleep time. I use 400 watts in my apartment

During the day
Washing Machine 300 watts
Tumble Dryer 2000 watts
Geyser 3000 watts
Heater 2000 watts
Air Con 1600 watts
Swimmin Pool Pump 1300 watts

it's the daytime that these units should be running. If you really concerned about your night time consumption before going to bed then another possibility is when you get your Solar Inverter make sure it has 2 x MPPT inputs so you can connect a wind turbine to it as well.

That way you generate electricity at night when the wind is pumping.
 

TheChamp

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I'm not sure I understand what you're saying here?
A 12V system with 4 * 100Ah batteries connected in parallel gives you a total combined capacity of all the 4 batteries 400Ah, the problem with this will always be the high operating currents needed to give you the power you need, the solution now becomes a 24V system, with the same number of batteries your capacity is now halved to 200Ah but the operating current is lowered for the same output power, going to 48V will mean your capacity is lowered and the result is equal to the capacity of only one battery 100Ah, compare that to the 12V and the 24 volts and you will see how reduced is the battery capacity, battery capacity is directly propotional to the run time you will enjoy on your system.
 
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Pineapple Smurf

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A 12V system with 4 100Ah batteries connected in parallel gives you a total combined capacity of all the 4 batteries 400Ah, the problem with this will always be the high operating currents needed to give you the power you need, the solution now becomes a 24V system, with the same number of batteries your capacity is now halved to 200Ah but the operating current is lowered for the same output power, going to 48V will mean your capacity is lowered and the result is equal to the capacity of only one battery 100Ah, compare that to the 12V and the 24 volts and you will see how reduced is the battery capacity, battery capacity is directly propotional to the run time you will enjoy on your system.
Please wire multiple batteries in parallel the correct way.
Took me many years of frustration to figure it out.
http://www.smartgauge.co.uk/batt_con.html
I'm using method 3 here for my 10 batteries.
 

ToxicBunny

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Those are all small power consumption items and shouldn't affect your electricity bill every month.
lights 10w each
network 100w (im guessing)
tv 120w

All in all you will be consuming 500w to 800w from sunset to sleep time. I use 400 watts in my apartment

During the day
Washing Machine 300 watts
Tumble Dryer 2000 watts
Geyser 3000 watts
Heater 2000 watts
Air Con 1600 watts
Swimmin Pool Pump 1300 watts

it's the daytime that these units should be running. If you really concerned about your night time consumption before going to bed then another possibility is when you get your Solar Inverter make sure it has 2 x MPPT inputs so you can connect a wind turbine to it as well.

That way you generate electricity at night when the wind is pumping.

I'm still scoping everything.. but heavy draw items can live off the "off-grid" system... its too expensive to take things like a tumbledryer/microwave etc off grid for the moment.
 
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