Solar question

[Operastone]

Hi everyone,
I have recently installed an off grid system at home.It comprises of 6 panels each of 200watts,A 24v inverter+charge controller, and 4 150ah batteries.
Now the system is 1200watt during day I need 800 watt constantly for 8 hours (the sun shines for 10 hours)
But the inverter shuts down whenever I apply more than 300w load and gives low battery voltage error.
I hooked the multimeter and it showed batteries receiving only 10A from panels which is far less than the solar capacity.I have checked individual panels and each of them produced (7.4A and 28-29v).i don't care if batteries don't give me enough backup at night I just need solar to produce 800w energy for my day usage.And my question is do the off grid systems need batteries fully charged first and then supply powers or they can work like panel>battery>load without charging the battery?
I will be greatful if anyone of u solve my problem.
Thanks in advance.

[Wy_White_Wolf]

1. What charge controller?

2. How are the panels wired?

3. Sun Shining is not the same as solar insolation. I don't know your location but most likely your setup will never support that load.

[Sunking]

So what is the problem?

What you describe is completely normal for a grossly undersized system. To start with your battery is only 1/4 the size it should be. At 24 volts you need at least a 1300 AH with a minimum 3400 watts of panel wattage and 2- 80 amp charge controllers. From the start this should have been 3000 to 4000 watt, 48 volt battery system a minimum 700 AH battery, and a 80 amp MPPT Charge Controller.

[Operastone]

So 600ah for 1200watt system is not enough? Also can't I get direct load of 800w without charging he batteries?
If not please guide me what things I require for getting 800w power during the day time I don't need power as backup because I need electricity only from 7am to 5pm. I just want to attach lesser batteries because I don't need them
Also from understanding of your previous post I think u are saying that I should use 12v system with 1500w inverter(currently I have 3000w) but the problem is my panels are 24v

[mschulz]

So 600ah for 1200watt system is not enough? Also can't I get direct load of 800w without charging he batteries?
If not please guide me what things I require for getting 800w power during the day time I don't need power as backup because I need electricity only from 7am to 5pm. I just want to attach lesser batteries because I don't need them
Also from understanding of your previous post I think u are saying that I should use 12v system with 1500w inverter(currently I have 3000w) but the problem is my panels are 24v

For your power needs, Sunking gave you the answer in his post above.

For your 24 volt panel issue - read up on MPPT vs PWM charge controllers and it will make sense why MPPT cost more. Your MPPT will take higher voltage from your panel and convert it to your specific battery voltage.

[SunEagle]

So 600ah for 1200watt system is not enough? Also can't I get direct load of 800w without charging he batteries?
If not please guide me what things I require for getting 800w power during the day time I don't need power as backup because I need electricity only from 7am to 5pm. I just want to attach lesser batteries because I don't need them
Also from understanding of your previous post I think u are saying that I should use 12v system with 1500w inverter(currently I have 3000w) but the problem is my panels are 24v

Depending on where you live you will not get enough usable sunlight to generate 800 watt for 8 hours. You might get 5 to 6 hours of usable sunlight but not 8. To cover you during those lower sun power hours you add batteries.

But you need double that 600Ah of batteries and about 3500 watts of solar panels to feed your 800 watt load.

What make and model are your batteries. I am not sure how you can get a 24volt 600Ah system using 4 x 150Ah batteries. If they are 12volt batteries then you really only have a 24volt 300Ah system which is still too small for your load requirements.

Start at the begining and give us the make and model of your panels, charge controller, batteries and inverter along with how you have the system wired.

[Wy_White_Wolf]

so 600ah for 1200watt system is not enough? Also can't i get direct load of 800w without charging he batteries? no, you have a 8000wh load and the system is too small to support that.

if not please guide me what things i require for getting 800w power during the day time i don't need power as backup because i need electricity only from 7am to 5pm. I just want to attach lesser batteries because i don't need them you're assuming the panels put out full power all the time. They don't. Panels only put out full power under ideal conditions. If you set them up to produce maximum power at noon then at 7am the sun is at a 60 degree angle to the panels. You'll be very lucky if they produce 25% of there rated power at that time. Also 7am to 5pm is 10 hours not 8.

also from understanding of your previous post i think u are saying that i should use 12v system with 1500w inverter(currently i have 3000w) but the problem is my panels are 24v i don't know were the 12v came from but your panels are not 24v panels. They are intended to be grid tie panels. 24v panels need to have a vmp of about 36v to fully charge a 24v battery bank. You only have 29v. If you have them all wired in parrallel that is why you are only seeing 10 amps of charging. You need to wire them in a 2x3 or 3x2 configuration and use an mppt controller.

see above

[paulcheung]

Hi everyone,
I have recently installed an off grid system at home.It comprises of 6 panels each of 200watts,A 24v inverter+charge controller, and 4 150ah batteries.
Now the system is 1200watt during day I need 800 watt constantly for 8 hours (the sun shines for 10 hours)
But the inverter shuts down whenever I apply more than 300w load and gives low battery voltage error.
I hooked the multimeter and it showed batteries receiving only 10A from panels which is far less than the solar capacity.I have checked individual panels and each of them produced (7.4A and 28-29v).i don't care if batteries don't give me enough backup at night I just need solar to produce 800w energy for my day usage.And my question is do the off grid systems need batteries fully charged first and then supply powers or they can work like panel>battery>load without charging the battery?
I will be greatful if anyone of u solve my problem.
Thanks in advance.

800 watts continues power for 10 hours is a lot of power for off grid. good thing is that the demand is during 7 am to 5 pm. I don't know where you live, but if you are some where similar to where I live, like Jamaica, you can get 3000 watts panels, aim 1500 watts to Southeast side to catch the morning sun and the other 1500 watts to the Southwest side to catch the afternoon sun if you live on Northern Hemisphere. if not do Northeast and Northwest instead.

Off grid if you don't have grid to backup you need a generator to charge the battery when the sun is not shine for a day. If you willing to use the generator often then you can get a 600 amp hours 24 volt battery bank a midnite classic 150 charge controller.