What is the difference between 4x 200Ah or 8x 100Ah AGM

New to renewable energy? Have questions? Here's a great place to ask them and view information about wind and solar power basics.

What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Little Ray » Thu Jan 12, 2017 6:12 pm

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
Little Ray
Solar Supporter
Solar Supporter
 
Posts: 14
Joined: Tue Jan 10, 2017 5:47 pm

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Gordon-Loomberah » Thu Jan 12, 2017 9:13 pm

More batteries = more expense for cables, lugs etc, and more cells = more chance of one failing. It is usually best to aim for the minimum number of cells to make up your desired voltage and capacity.
A battery made up of 6 cells that you can't access or replace is not as good as having individual cells or batteries with only 1 - 3 cells, in the case of one cell failing.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Little Ray » Thu Jan 12, 2017 10:11 pm

[Moderator- removed unnecessary quoting, no need to repeat, as it is just up there^^^!]

Thanks for your thoughts Gordon,

How would you translate this into real world situation for 48v 200Ah.
The material saving and simplicity is the basis of design.
My thoughts were 12v 200Ah, although it might be possible to go a bit smaller, it is a good starting point!

When you say a battery made of 6 cells that you can't access or individual cells, I sense you are thinking of particular example of the two.

If we look at cost the 2v cells seem to be far more expensive and or require more wiring and complexity.
Are you eluding to accessible interconnected 2v cells in a 12v case, or just the option of individual 2v cells?

Interested to hear what you would choose on a limited budget, $400+ 12v 200Ah batteries are going to stretch the budget.

I am yet to study the Battery market and found a link to a 12v 200Ah Battery, only for an example!
http://lanplus.com.au/index.php?route=product/product&path=59_60&product_id=69

Cheers,
Ray
Last edited by Gordon-Loomberah on Fri Jan 13, 2017 12:41 pm, edited 1 time in total.
Reason: removed unnecessary quoting
Little Ray
Solar Supporter
Solar Supporter
 
Posts: 14
Joined: Tue Jan 10, 2017 5:47 pm

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Gordon-Loomberah » Fri Jan 13, 2017 1:00 pm

I'm thinking of both options you mention with regard to the 6 inaccessible cells. Sealed 12V batteries are not really the best option for off-grid- if one cell dies you need to buy a new 12V battery, rather than just a 2V cell.
Yes 2V cells are more expensive, but you need to look at specifications to see what you are actually paying for.

The batteries you link to are not designed for an off-grid power system, despite that being mentioned in the blurb. They are designed for standby or backup power. If you cycled to 30% DOD each night (~2.8kWh discharge, or less for higher discharge rates), you would be lucky to get 3 years of use from them according to the specifications. If you just want them as standby or backup power, mostly left on float, then they might last 10 years.

I haven't looked at prices for suitable off-grid system Lead-acid batteries in years, so can't really suggest a particular brand to suit a budget. I've had a long life from Federal 6V batteries in the past, and not so long from Trojan 6V batteries, and both were flooded cells and reasonably priced, although I did get them for trade price at the time.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Little Ray » Fri Jan 13, 2017 11:24 pm

Got a bit of a bum steer looking at AGM after I was told by a supplier it was what I needed!
Could have saved a lot of time, but the knowledge is otherwise positive.

Now it would seem FTA are the best choice for this Fixed Off-grid system.
I am aware of the evolving technology but FTA seems to be the best DIY option now?

I started looking at 6v Trojan FTA, the prices seem high for a Battery said to be cheaper then AGM.
Will check out Federal.

Much appreciated,

Ray
Little Ray
Solar Supporter
Solar Supporter
 
Posts: 14
Joined: Tue Jan 10, 2017 5:47 pm

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Gordon-Loomberah » Sat Jan 14, 2017 10:55 am

Little Ray wrote:I am aware of the evolving technology but FTA seems to be the best DIY option now?


FTA?

LiFePO4 is the best option for a DIY off-grid system now. I've been using them for over 4 years, and despite one cell's performance dropping off (replaced by another brand cell), they far out-perform any Lead-acid battery.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Little Ray » Sat Jan 14, 2017 6:14 pm

[Moderator- it's just up there ^^^^^^^^^^^^^^, no need to requote!]




Sorry, just a typo that got re-pasted.
Should be FLA or Flooded Lead Acid.

What LiFePO4 batteries are you using, and do you know of effective bank or combination for 48v 100 or 200Ah?
The google responses do not help much if you have never used a product, can you offer a suggestion to kick off?

Thanks,
Ray
Last edited by Gordon-Loomberah on Sat Jan 14, 2017 6:41 pm, edited 1 time in total.
Reason: removed unnecessary quoting
Little Ray
Solar Supporter
Solar Supporter
 
Posts: 14
Joined: Tue Jan 10, 2017 5:47 pm

Re: What is the difference between 4x 200Ah or 8x 100Ah AGM

Postby Gordon-Loomberah » Sat Jan 14, 2017 6:44 pm

I've got CALB 400AH cells, and one Winston 400AH. EV Power and EV works in WA, or Trev from Thebackshed all should be able to supply 100 or 200AH cells.
http://gunagulla.com Loomberah weather and astronomy including live solar radiation intensity and UV + Gunagulla aquaponics, organic eggs and cherries
User avatar
Gordon-Loomberah
Community Moderator
 
Posts: 5327
Joined: Thu Sep 24, 2009 10:41 pm
Location: Loomberah NSW Australia


Return to Q&A - wind and solar power basics

Who is online

Users browsing this forum: Google [Bot], MSNbot Media and 2 guests

new solar power specials