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Forum Index : Solar : Need help with battery selection

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Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 10:52pm 18 Jun 2012
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Need some help with choice of battery.

Would love to get 12V up to 100Ah.

Some batteries are supposedly OK to draw down to 50% without damage.
Others seem to be better cycled not lower than 75% and then quickly brought back to 100%

I am looking up information on AGM batteries.
(Appears my gel type battery is AGM – just clicked on what stands behind the letters few days ago.
I like this type of battery as don't have to stress out on when to top up

I try to make informed decision, and looks I need some help.

Searching for AGM batteries few brands popped up:

Century

Deka

Geltech

Lifeline – must be good as have premium price

Remco – here they have two types: dual purpose and deep cycle, not sure which one is better?

SSB Deep Cycle – again 2 types: Cyclic and Cyclic (SHORT) not sure again which one is better?

They all are mentioned to be AGM, but some also say that they are lead acid with valve.
Supposedly sealed battery but if with valve, then in certain circumstances valve will let some vapour go and top up would not be bad idea, but no access to do it.

Is there anything else I should consider?

Would any of them last up to 20 years with good care?

Is it possible to go with cheaper battery and still make good life out of it?


George
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 4406
Posted: 01:18pm 21 Jun 2012
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They are ALL lead acid batteries, and NONE of them are completely sealed.

If you want long life, use a flooded lead acid battery, simply because you can monitor and top up the electrolyte, and you can safely fast charge it.

If you plan to use a battery inside equipment, inside your home, or for a portable application where acid spills would be a huge problem use a "sealed" type battery.

The problem with a "sealed" battery is they still have vents to prevent pressure buildup and rupture, and they will dry out if they are fast charged or charged to higher voltages where they will gas. And there is no way to replace the missing electrolyte once it has all vented.

Sealed batteries are totally unsuitable for fast charging or deep discharge, they will die pretty quickly. Only really suitable for lower current charge and discharge standby applications, maybe at a ten hour rate absolute maximum for both.

Just because "sealed" batteries are hugely expensive for their size, does not make them a superior battery.

Flooded batteries are far more robust, and can even recover from slight sulfating, with proper treatment, and will last many years if well looked after.
Sealed batteries are expensive throw away items, once they start to get sick and lose capacity they very quickly become useless.

I use both, each have their place.
Cheers,  Tony.
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 02:51pm 21 Jun 2012
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  Warpspeed said  
...

Flooded batteries are far more robust, and can even recover from slight sulfating, with proper treatment, and will last many years if well looked after.

...



Thank you very much for thumbs up for this type.

Battery will be in garage and I don't think that explosive gas would build up there, as roller doors have quite a few gaps and air moves there easily, not to mention that garage is well over 3m in height.
On top of that I can arrange forced air movement too, should I start to smell something.

As much as not having to do anything is appealing, but I'd rather do some maintenance every day if I can extend the life.

With 80W Solar Panel charging will not be rapid, and I will be able to buy much larger flooded battery for the same $

Would you be so kind to steer me toward good deep cycle flooded battery with reputation behind it?

George
 
yahoo2

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Joined: 05/04/2011
Location: Australia
Posts: 1166
Posted: 03:42pm 21 Jun 2012
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  Georgen said  
Would love to get 12V up to 100Ah.

I try to make informed decision, and looks I need some help.

Is there anything else I should consider?

Is it possible to go with cheaper battery and still make good life out of it?


Georgen, if this was a school project the teacher would possibly mark you with a big F for fail.

I know from your recent posts that you are very reluctant to spend money on panel wattage or a regulator that will precisely manage your battery's charge.

I was fine with those decision as I thought you understood that there would be consequences from this.

1/ small low watt panels mean that only a small battery can be charged.
2/ poor regulation means a short battery life, the battery loses a small amount of capacity every time it is not charged correctly.
3/ leaving a battery overnight undercharged will reduce a battery's total life by more than a week every time it is done.


I know you want to use one 80 watt panel, you need to stop looking at gadgets on the internet for a couple of days and sit down with pencil and paper and think about your possible power use and do the basic calculations.

I am willing to give you a hand here.

I think your 80 watt panel will produce a MAXIMUM of 160 watts a day in winter, 620 watts a day in summer and 370 watts a day in spring and Autumn.

Try and work out if those numbers are correct for your area and will it charge a 100 Ah battery and run your appliances.

I will be interested to see what you come up with.

regards yahoo
I'm confused, no wait... maybe I'm not...
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 12:53am 23 Jun 2012
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Weekly I would charge:
mobile phone twice
Few AA nd AAA batteries

Forthnightly:
Shaver

Monthly:
GPS
Rechargeable screw driver,
Drill

Think about security light outside garage
Would not be used that often, but don't have it yet as I look for 12V system.

If system will allow, I could also use Laptop under 30W (measured on 240V usage)

I can use only few of the items mentioned if system too small.

Fan will probably go directly on separate 5W or 10W solar panel.
George
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 12:31am 06 Jul 2012
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Wouldn’t it be easier to reverse-engineer the system?

Say for example I have :
18Ah AGM Battery and now I got 40W Solar Panel

If I halve this:
[quote]

I think your 80 watt panel will produce a MAXIMUM of 160 watts a day in winter, 620 watts a day in summer and 370 watts a day in spring and Autumn.

[/quote]

I’ll have with 40 watt panel:
80 watts a day in winter
310 watts a day in summer
180 watts a day spring, autumn

Battery loses 1% a day, there are some other loses

How much power could I use leaving battery fully charged?
Edited by Georgen 2012-07-07
George
 
brucedownunder2
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Joined: 14/09/2005
Location: Australia
Posts: 1548
Posted: 11:53am 06 Jul 2012
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Hi george,,

from the figures ,re usage..

I'd forget it ,,just get a plugpak and power the stuff from that .. You are talking a couple of cents here per week,not enough to buy a coke..

1000 watts will cost you ,say,20-23 cents from your provider.. you are thinking about using a couple hundred watts per week --work that out..

Bruce.
Bushboy
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 01:47am 19 Aug 2012
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Found this 12V battery specks and would like to ask, if it sounds good enough for experienced Deep Cycle Battery users?
(as I am not sure what actually makes a battery to be good for deep cycle application)


"BATTERY DEEP CYCLE 100AH 12V 4WD/TRUCK/MARINE,SOLAR

Features:
1. EXTRA THICK DEEP CYCLE PLATES
2. ENVELOPE GLASS MATT SEPARATOR FOR POWER
3. SOLID LEAD TERMINALS--DUAL FIT, WITH WING NUTS
4. CARRY HANDLE.
5. VIBRATION PROOF CONSTRUCTION
6. LOW MAINTENANCE
7. HEAVY CAST LEAD CONNECTIONS
8. PURE LEAD CAST PLATES-MUCH LONGER LIFE THAN NORMAL BATTERIES"

George
 
mac46

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Joined: 07/02/2008
Location: United States
Posts: 412
Posted: 01:46pm 19 Aug 2012
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Georgen,

What you just listed is a medium duty battery...a cross breed between a true deep cycle and a regular truck battery. They have lighter connecting luggs inside, and this is what I "believe", "not sure", is why they blow up more offen.
Go to a large farm supply store and purchase a pair of deep cycle 6 volt golf cart batteries...they run about $100 each. These are a true deep cycle battery, or you can go one steep futher and purchase the industrial 2 volt cells. If properly cared for they will last for many years.
Even the ones advertised as "pure lead" are not 100% pure lead.
Mac46 Bruse downunder2 has it right, you should consider what he says.
I'm just a farmer
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 11:49pm 21 Aug 2012
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I understand that I could walk away from setting up anything electrical, if I have access to town power.
What I like is that without noisy generator disturbing neighbours I could have some lights, maybe Laptop and possibly TV going should there be blackout.

Would be also nice to have fridge going, but that’s probably out of question with little system.


Could somebody tell me if 2 batteries 6V connected in series could be connected to 12V desulphator, or it is out of question.

Desulphator has shown voltages: 12V, 24V, 48V and most probably 24V and 48V are not straight batteries with this voltage, but smaller batteries connected in series.

George
 
mac46

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Joined: 07/02/2008
Location: United States
Posts: 412
Posted: 03:55am 22 Aug 2012
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Yes, they can be connected that way to the desolphinator, I have multiple pairs of 6 volt batteries connected this way, works well. The thing is that with all mutiple batteries in a grouped bank you will need to check that all the batteries are about equal in the charge state. Sometimes you will have a battery that laggs behind the others and needs individual chargeing to become the same as the others.
They do not have to be exactly the same, close would be nice.

Mac46
I'm just a farmer
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 06:38pm 22 Aug 2012
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Thank you Mac46,

This way I can have 2 off 6V 100Ah deep cycle batteries about 15kg each.

They will be quite easy to move around, compared to moving a 30+kg battery.
George
 
Barry T Coles

Senior Member

Joined: 30/07/2009
Location: Australia
Posts: 109
Posted: 10:59pm 22 Aug 2012
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  Warpspeed said  
The problem with a "sealed" battery is they still have vents to prevent pressure buildup and rupture, and they will dry out if they are fast charged or charged to higher voltages where they will gas. And there is no way to replace the missing electrolyte once it has all vented.


I have a couple of so-called sealed batteries at home in Karratha ( Currently in Perth for a couple of months so cant post pic).

When you have a close look at these batteries you will see a small cut out on the bottom edge of the cover for the wet cells; these covers are only lightly glued to the top of the batterie & can be popped off, arm yourself with 3 flat screwdrivers about the same size as the cut out and gently prise the cover upward this wil crack the glue, tthe first time it cracks you may think you have stuffed it but is generally not the case, once you have made that first break in the glued seal you cab gently work your way around the cover and do no more damage than breaking the glue away from the plastic.

Once you have this cover removed you will be able to see inside the wet cells & top them up if needed.

As you remove this cover it will get a bow in it that can easily be straightened out bylaying it upside down on a flat surface & pouring hot water over it and imediately placing a house brick or weight of some kind on it to hold it flat till it cools.

I have managed to salvage 2 170Ah batteries by doing this.

Cheers
BarryEdited by Barry T Coles 2012-08-24
I need to learn from the mistakes of others.
I dont have the time to make them all myself.
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 12:58am 23 Aug 2012
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This is exactly what I went through, with my 17Ah AGM
Started lifting up at the notch, cracked something and thought 'I think I broke it'
then I thought 'might as well keep lifting'




'Notch' Fragment taken from this picture:



George
 
Barry T Coles

Senior Member

Joined: 30/07/2009
Location: Australia
Posts: 109
Posted: 07:24pm 23 Aug 2012
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  Georgen said   This is exactly what I went through, with my 17Ah AGM
Started lifting up at the notch, cracked something and thought 'I think I broke it'
then I thought 'might as well keep lifting'


Hi George

A couple of good pic's & it looks like you have a very good battery for the effort.

  Georgen said   then I thought 'might as well keep lifting'


And why not if in the end you are only going to take the battery to the scrap merchant you may as well have a look inside anyway to see how it ticks.

I shudder to think how many good batteries are thrown away simply because of this.

Cheers
Barry
I need to learn from the mistakes of others.
I dont have the time to make them all myself.
 
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