Battery Bank

[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

[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.

[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.

[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.

[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

[noshali]

You will find that standard car starting batteries, will not last more than a couple months in deep cycle service. They will fail much sooner than Deep Cycle batteries. So, you will be taking them back for warranty replacement, and after the 2nd time, the store will likely lock you out.

12V batteries only have 3 interconnect cables. If you use 2V batteries, you will have 23 interconnect cables to build, bolt to batteries, and keep clean.

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

[Mike90250]

.....

BTW I am in Pakistan. Yes they play golf here but deep cycle batteries are considered a luxury...most people use the standard crank car batteries to get by.

Thanks

You will find that standard car starting batteries, will not last more than a couple months in deep cycle service. They will fail much sooner than Deep Cycle batteries. So, you will be taking them back for warranty replacement, and after the 2nd time, the store will likely lock you out.

12V batteries only have 3 interconnect cables. If you use 2V batteries, you will have 23 interconnect cables to build, bolt to batteries, and keep clean.

[noshali]

Sorry....I tend to ramble and assume that folks know what is inside my head. My wife complains about the same thing...
What I meant to say was that once I get the 200ah bank..I will not be able to add batteries for some time as after this investment I would have spent all I could on my solar project. Maybe add panels but want to be done with batteries for sometime.

My question is that now I have 2 UPS. Is it better to have 8 100ah batteries in 48v config or is it better to have 4 200ah batteries 48v. Lets say down the road I add more panels and another CC....I could take 4 batteries from the existing bank of 8 and create 2 100ah banks. Is that better or is it better to feed 2 cc to one 4 battery bank of 48 volts. What I am afraid of is that if I add another cc and panels (lower cost than batteries) then would it be a problem to have 2 cc feed one bank.

BTW I am in Pakistan. Yes they play golf here but deep cycle batteries are considered a luxury...most people use the standard crank car batteries to get by.

Thanks

[mapmaker]

Create 2 strings...one for each UPS but have only ONE charge controller that will feed both strings.
thanks

That won't work. If you hook up a charge controller to two strings of batteries, you will be putting those two strings in parallel.

3120 watts of panels is a lot for a 165 or 200 ah battery bank.

Where are you located that you cannot find 6 volt batteries? I think 6 volt golf cart batteries are the most widely available batteries.

I am too confused by your situation to offer much design help. You say you can't afford to add batteries, but then you plan to have two strings of batteries.

Perhaps you should abandon this confusing thread and start over with a clear description of what you have and what you hope to accomplish with an upgrade. Then the forum members can give you their thoughts on how to accomplish your goals.

--mapmaker

[noshali]

6 volt not available....after doing some research 2 volts might be older stock hence cheaper. 165ah bank will go.
Now please help me with this.
I recently added a APC UPS to my setup. I really cant afford adding batteries. The need to add the UPS was to split the load. So now I have 2 5000va UPS connected to the same 165ah bank with 3120 watts solar panels and a xantrex 60 amp cc.
Now I want to replace the bank with 200AH bank. SHould I use 8 100ah batteries or 4 200AH batteries???? Create 2 strings...one for each UPS but have only ONE charge controller that will feed both strings.
thanks

[mapmaker]

Ok..finally found a dealer that has 200ah batteries. Still over my budget but worth considering. He gave me 2 options for 48 volts bank.

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

What are the pros and cons? Please advise so I can make an informed decision. Also, what is the best planning in case I need to add AH to the bank later as my needs increase.

I am surprised that the 24x2 is cheaper. What batteries are these? Also, did you consider 8 x 6 volt batteries? These are usually the cheapest.

Also, you already have 4 x 12 volt 165 ah batteries. Are you planning to use them in addition to the 200 ah batteries you are looking at?

--mapmaker

[noshali]

Ok..finally found a dealer that has 200ah batteries. Still over my budget but worth considering. He gave me 2 options for 48 volts bank.

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

What are the pros and cons? Please advise so I can make an informed decision. Also, what is the best planning in case I need to add AH to the bank later as my needs increase.

thanks

[Mike90250]

Thanks...I posted another question that no one answered and I am lost. If you would be kind enough to have a look and advise if possible.

maybe post again to that thread. or maybe it's a question that has no valid answer.

[inetdog]

Thanks...my xantrex charge controller asks for it....the default value was 440ah.

I believe that the Xantrex, without explaining it to you, uses the AH value you enter to set the end-current/end-amps value used to terminate the Absorb phase or maybe to otherwise determine the length of time for Absorb. So while the real value is a good first step, you may later actually want to deliberately fudge this number to get the performance you want.

[FloridaSun]

Thanks...I posted another question that no one answered and I am lost. If you would be kind enough to have a look and advise if possible.

if possible... I rarely post tech answers here as their are so many more on this forum more qualified than I.
Be patient. The pros do have other things to do besides sit here and answer questions. Amazing really how much time those pros do take time out of their everyday life to help us.