What is the difference between 4x 200Ah or 8x 100Ah AGM for 48v 200Ah?

[Little Ray]

I am not saying this would be the case, but If you could purchase 100Ah or 200Ah in the same design from the same company, comparable in price including freight.
What are the advantages and disadvantages between using 4x 200Ah or 8x 100Ah AGM for 48v 200Ah?

Ray

[Mike90250]

You want to design for the least number of cells to reach your capacity,
Lead Acid cells produce roughly 2 volts. Cells are stacked to often create 6V batteries.
to increase capacity (amp hours) and still be able to lift a battery, sometimes a single 600ah cell (2V) or just two 400ah cells (4V) are used to avoid parallel strings

Until you have some solar experience and have ruined your first set of batteries, don't get AGM at first, any mistakes kill them

[Little Ray]

You want to design for the least number of cells to reach your capacity,

My assumption was that you would choose the Battery of required Capacity!

I ask, because people keep answering questions, by re-writing them.

Ray

[SunEagle]

IMO the 4 x 200Ah wired in series to create a 48v 200Ah system is a better design then the 8 x 100Ah because you eliminate the issues of parallel wiring.

The problem I see with those 12v 200Ah batteries is that they will be very big and heavy.

As Mike states it is better to used lower voltage / high Ah rated cells to create your system.

[Wy_White_Wolf]

My assumption was that you would choose the Battery of required Capacity!

I ask, because people keep answering questions, by re-writing them.

Ray

Many times we half too because the OP doesn't supply all relevant info needed. In this case battery voltage.

If they are both 12v batteries then the 200AH batteries would be better as they would allow a single string and 1/2 the cells to maintain/check. If the 100AH are 6V and the 200AH are 12V I feel the 200AH would be a better choice because of fewer connections. If the 200AH are 6V there is not enough of them to make a 48V bank.

Also are they both the same type of battery?

WWW

[Little Ray]

IMO the 4 x 200Ah wired in series to create a 48v 200Ah system is a better design then the 8 x 100Ah because you eliminate the issues of parallel wiring.

The problem I see with those 12v 200Ah batteries is that they will be very big and heavy.

As Mike states it is better to used lower voltage / high Ah rated cells to create your system.

Thanks for your reply,

As you point out, choosing the 12v battery for the 200Ah required, reduces the complexity.
This is one of many examples where the supplier is more interested in a sale then the buyers need.

I have not done any research yet, to know what an average or high price might be for 12v AGM.
Weight or physical size is not a problem, were you referring to the 12V 200AH SunStone?

We can normally afford local heavy shipping here in Aus.

SunStone 12V 200AH AGM
http://lanplus.com.au/index.php?rout...&product_id=69


-----------------------------

As Mike states it is better to used lower voltage / high Ah rated cells to create your system.

Are there any alternative for 2v cells making the Bank for around the price of 12v 200AH Batteries, or is it just better if you can afford 2V cells.
Would they come lose or in a 12v casing? Or even 48v casing?

Ray

[SunEagle]

Thanks for your reply,

As you point out, choosing the 12v battery for the 200Ah required, reduces the complexity.
This is one of many examples where the supplier is more interested in a sale then the buyers need.

I have not done any research yet, to know what an average or high price might be for 12v AGM.
Weight or physical size is not a problem, were you referring to the 12V 200AH SunStone?

We can normally afford local heavy shipping here in Aus.

SunStone 12V 200AH AGM
http://lanplus.com.au/index.php?rout...&product_id=69


-----------------------------



Are there any alternative for 2v cells making the Bank for around the price of 12v 200AH Batteries, or is it just better if you can afford 2V cells.
Would they come lose or in a 12v casing? Or even 48v casing?

Ray

If you check on the Trojan or similar FLA type batteries you can see that they come in multiple voltages and Ah ratings. A 2v would be self contained thus making it lighter that a 12volt battery.

Since you only need 200Ah system you might find 6volt batteries in that AH rating so you could use 8 wired in series for a 48volt system.

Based on the information I have found an FLA battery usually costs less than an AGM type and should last longer.

[Sunking]

First rule is never ever use parallel battery arrangement unless absolutely necessary to achieve a desired AH capacity. or in rare cases redundancy for maintenance. In a stationary applications like solar,, those conditions rarely ever exist. You can get 4000 AH cells. Parallel cells in a daily cycle operation just shortens the cycle life significantly in half. Bad move.

Be careful what you ask for. AGM cost twice as much and last half as long as FLA. That makes them roughly 400% higher long term cost. So you had better have a darn good reason to justify the cost.

AGM do have a place in solar. Example are where spills cannot be tolerated like aircraft. That is what AGM was invented for. Unusual mounting orientation like on their side, Extreme cold environment at -40 (not Aus), or where very high charge/discharge rates are required.

[inetdog]

.... or where very high charge/discharge rates are required.

Little Ray: And one example of that is high latitude sites that only get 2 sun hours in Winter.
You have to be able to charge at a high rate while the sun is shining to get you battery bank back even close to recharged, And you may still need to use a generator. When you charge with a generator you will get better economy from a higher load for a shorter time, even though the total watt-hours may be the same.

[Little Ray]

If you check on the Trojan or similar FLA type batteries you can see that they come in multiple voltages and Ah ratings. A 2v would be self contained thus making it lighter that a 12volt battery.
Since you only need 200Ah system you might find 6volt batteries in that AH rating so you could use 8 wired in series for a 48volt system.
Based on the information I have found an FLA battery usually costs less than an AGM type and should last longer.

I have just started looking at batteries, and familiar with Lead Acid but keep hearing AGM.
From what I am reading, FTA is still the Fixed Solar Staple.
Why are so many people in the industry pushing to sell you AGM.

Will do some study on FTA costs and working life.

Thanks to everybody who contributed.

[SunEagle]

I have just started looking at batteries, and familiar with Lead Acid but keep hearing AGM.
From what I am reading, FTA is still the Fixed Solar Staple.
Why are so many people in the industry pushing to sell you AGM.

Will do some study on FTA costs and working life.

Thanks to everybody who contributed.

My guess is that there is a higher profit margin selling AGM instead of FLA type batteries.

Also a lot of off grid systems use some type of cabinet to house the batteries. Using AGM type allows them to install the batteries on their side which makes it easier to check terminal voltage if they are all facing you. You can't do that with an FLA type.

[Sunking]

Why are so many people in the industry pushing to sell you AGM.

Read my last post and follow the money.

AGM cost twice as much and last half as long as FLA.

[Mike90250]

........
I ask, because people keep answering questions, by re-writing them. Ray

Sometimes, if the question is poorly phrased or just "wrong" we try to answer the best we can.

[Little Ray]

My guess is that there is a higher profit margin selling AGM instead of FLA type batteries.

Also a lot of off grid systems use some type of cabinet to house the batteries. Using AGM type allows them to install the batteries on their side which makes it easier to check terminal voltage if they are all facing you. You can't do that with an FLA type.

I had my own opinion about the aggressive marketing of AGM batteries in Australia which is much the same.
Australia is controlled by energy suppliers and generators.

I contacted Tesla when they announced the Manufacture of off-grid Powerwall, inquired about availability and filed document of interest with distributing off-grid powerwall.
Short story, Tesla has hooked up with the local Australia electricity supplier Origin Energy.
Tesla reneges on agreement in good faith, I am contacted by installers that ask where my grid connected system is to be installed?

In Australia, everybody is connected to Grid by Market installers and Companies who are incentivized and subsidies by Government, controlled by Energy Market.

The only people who buy solar batteries in numbers are Off-road Campers, and the AGM are generally better for purpose if you could afford it.

That was my thoughts.

Ray

[SunEagle]

I had my own opinion about the aggressive marketing of AGM batteries in Australia which is much the same.
Australia is controlled by energy suppliers and generators.

I contacted Tesla when they announced the Manufacture of off-grid Powerwall, inquired about availability and filed document of interest with distributing off-grid powerwall.
Short story, Tesla has hooked up with the local Australia electricity supplier Origin Energy.
Tesla reneges on agreement in good faith, I am contacted by installers that ask where my grid connected system is to be installed?

In Australia, everybody is connected to Grid by Market installers and Companies who are incentivized and subsidies by Government, controlled by Energy Market.

The only people who buy solar batteries in numbers are Off-road Campers, and the AGM are generally better for purpose if you could afford it.

That was my thoughts.

Ray

Based on your input it sounds about right. AGM seems to be more desirable to purchase there which makes it harder to sell FLA.