How do i power my house on batterys

[marko]

What sort of batteries are these?

Are they sealed lead acids or are they flooded?

Generally it's all right to charge batteries to higher voltages for a short length of time, in fact most battery manufactures recommend it for fast charging.

You're right about the the voltages being added together when you connect them in series.


Why not connect all those batteries in series to get 108V?

You can buy large inverters that work from 100VDC.

Obviously at this voltage you need to be careful.

these bats are 6v yuasa endurace 160a,i did look at a 120v dc invertor but im not that sure with all that voltage being a diy man

 

[tcmtech]

I have seen several people run off of batteries and actually doing the batteries then generator then back to batteries is the most efficient way of getting the most out of your fuel usage and generator life.

The biggest system I have ever seen was a guy I sold 96 4 volt 300 Ah batteries too.
(I ran his bank out of $100 bills when I cashed the check too!)

His system was 24 volt and originally ran on 12 6 volt 200 Ah golf cart batteries connected as a series/ parallel. Four batteries in series to get 24 volts and then three sets like that in parallel. The total capacity was 24 volts 600 Ah.
Each set of four batteries had a 100 amp fuse so if one bank went bad it just blew that fuse and let the other two sets still run.
His home electrical system was similar to what your talking about. He had one smaller sized modified sine wave inverter that covered all the lighting duty and was always on. A second unit was dedicated to the well pump and some of the higher load devices in the shop. That one cycled on as needed.
There was a third one that ran the kitchen stuff and also was set up to cycle at certain times of day or could be manually ran also, I think.

I dont see why your entire system could not be set up similar. I would however set up the battery bank as a set of 9 series parallel units with a 50 -100 amp fuse or breaker for search set. That way your total amp draw per battery is low and thus the discharge time rate will be at its most efficient.
However, charging a 12 volt 2880 Ah (30+ KWh usable) battery bank will take a fair sized generator and battery charger! Factoring in recharge efficiency losses you would need a charging system that could supply at least 4 kw at 14.4 volts (280 amps) for around 10 hours if the batteries are run down.

But over all your system has great potential and if properly done It should be easy to work with and maintain. Plus adding solar or wind or alternative fuel charging systems is not hard.

A propane powered gen set is far cheaper to run and lasts far longer than a gasoline powered one too.
For the high amp low voltage charging using 4 to 6 100 amp alternators run off a small car engine at low RPM, 900 - 1200 RPM engine speed with a 4:1 belt speed increase at the alternators, will save you fuel and get an incredible running life if propane powered.
I have seen two rigs set up that way before and both owners said they were far more fuel efficient than a small engine and the expected running life was in the 10's of thousands of hours!
Plus both used the engine and exhaust heat to make hot water for heating their homes and hot water heaters. That makes the fuel use during charging cycles even more efficient when the engine waste heat is captured and used in a positive and constructive way.

The set up cost and time involved will be more to do it this way but the added gains will make the long term use far more cost effective.

Just somethings to think about.

 

[nickelflippr]

most of my appliances are lpg the fridge freezer is not but A rated for energy,this was the problem with my gene useing all that power just for maybe a tv or the odd light my main concern was keeping the fridge running 24/7

Off load the fridge freezer to LPG and the generator run time drops like a rock. I have this same argument with a friend of mine about his off grid cabin up in the woods.

Hero999 said:

Are they sealed lead acids or are they flooded?

Why not connect all those batteries in series to get 108V?

You can buy large inverters that work from 100VDC.

Here's the data sheet on the **broken link removed** battery. Looks to be an AGM style of battery. I like your original idea of 48V grouping, this is more common or standard? The idea behind the one inverter scheme is using less low gauge copper and saving an extra distribution panel for each individual inverter.

 

[marko]

I have seen several people run off of batteries and actually doing the batteries then generator then back to batteries is the most efficient way of getting the most out of your fuel usage and generator life.

The biggest system I have ever seen was a guy I sold 96 4 volt 300 Ah batteries too.
(I ran his bank out of $100 bills when I cashed the check too!)

His system was 24 volt and originally ran on 12 6 volt 200 Ah golf cart batteries connected as a series/ parallel. Four batteries in series to get 24 volts and then three sets like that in parallel. The total capacity was 24 volts 600 Ah.
Each set of four batteries had a 100 amp fuse so if one bank went bad it just blew that fuse and let the other two sets still run.
His home electrical system was similar to what your talking about. He had one smaller sized modified sine wave inverter that covered all the lighting duty and was always on. A second unit was dedicated to the well pump and some of the higher load devices in the shop. That one cycled on as needed.
There was a third one that ran the kitchen stuff and also was set up to cycle at certain times of day or could be manually ran also, I think.

I dont see why your entire system could not be set up similar. I would however set up the battery bank as a set of 9 series parallel units with a 50 -100 amp fuse or breaker for search set. That way your total amp draw per battery is low and thus the discharge time rate will be at its most efficient.
However, charging a 12 volt 2880 Ah (30+ KWh usable) battery bank will take a fair sized generator and battery charger! Factoring in recharge efficiency losses you would need a charging system that could supply at least 4 kw at 14.4 volts (280 amps) for around 10 hours if the batteries are run down.

But over all your system has great potential and if properly done It should be easy to work with and maintain. Plus adding solar or wind or alternative fuel charging systems is not hard.

A propane powered gen set is far cheaper to run and lasts far longer than a gasoline powered one too.
For the high amp low voltage charging using 4 to 6 100 amp alternators run off a small car engine at low RPM, 900 - 1200 RPM engine speed with a 4:1 belt speed increase at the alternators, will save you fuel and get an incredible running life if propane powered.
I have seen two rigs set up that way before and both owners said they were far more fuel efficient than a small engine and the expected running life was in the 10's of thousands of hours!
Plus both used the engine and exhaust heat to make hot water for heating their homes and hot water heaters. That makes the fuel use during charging cycles even more efficient when the engine waste heat is captured and used in a positive and constructive way.

The set up cost and time involved will be more to do it this way but the added gains will make the long term use far more cost effective.

Just somethings to think about.

Thanks very much for the info i shall have a good read and get back to you

 

[marko]

Off load the fridge freezer to LPG and the generator run time drops like a rock. I have this same argument with a friend of mine about his off grid cabin up in the woods.

Hero999 said:

Here's the data sheet on the **broken link removed** battery. Looks to be an AGM style of battery. I like your original idea of 48V grouping, this is more common or standard? The idea behind the one inverter scheme is using less low gauge copper and saving an extra distribution panel for each individual inverter.

thanks for the info

 

[Willbe]

got 6 volt yuasa 160 amp batts and 18 in total
17,000 watt-hours of energy stored
and charging these will take about
28,000 watt-hours
Are they deep cycle batts?


my idea is to power my house for maybe 2-3 days

So your house takes 6 kwh each 24 hrs = 250 w, about 1/4th of average house power.

the third day my generator would kick in and run the house for say 8 hours but also recharge the batts,then go back over to batt power

So your generator puts out ~28 kwh in 8 hrs = 3.8 kw (assuming the batteries won't be damaged by charging that fast) to power the house and charge the batts.

i have been told if i run in paralel
parallelling this many batteries with current sharing would be a nightmare.

my 2 invertors at present are 12 v input then i will have to series my 2 6 volts up to give me 12volts am i right in thinking i will only get 160 amps and not 320 doing this , Iwould like to use a bank of 8 batts to run the say 3000 inverter and then 4 batts to run the 1500 inverter and the same with the last inverter leaving me two batts as spares can you please please please advise me maybe a diagram i am looking to get the best useage from my batts time wise i know this will depend on what i use but the only appliance that will run 24 hrs is the fridge which is A rated, thank you

18 ea. 6v batteries could almost be charged in series with 120vac rectified.
With many relays driven by switching logic you might get away with this.

 

[marko]

18 ea. 6v batteries could almost be charged in series with 120vac rectified.
With many relays driven by switching logic you might get away with this.

hi they are endurance deep cycle batts ,this is all new to me as you can see and im trying to wing it with help from forums and internet, im trying to do this as cheap as poss my gene is 8 kva and i have no chargers yet
i am at a lost at moment ,head scratching,and brain ache,i am trying to get some sort of diagram which i can follow at the mo ive got the gene,18 bats,and to 12v1500 inverters maybe a 48v 3000 inverter by the end of the day, ive already brought a 48v charger 2 amp which i dont think now is any good for anything

 

[dknguyen]

It doesn't matter whether the generator is running for 2-3 days or 7 days (unless you are unwilling to start the generator so you leave it running ALL the time). But it is much more efficient to run the generator whenever you need it then, then to run it for a shorter time to charge batteries so you don't have to start up the generator.

But why don't you just use solar or something like that since the power use is so infrequent compared to the time you have to charge?

 

[Willbe]

they are endurance deep cycle batts
my gene is 8 kva
gene,18 bats,and to 12v1500 inverters
maybe a 48v 3000 inverter by the end of the day,
ive already brought a 48v charger 2 amp which i dont think now is any good for anything

How much elec. energy does your house take, yearly?
Diagrams come after all the design spec's are nailed down and purchases come after that.
With top down design, the most abstract, general stuff is firmed up first, then the next level of detail down, and so on until you come up with a parts list.
With many ways to get your 250w, using spreadsheets will probably allow you to find a minimum cost implementation of this design.

As to saving money on fuel,
1 Therm of energy can be had from approx. 0.71 gal of fuel oil, 0.77 gal of gasoline, 100 cubic feet of natural gas, 1.1 gal of propane, 29 kwh of elec heat, 8.4 kwh of heat pump heat, 14# of wood or 12 billionths of a pound of radioactive material, and average solar insolation in kilowatt-hours per square meter per day for CA is 6.

 

[marko]

How much elec. energy does your house take, yearly?
Diagrams come after all the design spec's are nailed down and purchases come after that.

Thats something i dont know its a new build,the only thing that runs 24/7 is the fridge freezer,all i know is that i have 450w in all the lights in the house,ideal would be the fridge to stay on always the tv at night and the odd light, daytime time running would only consist of the fridge and maybe the tv or radio.as for the washing machine i was going to use the gene for when this was used,its being able to have lights at night if they are needed instead of running the gene to power maybe two lights and a tv

 

[Willbe]

Thats something i dont know its a new build,
the only thing that runs 24/7 is the fridge freezer,
all i know is that i have 450w in all the lights

Fridge = 1200 w-h/day = 400 kwh/yr.
https://www.electro-tech-online.com/custompdfs/2009/05/Power-table.pdf

<450w 8 hrs/day = <1300 kwh/yr
So 400-1700 kwh/yr = 50-200w, continuously.
17,000 w-h/[50-200 w] = 240-85 h before the batts need recharging.

 

[Hero999]

Hero999 said:

Here's the data sheet on the **broken link removed** battery. Looks to be an AGM style of battery. I like your original idea of 48V grouping, this is more common or standard? The idea behind the one inverter scheme is using less low gauge copper and saving an extra distribution panel for each individual inverter.

Yes 48V is a standard voltage, it's used for telecommunications equipment and represents a good compromise between conductor size and safety.

Please note that the higher the current draw the lower the Ah rating will be - take note of the tables on the datasheet.

 

[marko]

Yes 48V is a standard voltage, it's used for telecommunications equipment and represents a good compromise between conductor size and safety.

Please note that the higher the current draw the lower the Ah rating will be - take note of the tables on the datasheet.

thanks for the info you have been most helpfull,i will put something down onpaper and work it out,no doubt i will get stuck somewere thanks