Battery Bank

[mapmaker]

I wasn't.planning on using the regular car batteries.I will be using deep cycle batteries.
Please advise on the question posted for making the right choice on the bank. Buying 100ah vs 200ah

How can we possibly advise you on batteries? You haven't told us much about them other than their ah capacity. How about a brand and model?

Also, when designing a system we start with understanding the loads, then choosing a battery and system voltage, then choosing electronics and solar panels to meet the needs of the battery.

If you asked us to choose a vehicle for you we would need to know what you plan to carry in the vehicle... do you need a motorcycle or do you need a dump truck? It is the same for batteries... It is impossible for us to choose a battery for you without knowing what your needs (loads) are.

--mapmaker

[Sunking]

4x12 volts 200ah batteries or 24x2 volt 200ah batteries. the 24x2 option is cheaper.

24 x 2 is th ebatter option but 2 volt 200 AH batteries I have never seen before. It is not normal because 2 volt cells usually start at around 1000 AH. I cannot imagine what purpose 2 volt 200 AH serves.

What wattage are your panels? Assuming you are using a MPPT charge controller you do not want to exceed 1300 watts with such a small 48 volt battery if they are Flooded Lead Acid.

As stated no one can really answer your question because you have provide no details on daily watt hour usage and location. You start with that, then design a system to meet the requirement. Doing otherwise is guaranteed to fail.

[noshali]

Thank you all of your help.
I live in Pakistan where there is shortage of commercial power and during extreme weather the electricity is gone for 12 hours a day. So it usually is on for one hour and off for one hour. Pakistan is 230 volt 50hz
I looked at my load and the way I did that was using a amp meter on the output of my ups. I turned everything on for peak load and it came to around 8 amperes or 1800 watts. This does not include the AC which is 10 amps or 2300 watts. AC is on commercial power and not connected to solar.
I also have a 13KW backup generator.
My goal is to have 24 hour electricity with a combination of commercial, generator and solar.
I started with 6 195 watt canadian solar panels and a xantrex 60amp mppt charge controller. connected them to my APC 5kva UPS. Left the commercial power on as the load was more. I would get around 7kwh daily from the panels. I noticed that since power came back every hour...the ups charger would take over and the cc would basically go to ZERO. I wanted to add my AC to the setup also so added another 10 195w panels. the max I can harvest from my cc is 60 amps @ 48 v = 2880 watts. Now I turn off the commercial power on my UPS from 9-5 and get around 13kwh and the batteries are also charged. I turn on the power at 5. I programmed the AUX out of my CC to monitor the battery voltage and turn on the 12volt out when battery voltage hits 48v (50% juice left). The relay turns on the switch for commercial power and also turns the generator automatic. If there is comm power then the generator does not start and charging starts to happen. This also works if during 9-5 it is raining or cloudy. With this setup I have 24 hour electricity and my generator runs for around 2 hours everyday at night to cover the shortfall.
I have added another 5kva UPS and will put the load of one AC 10amps on it and connect it to this setup. It will have relays that will switch it to commercial power when not sunny. I feel that my batteries are getting old...I like most people here am using crank batteries and want to switch to deep cycle batteries.
As I mentioned earlier that it is a luxury here and very few people import deep cycle batteries (none are manufactured here)
I have a choice of the following 2 batteries:

http://en.naradapower.com/Products/SLA/battdata/pdffiles/ACME.F/12NDF155.pdf

http://en.naradapower.com/Products/SLA/battdata/pdffiles/MP/6-GFM-200M.pdf

The 155 ah is not available in 100 or 200 ah
The 200 ah one is available in 100 150 and 200ah
Now if you had to choose with the limited budget and choice which one would you go for. If bigger the better then would I be better off with 8 100 ah or 4 200 ah.
Do let me know if you have any suggestions or concerns. I had to do all this on my own as very few people know much about solar. My goal is to harness the maximum during the day and run load other than the AC at night using commercial/batteries. Want to avoid using the generator as very expensive.

thanks.

[FloridaSun]

the max I can harvest from my cc is 60 amps @ 48 v = 2880 watts.

Keep in mind the recommended maximum charging current limit of the batteries you choose. The limit is 50A on the 6-GFM-200M battery.

[Naptown]

The 4 200ah batteries in one series string would be much better than 2 parallel strings of 4 100ah batteries
And will last longer too