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Sean live chat say he only run off-grid for one hour at night with battery . I have over 40 kwh lithium ion battery and still need to recharge at night . Battery cost more than any inverter or solar panel and the copper wires needed makes complete off-grid too expensive for me .
I'm guessing you have a fair amount resistive heating, both room and water, and several people in the residence?
I can not run a heat pump on battery but run a large 1 hp 240vac swamp cooler on continously in the summer and refrigerator and freezer . I have to rechage one third of the battery at the same time I am using the other two third of the baatery to run the inverter off-grid at night . The problem is I only have 6000 kw of solar panel to charge two third of the battery during the day . The battery is only usable from 62 volt to 46 volt . I will need another 20000kwh of battery or 60000 kw of solar panel which is impossible to hide in the backyard with 7 palm trees blocking the sun . One man a few miles from me hide 60000 kw of solar panel in his backyard and use a 12kw inverter with built-in MPPT solar controller to run his heat pump 12 hours a day using only solar panel and 4 AGM battery .
I have 1/10 of the battery storage that you have. It is 2.4 kwh of LiFePO4 batteries and about 2.4 kwh of flooded batteries which cannot discharge as deeply. There is a new experimental battery technology in development that uses a molecule of carbon, hydrogen and nitrogen that can change shape and become energy-rich when exposed to sunlight. It can be stored, as a liquid, for years, and can release stored energy on demand, in the form of heat.
https://lithium-news.com/a-breakthrough-in-solar-energy-storage/
I run off grid 24/7 with 10KWH. No AC needed here and heat is powered by diesel.
Most consumption is idle draw from misc devices and freezers.
The only difficult component to deal with is the electric drier.
Thankfully the GS is very reliable. 3000 hours already and nothing to complain about.
FYI, you can buy ~2.5KWH of LiFePO4 for ~350$. (everything already done for you - just hook up) It's not really that expensive when appropriately sized...
20000kwh of battery or 60000 kw of solar panel
Suppose to be 20000 watt hour of battery or 60000 watt of solar panel . Thank you .
FYI, you can buy ~2.5KWH of LiFePO4 for ~350$. (everything already done for you - just hook up) It's not really that expensive when appropriately sized.
My 5 MSB 60A solar charge controller is set at 66volt so LiFePO4 will not match . Used lithium ion BMW car battery is 300 dollars each include shipping tor 2.0KWH which is what I am using . If I get 10 more then I can be off-grid at night but the Delta fan sound like a jet engine in my back yard so maybe still not be completly off-grid because of the noise .
I have 1/10 of the battery storage that you have. It is 2.4 kwh of LiFePO4 batteries and about 2.4 kwh of flooded batteries
I started 3 years ago with 4 kwh AGM battery that is till being use every day . I use a special AGM charger to keep it like new . I also had LiFePO4 batteries but in the begining I let it discharge too low and is damage . At the time I know nothing about charging battery .
It can be done but it can't be done with an on-grid lifestyle. You have to change how you live in most aspects. So do laundry during the day. Run the air conditioner hard when the sun is shining and get the house chilled and coast through the night. Put a timer on the ghost loads so they turn off while you're asleep. The electric water heater shouldn't be allowed to cycle after dark either. Etc.
It can be done but it can't be done with an on-grid lifestyle. You have to change how you live in most aspects.
I can live off-grid on solar and battery . My wife get mad when the house is hot and do not care how much the heat pump cost in electric usage . It is over 100 degree every day now and next month it will be over 100 degree all night . I uae to grow over 100 pounds of squash in my backyard but now nothing grow but bermuda grass and russian giant sunflowers .
On 5/29/2022 at 6:47 AM, InPhase said:It can be done but it can't be done with an on-grid lifestyle.
Words to live by, ...literally!
We have a very large battery bank (lifepo4) and more than enough solar to keep it charged and run the house 24/7 from late March to late October (usually!) The exceptions are the electric dryer and the central AC, both of which run when needed only on grid power. My 15kw powerjack can't run either one reliably so they are only grid connected. (The powerjack is really just a decent 6kw, ya know) My wife hangs the laundry out in good weather (most all the time march to october) and the central AC unit is typically only needed a couple of weeks per summer. The oven is used in the daytime and she tries to limit its use to sunny days. The microwave is not enough to worry about. Two freezers and a large refrigerator, plus a well pump are the normal larger loads.
When we have consecutive rainy days (like right now!) I have to keep an eye on things but there is usually enough solar to get by on without switching to grid. If my wife really wants to use the oven on a cloudy day I can always switch it to grid for the time she's using it.
The water heater has its own battery bank (also lifepo4), solar to charge it, and an 8kw (realistically a 3kw) powerjack that only runs the water heater in powersave mode. The 8kw has a timer to limit it's running to daytime hours, a protection circuit to allow it to run only when the batteries are in proper voltage range, and it has been running winter and summer non-stop for nearly 2 years, providing hot water for my wife and I.
Between October and March if there's enough sun I run the house on the powerjack during the day and switch to grid overnight. Sadly I have to use grid power a lot in december (shortest days). I could run on batteries more than I do in winter but I'm trying to preserve my battery life by going easy on them. Someday soon there might be no grid to switch to, then we're all on our own, like it or not.
On 5/30/2022 at 8:34 PM, dochubert said:Words to live by, ...literally!
We have a very large battery bank (lifepo4) and more than enough solar to keep it charged and run the house 24/7 from late March to late October (usually!) The exceptions are the electric dryer and the central AC, both of which run when needed only on grid power. My 15kw powerjack can't run either one reliably so they are only grid connected. (The powerjack is really just a decent 6kw, ya know) My wife hangs the laundry out in good weather (most all the time march to october) and the central AC unit is typically only needed a couple of weeks per summer. The oven is used in the daytime and she tries to limit its use to sunny days. The microwave is not enough to worry about. Two freezers and a large refrigerator, plus a well pump are the normal larger loads.
When we have consecutive rainy days (like right now!) I have to keep an eye on things but there is usually enough solar to get by on without switching to grid. If my wife really wants to use the oven on a cloudy day I can always switch it to grid for the time she's using it.
The water heater has its own battery bank (also lifepo4), solar to charge it, and an 8kw (realistically a 3kw) powerjack that only runs the water heater in powersave mode. The 8kw has a timer to limit it's running to daytime hours, a protection circuit to allow it to run only when the batteries are in proper voltage range, and it has been running winter and summer non-stop for nearly 2 years, providing hot water for my wife and I.
Between October and March if there's enough sun I run the house on the powerjack during the day and switch to grid overnight. Sadly I have to use grid power a lot in december (shortest days). I could run on batteries more than I do in winter but I'm trying to preserve my battery life by going easy on them. Someday soon there might be no grid to switch to, then we're all on our own, like it or not.
How deeply do you discharge your LiFePO4 batteries? As low as 20%?
How deeply do you discharge your LiFePO4 batteries? As low as 20%?
According this youtube he say do not discharge to 2.5 volts but discharge to 3.1 volts . LiFePO4 batteries has a flat discharge curve and 2.5 volt will damage the battery .
Busting the 20%-80% SOC myth for LiFePO4 batteries.
Jun 2, 2022
I saw that clip from Andy. The only thing he busts there is the method less experienced (?) people try to do 80/20 cycling with, voltage monitoring. 80/20 cycling absolutely improves lifepo4 cycle count and he does attempt to disprove that either. There's plenty of research out there about it going back decades (yes, lifepo4 is quite old).
How deeply do you discharge your LiFePO4 batteries? As low as 20%?
With LiFePO4s, they actually tend to dislike being fully charged. For myself, i try to keep SOC between 75% to 25%.
So Depth Of Discharge is somewhat of a different concept compared to Lead Acids. It's not merely a "50%" or "100%" anymore, it's a SOC range; 100-40 will result in [significantly] shorter cycle life than 70-10, even though they both grant 60% capacity.
I saw that clip from Andy. The only thing he busts there is the method less experienced (?) people try to do 80/20 cycling with, voltage monitoring. 80/20 cycling absolutely improves lifepo4 cycle count and he does attempt to disprove that either. There's plenty of research out there about it going back decades (yes, lifepo4 is quite old).
Yeah... SOC shunt is an absolute must.
The science is pretty clear. LiFePO4's are mildly damaged when fully charged, a chemical reality much the same as how 0% will kill them.