Batteries connection

[PNjunction]

You may have a different citation with your electric cost and power quality but in my opinion you will still end up spending a lot more for a solar/battery system then just purchasing power from your utility.

That's what most people don't want to hear! It can't be!!

Once that fact is accepted, if they continue on, they try to do the cheapskate / lowball route, and end up paying even MORE when the junk fails and has to get replaced with quality gear.

Oh well, we try.

[ANIKHTOS]

hello

I just did the calculation with only the battery cost. There is also the cost of the pv panels, battery charger, DC to AC inverter along with cabling and fusing. So the up front cost will be much more than 3 times the cost of purchasing power from my utility. And a 200Ah battery may cost me only $300 today it will be more in 5 years. The costs keep adding up.

I am lucky because my power quality is pretty good. But the chance of it stopping is high during bad weather. Then I would use an emergency generator which will provide me much more power than a battery system for much less cost including the fuel to run it.

You may have a different citation with your electric cost and power quality but in my opinion you will still end up spending a lot more for a solar/battery system then just purchasing power from your utility.

well thats why you were learning maths in school
you find out the variables
you crunch the numbers
and then you make your decision
thats why i am here research research research finding out the variables

i do not want to be surprise you forgot that now you need tons more money to do that

form how you connect the batteries to every aspect research
even something simple like how is the best way to connect the batteries can be a cause to make it worth while or not

going off grid or not i will still make a small pack for an emergency case the electricity will be off from a storm or what ever

the battery aspect is so huge
different chemistries, different capacities available, different voltage, safety of batteries, discharge rate of batteries
cost of batteries

and of course how much money you have
i know the best is to buy all batteries at the same time
but if you can not afford them what will be the second best option to start a pack and increase it as time passes?

thats also an interesting topic
also to there are circuits you can use to connect multiple strings and draw an equal amount from each one or if 1 input is way higher they only draw from there
when the volts equalize they draw with the others

there are interest things out there that increase the cost the complexity of the installation but also increase the possibilities and management of the installation

but the more circuits you add the more power you loose to them
so it is always you gain something you loose something
they real question is what i real must have and what i can live without it

life is compromising
its like poker you play with the hand you are given not with the hand you wished to be given

[SunEagle]

welll different people
in different locations
have different outcomes
while you pay 0,12 dollars per kw i have to pay 0,3 euro per kilowatt so that 34 cents at your country currency
while a battery just a very fast check 12v 200ah costs 289 euros 322 usd

so in my country the 322 dollars to buy the battery can buy me 947kw so do you see a difference????

while you say or me its 3 times more expensive for my side
its 8% more expensive from battery side

and thats how situation is right now
if tomorrow all the extra taxes you get in electric bill come to an independent bill
then cost will go to 0.12 euro per killowat given current prices

so if electric bill is only electric then situation here will be like the situation in your country

and in spain they talk to but a new law that taxes sun and effectively makes you go even in 20 years of operation
and i am talking for having solar panels selling energy to the grid 20 years to get even with life expectancy of panels 25 lol
also in the same law all off grid houses will have to get on grid!?!?! and pay an electric company

i do not know the quality of power in your country put here the quality sucks
and what sucks even more even if your things are toasted from the bad quality you can not sue the company to get
your items replaced by them
maybe in your county you can have liable the company but not in here
it is insane
yes it is
but thats the situation as it is now
maybe later the poco will be liable and thus the will provide better quality than the one we have now

and of course what it end ups is what you can afford to pay

i talk with people going off grid in greece and they say no i want to use my ac and i say to them okey
when was the last time you used it
they say 3 years ago
i can not afford to use it lol
another said and if i want to use a melding machine that consumes 10k what i will do
i ask him how often you use one
and he said never

you know we can start having hypothetical conversations or more realistic ones
yes i want to use ac but it i can not afford to pay it even when connecting to a poco i can not use the ac as an argument to stay on grid
and since that people are on pension their financial is not going to improve with time

and yes for some people makes completely no economical sense to go off grid
and yes lots of people are hyped and they think going off grid will be able with 2.00 0 euros or less

so yes every case needs to take down the numbers and see what he gains what he loose.

I just did the calculation with only the battery cost. There is also the cost of the pv panels, battery charger, DC to AC inverter along with cabling and fusing. So the up front cost will be much more than 3 times the cost of purchasing power from my utility. And a 200Ah battery may cost me only $300 today it will be more in 5 years. The costs keep adding up.

I am lucky because my power quality is pretty good. But the chance of it stopping is high during bad weather. Then I would use an emergency generator which will provide me much more power than a battery system for much less cost including the fuel to run it.

You may have a different situation with your electric cost and power quality but in my opinion you will still end up spending a lot more for a solar/battery system then just purchasing power from your utility.

[ANIKHTOS]

hello

For me, 876 kWh purchased from my utility at $0.12/kWh = $105. The cost of a 12volt 200 Ah battery ~ $300.

So just the battery cost is almost 3 times what I would spend purchasing that 876kWh or for that $300 I could have purchase 2500kWh at $0.12/kWh.

How do I save money generating my own power from batteries?

welll different people
in different locations
have different outcomes
while you pay 0,12 dollars per kw i have to pay 0,3 euro per kilowatt so that 34 cents at your country currency
while a battery just a very fast check 12v 200ah costs 289 euros 322 usd

so in my country the 322 dollars to buy the battery can buy me 947kw so do you see a difference????

while you say or me its 3 times more expensive for my side
its 8% more expensive from battery side

and thats how situation is right now
if tomorrow all the extra taxes you get in electric bill come to an independent bill
then cost will go to 0.12 euro per killowat given current prices

so if electric bill is only electric then situation here will be like the situation in your country

and in spain they talk to but a new law that taxes sun and effectively makes you go even in 20 years of operation
and i am talking for having solar panels selling energy to the grid 20 years to get even with life expectancy of panels 25 lol
also in the same law all off grid houses will have to get on grid!?!?! and pay an electric company

i do not know the quality of power in your country put here the quality sucks
and what sucks even more even if your things are toasted from the bad quality you can not sue the company to get
your items replaced by them
maybe in your county you can have liable the company but not in here
it is insane
yes it is
but thats the situation as it is now
maybe later the poco will be liable and thus the will provide better quality than the one we have now

and of course what it end ups is what you can afford to pay

i talk with people going off grid in greece and they say no i want to use my ac and i say to them okey
when was the last time you used it
they say 3 years ago
i can not afford to use it lol
another said and if i want to use a melding machine that consumes 10k what i will do
i ask him how often you use one
and he said never

you know we can start having hypothetical conversations or more realistic ones
yes i want to use ac but it i can not afford to pay it even when connecting to a poco i can not use the ac as an argument to stay on grid
and since that people are on pension their financial is not going to improve with time

and yes for some people makes completely no economical sense to go off grid
and yes lots of people are hyped and they think going off grid will be able with 2.00 0 euros or less

so yes every case needs to take down the numbers and see what he gains what he loose.

[SunEagle]

i do not live in usa
i live in Greece
and the country now is in mess

.....

are you know serious of how much energy takes to make a battery???
a 12 volt 200 ah battery takes how much energy?
which you are going to use for 5 years
lets say you use 40 ah per day that 480 watt per day thats 876kw in end of life

so according to you the battery will cost us 1314kw to make?????'

For me, 876 kWh purchased from my utility at $0.12/kWh = $105. The cost of a 12volt 200 Ah battery ~ $300.

So just the battery cost is almost 3 times what I would spend purchasing that 876kWh or for that $300 I could have purchase 2500kWh at $0.12/kWh.

How do I save money generating my own power from batteries?

[Sunking]

and as i said we end up paying 30 cent euro per kw
because of all the extras we have to pay with the electric bill

So what. Why do you want to pay 4 to 6 times more than that all up front in cold hard cash in 5 year increments?

What you are saying is foolish. Sure electricity is 4 times higher there than the USA, but so are the batteries and everything else it takes to make a solar system. In Greece for you to have a solar system to produce 10 Kwh per day if bought in the USA would cost you roughly $16,000 USD with $11,000 of that in batteries all up front in cash. That does not include thee extra $5000 to $7000 in other equipment and material to make it work. In about 5 years you get to buy another battery at even higher cost al up front in cash.

In Greece it will cost you several times more. You are looking at $60,000 to replace $4/day in electricity. Hope you are very rich and never need to work another day in your life. Otherwise batteries don't taste very good when you are hungry, and they don't work worth a damn keeping you warm and rain off your head. You might think we are giving you a hard time an you would be right to prevent you from doing something extremely stupid.

But if you insist, we will help you now that you know how foolish it is.

[ANIKHTOS]

If your total cost of grid power is upwards of $1-$2 per kWh, then it justifies doing a careful evaluation of the economics of battery stored PV power.
Right now there is nowhere in the US that has that high a cost, even Hawaii and Alaska.
(In some cases of remote areas where the "grid" power is provided by a cooperative using diesel powered generators, the cost can be above $.50.)

Less cost than that, it only might make sense if you also need to provide daily backup for an unreliable grid.

i do not live in usa
i live in Greece
and the country now is in mess

it is bankrupt
people without jobs
jobs with lousy money if you are lucky to have one
there is no social security in greece
you loose your job you get no support

and as i said we end up paying 30 cent euro per kw
because of all the extras we have to pay with the electric bill

i do not know the mentality in the usa or how much you consume but i am around 900kw per month or less
with the old fridge consuming around 1kw per day in winter time
so i need a new fridge to cut down the consumption

now for lights thank you led consumption is very low
low power computer helped to go down in consumption

so know i have to deal with fridge
then the cooking
and then i pull the plug off grid

are you know serious of how much energy takes to make a battery???
a 12 volt 200 ah battery takes how much energy?
which you are going to use for 5 years
lets say you use 40 ah per day that 480 watt per day thats 876kw in end of life

so according to you the battery will cost us 1314kw to make?????'

[inetdog]

If your total cost of grid power is upwards of $1-$2 per kWh, then it justifies doing a careful evaluation of the economics of battery stored PV power.
Right now there is nowhere in the US that has that high a cost, even Hawaii and Alaska.
(In some cases of remote areas where the "grid" power is provided by a cooperative using diesel powered generators, the cost can be above $.50.)

Less cost than that, it only might make sense if you also need to provide daily backup for an unreliable grid.

[Sunking]

so all this in mind per kw in my country is sold 0.3 euro or more

That means batteries will be just that much more expensive. You will still be paying many times more than buying it.

so can i ask why something i can buy today and cost x amount of money 5 years latter will cost more?

You are joking right? Batteries are a very mature product. It is called inflation. Anything you buy today will cost more 5 years from now.

Batteries are a product of energy. You cannot make a battery without a whole lot of energy. It takes a lot more energy to make a battery that it will ever be able yield over its lifetime. That simply means a battery like Hydrogen and many other carries of energy will always be a multiple of the SOURCE FUEL. In a Pb battery at best it takes 1.5 units of energy to make a battery that can only deliver 1 unit over its life time. So to just make the battery it cost 1.5 times in just energy. That does not count labor, materials, equipment cost, taxes, liability, insurance, delivery, and profit. One you add all that up you you are a 5 to 6 time looser. That means you can never obtain a ROI or EROI. It means you are throwing money and resources away. The world would be better off if you stayed on the grid. Go off the grid and both you and earth are loosers.

I will help you, but all your reasons going off grid is FALSE. Now that you know, I will help if you decide to throw money away. Hell I might profit from it. I have no problem taking your money from you. Do you?

I also have no problem and prefer to help you make smart decisions and keep your money in your pocket.

[ANIKHTOS]

That would be extremely foolish. Why do you want to pay 5 to 10 more for power than buying it from the POCO for the rest of your life? Answer that question..

Just in battery cost alone, not counting anything else, you are looking at around 60-cents per Kwh. A good 5 year battery will cost you around $1100 to $1200 for each Kwh of usable power a day. 10-cents worth. In 5 years it needs replaced at even higher cost. In 5 years you get 1825 Kwh out of the battery. That means in battery cost alone you are paying $1100/1825 Kwh = $0.6027/Kwh. That is roughly 600% more then you can buy it from the POCO.

Your friend was a fool, don't follow him over the cliff.

because in my country
with the bill we have to buy 2 3 times more in other fees
so it makes real sense to go off grid

so all this in mind per kw in my country is sold 0.3 euro or more

so can i ask why something i can buy today and cost x amount of money 5 years latter will cost more?
if you say inflation then i will also say that most probably the salaries will also go up
and also lifepo4 batteries go down in price
i bought a few small ones to play around with the new technology and i used them in custom flash lights with leds

now both leds and the batteries cost less
so why the battery cost will be worse??

also my friend has no option he is unemployed
so he used his last money to go off grid
if not done that the power company would cut the power anyway because he would not be able to pay the bill

so i do not think him as a fool
at list now
he has light to see in the night
he can watch television
he can use his computer to try to find a job
he can charge his telephone

if he had not done it what??
he was going to be like his sister living in an apartment without electricity?

his life is not the same as on grid
but at least he has not return to stone age
in my country because of the prices the crisis 2 million houses are cut off from the poco
and many more will follow

so depending your situation off grid maybe is the only choice that makes sense to do
also form a financial point

and you know i love maths
and i won maths competitions when i was in school
so all the time i am with a calculator calculating things in a ridiculous extend and detail

because of my personality i always want to have the max out of a situation

so no worries i have done the maths and i know the cost
2nd i know that i will not be able to build a system to have a life as when in grid
but at least i will have minimum level of quality that i will not go bellow

thats why the led testing the experiments with low voltage computers

most probably i will have money to buy only 2 solar panels and build a small pack to start with

but at least i will be able to be on Internet and talk here and there and have people telling me that i am stupid
and i should have stayed with poco
i prefer to be called idiot because at least i will have the possibility to be online so i can be called like that
so calculations say 5 years to break even with current prices
calculations were 1 year ago so maybe now it will break even faster
panels are cheaper batteries are cheaper

[SunEagle]

thank you all for the info now all are clear


i have a friend that went off grid but because of money problems
his solutions was the best i can do with the money i do not have
so his pack is different batteries manufacturer age and capacities making his pack
a solution of the desperate

i do not have the money to go off grid now
but i like to get informed and i am doing small steps towards it

The cost of generating your own power with batteries is many times what it would cost you for the same amount of electricity purchased from the Utility.

The only way your friend could save money by going off grid was to not use about 95% of the electricity he was paying for. That usually requires a major change in the way you live because there will be next to no electrical appliances.

[Sunking]

ultimate goal to go off grid.....
i have a friend that went off grid but because of money problems

That would be extremely foolish. Why do you want to pay 5 to 10 more for power than buying it from the POCO for the rest of your life? Answer that question..

Just in battery cost alone, not counting anything else, you are looking at around 60-cents per Kwh. A good 5 year battery will cost you around $1100 to $1200 for each Kwh of usable power a day. 10-cents worth. In 5 years it needs replaced at even higher cost. In 5 years you get 1825 Kwh out of the battery. That means in battery cost alone you are paying $1100/1825 Kwh = $0.6027/Kwh. That is roughly 600% more then you can buy it from the POCO.

Your friend was a fool, don't follow him over the cliff.

[PNjunction]

For lifepo4, it is pretty simple if you have multiple cells:

PARALLEL the individual cells to build up your desired capacity first.

The SERIES connect these "groups" of paralleled cells to get your desired nominal voltage. You now have a "battery" of cells.

This helps to keep them in balance, once they are charged properly to do so. Follow guidelines as mentioned above about not doing simple "ladder" connections for charge / discharge, but do the "diagonal" or other such configuration to avoid charging / discharging solely from the end of the bank.

[ANIKHTOS]

thank you all for the info now all are clear

i am doing baby steps

first step was buy dc power supply for computer
actually bought 3 of them
then bought an atom board so i can build a low power pc and a battery
and i run the computer from the batter successful

then i bought leds just the led and i build the lamb myself
so i need a dc converter to use
second phase a battery 12 volt and a dc dc converter

and start replacing lights at home

ultimate goal to go off grid

i start by changing things inside the house one by one lowering the power drain and switching everything in dc

so now i am looking for the batteries
technologies connections capacities

i have a friend that went off grid but because of money problems
his solutions was the best i can do with the money i do not have
so his pack is different batteries manufacturer age and capacities making his pack
a solution of the desperate

i do not have the money to go off grid now
but i like to get informed and i am doing small steps towards it

[inetdog]

That is what you call your 2p2s. It is the Alternative Connection shown below.






Already covered this, Connect batteries in Series and avoid parallel strings unless neessecary. Reason is simple you cannot BALANCE the Battery internal resistance or distribution resistances to keep all currents equal in parallel arrangements. That means there is always one string doing most of the work wearing itself out prematurely. Professional installations can parallel batteries with great success, but you CANNOT because you do not have the money, knowledge, or resources. Pro's use engineered solid copper buses arranged in such a fashion that equalizes circuit resistance so all strings charge charge and load equally. If you must Parallel to obtain the desired capacity limit it to just only 2 parallel strings, or use a Ladder Connection, but with Ladder you need a way to monitor every battery including Specific Gravity.

Just to avoid potential confusion among other readers of the thread, the illustrated connections are 3S2P and 2P3S respectively. The OP was looking for a four battery configuration, but adapting the diagrams given (by removing two batteries from each) should not be to intellectually challenging.

One of the problems with a ladder connection is that the two batteries in each "rung" of the ladder must be well matched in charge before the connection is made.
With the series first connection that is still an issue, but it is equally important to match the SOC of each of the batteries in the series string before making the initial connection. Otherwise you will end up doing much more initial equalization than necessary, stressing the batteries which started with a high SOC.