My Solar Journey

DrJohnZoidberg said:
Yup that happens when somebody sees the same capacity as much more expensive options but don't realise you can never discharge lead acid batteries that low without damaging them. OP has definitely done the right thing here, not to say I would ever want to faff with all that effort of babying lead acids ever again.
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Yeah las require way to much care, thankful I've not had them for over 3 years now.
 
DrJohnZoidberg said:
Yup that happens when somebody sees the same capacity as much more expensive options but don't realise you can never discharge lead acid batteries that low without damaging them. OP has definitely done the right thing here, not to say I would ever want to faff with all that effort of babying lead acids ever again.
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and they take very long to charge/absorb also, too long if loadshitting more than once a day.
 
Lupus said:
Doesn't work
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Children of the Sun....

Children of the sun, see your time has just begun
Searching for your ways through adventures every day
Every day and night with the condor or in flight
With all your friends in tow, we search for the cities of gold

It's almost like an actual freaking adventure and journey - and the sun is the object. And gold at the end of it.
 
wingnut771 said:
Pics!Pics!Pics!Pics!Pics!Pics!Pics!Pics!Pics!Pics! Pics! Pics!Pics! Pics! Pics!Pics! Pics! Pics!Pics! Pics! Pics!Pics! Pics! Pics!Pics! Pics! Pics!
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Here’s some pics for you. The red packet on the left is fire mats that I will place under and in between the batteries. Will get a fireball also. Overkill but I want to be safe rather than sorry. IMG_9061.jpegIMG_9062.jpeg
 
wingnut771 said:
and they take very long to charge/absorb also, too long if loadshitting more than once a day.
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About 3 hours from early morning till 10:30 (Bulk plus absorption) with my current setup with the sun. They float for 4 to 6 hours thereafter which is sufficient for GEL.
 
denmendez65 said:
Here’s some pics for you. The red packet on the left is fire mats that I will place under and in between the batteries. Will get a fireball also. Overkill but I want to be safe rather than sorry. View attachment 1830747View attachment 1830748
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For interest I’m using a 35mm2 cable from the battery busbars to the inverter. 16mm2 from each battery string to the busbars. Equal length cables for all 5 strings. Same with the midpoint connections. Battery balancers on all to take care of any drift between the batteries.
 
denmendez65 said:
About 3 hours from early morning till 10:30 (Bulk plus absorption) with my current setup with the sun. They float for 4 to 6 hours thereafter which is sufficient for GEL.
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Bulk phase is quick using CC setting, CV absorption phase takes long as current trails off slowly.

LOL - those battery cases with the handles are identical to my lfp 12v 100Ah.
 
wingnut771 said:
Bulk phase is quick using CC setting, CV absorption phase takes long as current trails off slowly.

LOL - those battery cases with the handles are identical to my lfp 12v 100Ah.
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It’s an a CV setting. The Battery data sheet recommended it. Set a bit higher also because I cycle daily. So Bulk and Absorption is at 29V and float 27.6. Helps with charging the batteries quicker. The datasheet says 28.4V and 27V if standby use.

Those handles are a blessing. They saved me a lot of work when I had to dismantle everything to add the fuses, and again for the balancers lol. These damn things are heavy. Another pro for Lipo.
 
An add-on for my current future plans. In light of the current major increases to electricity I have come up with a plan for my main energy user which is the geyser. I already have a 2kw element installed and I have tested my current system to see If I can comfortably power it for at least 2 hours a day and I saw it can. I will get a 16l/min or 12l/min gas geyser fitted with its water supply coming from the geyser I have. From this calculator:

https://gas-installers.co.za/blog/how-much-gas-does-a-water-heater-use-per-month/

Based on the average tap water temperature being 16 degrees celcius, if I heat my geyser from inverter for just 1 hour a day to get it up to 25 degrees celcius. The gas geyser will cost me about 456 rand a month. Running the geyser for 1.5 hours (Current system can comfortably do it) I can reduce the consumption to 300 rand a month. This is assuming I use a 16l/min heater. The figures are even lower for a 12l/min heater. No need for a Dewhot valve.

After doing this conversion, I pretty much wont be touching eskom at all on most day. For the 10% of the days that are overcast etc, I will just run the geyser straight from the gas geyser with no preheating. After I test out everthing over the next 6 to 12 months. I suspect I will get a silent generator and get myself disconnected from Citipower. The Genie should cover me for the 10% of the days when I dont have enough solar generation.

The inverter already comes with contacts that can be used to start an electric generator which I suspect will happen about 20 to 30 days of the year? An ambitious plan with my current system but I suspect I can do all of this by end of next year latest. I am even considering adding an additional charge controller with its own 3 panels to the existing battery bank. It will be a 6k exercise but so far I have gone by fine with the current panels I have.
 
denmendez65 said:
An add-on for my current future plans. In light of the current major increases to electricity I have come up with a plan for my main energy user which is the geyser. I already have a 2kw element installed and I have tested my current system to see If I can comfortably power it for at least 2 hours a day and I saw it can. I will get a 16l/min or 12l/min gas geyser fitted with its water supply coming from the geyser I have. From this calculator:

https://gas-installers.co.za/blog/how-much-gas-does-a-water-heater-use-per-month/

Based on the average tap water temperature being 16 degrees celcius, if I heat my geyser from inverter for just 1 hour a day to get it up to 25 degrees celcius. The gas geyser will cost me about 456 rand a month. Running the geyser for 1.5 hours (Current system can comfortably do it) I can reduce the consumption to 300 rand a month. This is assuming I use a 16l/min heater. The figures are even lower for a 12l/min heater. No need for a Dewhot valve.

After doing this conversion, I pretty much wont be touching eskom at all on most day. For the 10% of the days that are overcast etc, I will just run the geyser straight from the gas geyser with no preheating. After I test out everthing over the next 6 to 12 months. I suspect I will get a silent generator and get myself disconnected from Citipower. The Genie should cover me for the 10% of the days when I dont have enough solar generation.

The inverter already comes with contacts that can be used to start an electric generator which I suspect will happen about 20 to 30 days of the year? An ambitious plan with my current system but I suspect I can do all of this by end of next year latest. I am even considering adding an additional charge controller with its own 3 panels to the existing battery bank. It will be a 6k exercise but so far I have gone by fine with the current panels I have.
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First thing you need to work out, is how much of your geyser is actually using that electricity.
I've got a normal geyser now and with people bathing and showering like people do in a household of 4, I use an average of 8 units a day with cooking.
As gas isn't actually that much cheaper than electricity for warming water. So first things first, calculate how much you actually spend on the geyser.
Plus remember you're now adding a geyser to your mix which means there is a higher chance of the batteries being drained
 
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Lupus said:
First thing you need to work out, is how much of your geyser is actually using that electricity.
I've got a normal geyser now and with people bathing and showering like people do in a household of 4, I use an average of 8 units a day with cooking.
As gas isn't actually that much cheaper than electricity for warming water. So first things first, calculate how much you actually spend on the geyser.
Plus remember you're now adding a geyser to your mix which means there is a higher chance of the batteries being drained
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I based it on the calculation from the link I shared. Gas consumption seems to be based on the delta difference between the incoming and outlet water temp you want.

If we assume 3 people showering (we are 2) it estimates about 400 rand a month if the incoming water has been preheat for at least an hour by the inverter (Chose an hour to not tap into batteries too much and geyser is connected to second output of inverter with higher cut off setting).

I will get the geyser installed soon and test it over time. Online calculators only take you so far. I will try 1.5 hrs and 2 hrs of preheating to see how gas consumption is affected also.
 
denmendez65 said:
I based it on the calculation from the link I shared. Gas consumption seems to be based on the delta difference between the incoming and outlet water temp you want.

If we assume 3 people showering (we are 2) it estimates about 400 rand a month if the incoming water has been preheat for at least an hour by the inverter (Chose an hour to not tap into batteries too much and geyser is connected to second output of inverter with higher cut off setting).

I will get the geyser installed soon and test it over time. Online calculators only take you so far. I will try 1.5 hrs and 2 hrs of preheating to see how gas consumption is affected also.
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Yup that's why I said just confirm that is indeed cheaper than electricity. As I've got 4 people and my electricity bill is around 500 with cooking from the stove and geyser, the only things not on the inverter.
Remember a traditional geyser will only work when it is trying to keep the water warm so if you set the thermostat to 55 degrees it will try keep the water at that. But generally it only goes down a little when you run water from the geyser or have it off for too long.

I had my geyser off for 3 days back in 2023 when it took sometime to get my generator installed, the water was warm not hot but warm, I ran the generator to warm it up for about an hour or so and water was back to 55 degrees.
From then on for the next two weeks I ran the generator at night for an hour or so to let it warm up the geyser and top up the batteries a little. Standing loss over a day was minimal, over 3 days it wasn't good but I also used it during those 3 days.
Gas is great for almost instant water, but having done the experiment myself it actually worked out more expensive than electricity. For cooking sure, but warming water not so much, though with 2 who only shower that might be fine.
 
Lupus said:
Yup that's why I said just confirm that is indeed cheaper than electricity. As I've got 4 people and my electricity bill is around 500 with cooking from the stove and geyser, the only things not on the inverter.
Remember a traditional geyser will only work when it is trying to keep the water warm so if you set the thermostat to 55 degrees it will try keep the water at that. But generally it only goes down a little when you run water from the geyser or have it off for too long.

I had my geyser off for 3 days back in 2023 when it took sometime to get my generator installed, the water was warm not hot but warm, I ran the generator to warm it up for about an hour or so and water was back to 55 degrees.
From then on for the next two weeks I ran the generator at night for an hour or so to let it warm up the geyser and top up the batteries a little. Standing loss over a day was minimal, over 3 days it wasn't good but I also used it during those 3 days.
Gas is great for almost instant water, but having done the experiment myself it actually worked out more expensive than electricity. For cooking sure, but warming water not so much, though with 2 who only shower that might be fine.
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Noted and thanks for your input. I also observed similar behaviour. But even with a timer etc, I cant get the consumption to under 6whr a day, any less and the water is luke warm. Pre heating made sense to me as even if the second output was switched off automatically by the inverter when the solar wasnt enough we could still get hot water from the gas geyser. The water heating doesnt rely on the inverter solely. I will most definitely over panel my current system with 2 more panels (if i can still find the brand) or just connect a 60A MPPT charge controller with its own array to boost solar production. Solar is free so the more preheating i can do, the less gas I can use.

I am surprised your bill is only 500 with 4 people using the geyser and a stove. Is that with the fixed charges? Ours is about the same but only 2 people using the geyser and with a gas stove. My wife uses the oven once a year at this point so I will convert it to gas as designing the solar for her once in a blue moon usage won't make sense.
 
denmendez65 said:
Noted and thanks for your input. I also observed similar behaviour. But even with a timer etc, I cant get the consumption to under 6whr a day, any less and the water is luke warm. Pre heating made sense to me as even if the second output was switched off automatically by the inverter when the solar wasnt enough we could still get hot water from the gas geyser. The water heating doesnt rely on the inverter solely. I will most definitely over panel my current system with 2 more panels (if i can still find the brand) or just connect a 60A MPPT charge controller with its own array to boost solar production. Solar is free so the more preheating i can do, the less gas I can use.

I am surprised your bill is only 500 with 4 people using the geyser and a stove. Is that with the fixed charges? Ours is about the same but only 2 people using the geyser and with a gas stove. My wife uses the oven once a year at this point so I will convert it to gas as designing the solar for her once in a blue moon usage won't make sense.
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Fixed charges add another 250 so it would be 750 total, remember I'm on solar and the only thing not on solar is oven and geyser.
Though they are the biggest users of electricity, they are only used for short periods so it doesn't add up. Sure an oven can use 5kw but you don't use it for a full hour most of the time, if you do you're dropping the temp down and than the power drops down.
Geyser is the same it's only on when it's warming the water, so generally after a bath or a shower, or washing dishes, but even than it's only for a short period of time.
When turning off a geyser you're allowing the water too cool down, so when you do turn it back on now it's got to work harder using more power.
 
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