Got this out of a training manual and thought it may fit into the Techo forum when it get up and running. In the meantime those thinking on battery replacement may wish to consider AGM as the most suitable alternative to lead acid or Gel cells,
Don't fall for buying big, sometimes two smaller units connected in parallel can work out cheaper than one big fella and also fit into a smaller space and easier to load into a tight space .
Also included a bit on battery maintenance that may be helpful .
AGM Batteries
Absorbent glass mat (AGM) is a class of lead-acid battery in which the electrolyte is absorbed into a fiberglass mat. The plates in an AGM battery may be flat like wet cell lead-acid battery, or they may be wound in a tight spiral. The internal resistance of AGM batteries is lower than traditional cells, they can handle higher temperatures, and self discharge more slowly.
These batteries have a valve which will activate when the battery is recharged at high voltage. Valve activation allows some of the active material to escape thus decreasing the overall capacity of the battery. The lids /vents typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be produced during charging. They are maintenance free; and they can often be oriented in any manner, unlike normal lead-acid batteries which must be kept upright to avoid acid spills and to ensure the plates are sitting in the electrolyte.
AGM batteries are totally sealed and are easy and safe to transport
They NEVER topping up with water
They can be safely mounted inside a boat, car, caravan
AGM batteries only need to be vented to atmosphere, they do not need to be in a sealed box vented to the outside like wet batteries, and can be mounted on their sides or ends if needed.
Due to their very low internal resistance AGM batteries will fully charge at a lower voltage, and accept a much larger charge current, so when charging from a standard car/truck alternator these batteries will all but fully charge, and they will charge quickly, in about 3 hours!
AGM batteries can be discharged deeper than conventional deep cycle batteries without major damage.
AGM batteries only self discharge at the rate of up to 3% per month, and even after 12 months sitting idle can be recharged and put back into full service without any major damage. (A standard deep cycle battery if treated the same way will have destroyed itself, it will no longer hold a good charge)
AGM batteries were originally developed for the military, they are very robust.
Battery Maintenance
Deep cycle batteries such as those used in solar power systems have much thicker lead plates to make them last longer. Deep cycle batteries should never really be discharged to below 20% of their full capacity, because internal resistance causes heat and damage when they are recharged. Renewable energy systems usually use a low-charge or low voltage warning light or a low-voltage cut-off switch to prevent the type of damage that will shorten the battery's life.
Battery shelf life can be extended by storing them at a lower temperatures, because the chemical reactions in the batteries are slower. However, in order to reach their maximum voltage, batteries must be returned to room temperature. Therefore, most battery manufacturers do not recommend refrigerating batteries.
Battery safety, explosions and other hazards
A battery explosion is caused by the misuse or malfunction of a battery, such as attempting to recharge a non-rechargeable battery or short circuiting a battery. Explosions are most likely to occur when a short circuit generates very large currents. In addition, deep cycle batteries can release hydrogen when they are overcharged (due to electrolysis of the water in the electrolyte). Normally the gas dissipates quickly. However, this gas can be ignited by a nearby spark (for example, when removing the jumper cables).
Attempting to charge a battery beyond its electrical capacity, ie overcharging, can also lead to a battery explosion, leakage, or irreversible damage to the battery. It may also cause damage to the components in which the overcharged battery is used.
When a battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting. In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury.
Battery explosions can also occur in maintenance free lead-acid batteries if the valves fail or are blocked. The pressure rises within the cells until a short-circuit ignites the hydrogen-oxygen mixture. Such explosions can cause severe injury. The problem can be detected in most batteries if the sides appear swollen, or if the battery feels hot to touch.
-- Edited by Wombat 280 at 09:39, 2009-02-15
ibbo said
07:02 PM Feb 14, 2009
Gee Wombat,you have left me shell shocked.But thanks for the info.I guess that I will have to get rid of my crystal set(who remembers the cats whisker").Just a bit of humour mate.Cheers.Ibbo.
dave06 said
07:08 PM Feb 14, 2009
hell the crystal set, there was a bit of magic from my youth, straining to hear the little squeeky voice, very good post for the young players there wombat, I've really got to be carefull around your posts or I'm likely to learn something and we cant have that now can we
perhaps a little warning at the beginning of your posts something like "caution the following information may contain information that if used incorrectly may increase one's general knowledge base, continue reading at your own discression"
mike and Judy said
08:01 AM Feb 15, 2009
hahahahahha dave, you are displaying your age young fella,
you probably know how to use an axe, (in the days before chain saws) will need a licence for them one day, and the milk and cream as seperate entites delivered to your door,
,
dave06 said
09:41 AM Feb 15, 2009
funny you should mention the Axe, we stayed a night at the cradle mountain rip off centre, er!! I mean the cradle mountain campsite for a night and we went for a wander as you do, had a look at the campers kitchen/lounge/dining room, huge place, fantastic setup, two great fireplaces and two sets of cooking areas as well as free bbq's by the dozen, anyway just off to the side of the huge fireplaces was a room with "please shut the door so as not to trap small animals"
of course this intrigued me, had to have a look see, anyway had a nose and it turned out to be a separate woodshed, on the wall was a huge set of instructions on the use of the Axe, not to be used in anger, don't kill people with it, no kiddies to be chopped up, clean up your blood and body parts, that sort of thing, I looked around to see what sort of Axe it was and there it was......... gone!!!!!!! with another big note on the other side wall emblazoned in texta........axe removed for safety reasons.......well I just shook my head and walked away
psssttt!!! don't tell anyone, but I used to turn the butterchurn to make the butter, and also spun the milk separator so yes I do know what REAL cream tastes like fresh from the cow, and we moulded our own butter, none of this shop bought taste free rubbish
Basil Faulty said
01:56 PM Feb 15, 2009
ibbo wrote:
Gee Wombat,you have left me shell shocked.But thanks for the info.I guess that I will have to get rid of my crystal set(who remembers the cats whisker").Just a bit of humour mate.Cheers.Ibbo.
You only used a crystal set to avoid paying for a "radio listeners licence"... I know your type!
Basil Faulty said
02:00 PM Feb 15, 2009
mike and Judy wrote:
and the milk and cream as seperate entites delivered to your door,
Oh yes indeedy.... It came in the back of a horse drawn cart and was measured into a "Billy"..... But who can remember using a separator? and cleaning the cones when it was done... Nothing like fair dinkum milk from a cow, full cream just chilled..... I must be gotting old, next thing someone will sick ACAT onto me...
Basil Faulty said
02:04 PM Feb 15, 2009
Thats true about 2 smaller batteries in parrallel. usually one cell dies and you have to replace the whole shebang... Ive seen these AGM batteries in single 2 volt cells somewhere with various amp/hour ratings, the idea was that you could build your own battery. I'll go look for the link, I think it was @ Battery World....
mike and Judy said
05:30 PM Feb 15, 2009
We had our milk delivered by Athol from across the road, running Jersey cows, used to help occassionally, mum and dad had a brindle dane and one pitch black night I met him in the drive, the dog growled and he near got to the top of an old pine tree in 2 secs flat, milk all over the dirt, couldnt stop laughing for a week, still have a chuckle when I see Great Danes, really amaible dogs
JRH said
05:46 PM Feb 15, 2009
Basil Faulty wrote:
ibbo wrote:
Gee Wombat,you have left me shell shocked.But thanks for the info.I guess that I will have to get rid of my crystal set(who remembers the cats whisker").Just a bit of humour mate.Cheers.Ibbo.
You only used a crystal set to avoid paying for a "radio listeners licence"... I know your type!
Ah!! The crystal set, I remember building them when I was a kid, around 1952 that would be. Didn't need a Radio Licence in Rhodesia (Zimbabwe)
John
ibbo said
09:38 PM Feb 15, 2009
Back to the crystal set.........apart from the cats whisker,what about the earphones?.I am sure that mine came from a Shackleton Bomber Plane.I remember one radio show."Dick Barton,special agent".You can always tell when Happy Hour has passed,you always remember something from the past..Cheers Ibbo.
mike and Judy said
07:28 AM Feb 16, 2009
Hey Ibbo , I am an old fart and I remember that "Dick Barton form when I was a kid in England, all four of us were grouped around the wireless, holding our breath
Wombat 280 said
03:17 PM Feb 16, 2009
Overlooked mentioning one of the drawbacks of battery connections in parallel.
They seem to charge and discharge unevenly which can effect battery life expectancy . There are other drawbacks which are more on the techo side which could effect a parallel setup so unless you are in the electrical game or fully understand storage batteries and battery charging systems , don't bother.
The use of smaller units in a individual connection can save you dollars and is something worth a second look at if you are in the market for batteries even if you need to put in an isolator between two to switch between units as required .
Sorry if it all sounds confusing , it's not an easy topic to discuss outside the trade but we all seem to need or have come to rely on storage batteries in our travels so it may help to gain an understanding so you don't get a lemon
-- Edited by Wombat 280 at 14:22, 2009-02-16
Basil Faulty said
04:53 PM Feb 16, 2009
mike and Judy wrote:
We had our milk delivered by Athol from across the road, running Jersey cows, used to help occassionally, mum and dad had a brindle dane and one pitch black night I met him in the drive, the dog growled and he near got to the top of an old pine tree in 2 secs flat, milk all over the dirt, couldnt stop laughing for a week, still have a chuckle when I see Great Danes, really amaible dogs
Yes Danes are true gentle giants, but many people are intimidated by their sheer size. There is one named "Outzen" in the agility club and he is amazing.... Except in the tunnel, he has to crawl LOL
ibbo said
08:27 AM Feb 17, 2009
Dick Barton,special agent.Dick,Snowy and Jock.Hey not even happy hour and I rembered that.Be Mrs Dales Diary next.Cheers Ibbo.
dave06 said
10:21 AM Feb 17, 2009
I remember as a young feller visiting rellies in the city, there was a very distinct anomally occuring that I had never seen before
there was this little fellow all dressed in white who would leave milk and or cream and sometimes orange juice in bottles contained in little wire baskets with a handle at peoples front door
whats more he was followed all over the place by a horsey pulling a wagon filled with these things, that horsey knew every street that milky had to go and when to shift up, at no point was the horsey given instruction or growled at
in fact the milky would quite often cease his tireless running to and fro between houses to give his horsey a pat and a drink, times have changed, the same horse would now be belted if it so much as farted
the days of magic have truly left by the side door, however we have new and different toys now, but as we gain more and more new toys they fail to capture our imagination like straining to hear the drama unfolding on a wireless that can barely support itself neverlone gaining a signal
wombat I am sorry to say that I am one that stands accused of hi-jacking your thread, and I apoligise for it, what you say makes a lot of sense in all aspects, I have worked on a lot of upmarket systems that come to me from time to time and can state categorically that the day of the single or double lead acid battery as a large supplier of power in motorhomes is almost gone
however for simplicity (always my banner to which I hold proud) and price I still see and use myself a lot of single large lead acid batterys as a main low draw power source for those that dont want to take the city with them
the prohibitive cost of multi battery systems and then the prohibitive recharging aspect puts them out of the reach of all but the most spoilt, me included, when I go, I leave all the garbage behind, (see photo of brady's lake), magical, no need for t.v. or microwave or wireless, just the occasional light, a cool beverage and the company of good freinds does me just fine thank you
but a good post nonetheless, keep it up, you are a highly valued contributer!!!!!!
Mike47 said
08:01 PM Feb 17, 2009
mike and Judy wrote:
Hey Ibbo , I am an old fart and I remember that "Dick Barton form when I was a kid in England, all four of us were grouped around the wireless, holding our breath
Yeah, but can you remember "Who knows what evil lurks in the hearts of men . . . Heh, Heh, Heh, The Shadow Knows"
Got this out of a training manual and thought it may fit into the Techo forum when it get up and running. In the meantime those thinking on battery replacement may wish to consider AGM as the most suitable alternative to lead acid or Gel cells,
Don't fall for buying big, sometimes two smaller units connected in parallel can work out cheaper than one big fella and also fit into a smaller space and easier to load into a tight space .
Also included a bit on battery maintenance that may be helpful .
AGM Batteries
Absorbent glass mat (AGM) is a class of lead-acid battery in which the electrolyte is absorbed into a fiberglass mat. The plates in an AGM battery may be flat like wet cell lead-acid battery, or they may be wound in a tight spiral. The internal resistance of AGM batteries is lower than traditional cells, they can handle higher temperatures, and self discharge more slowly.
These batteries have a valve which will activate when the battery is recharged at high voltage. Valve activation allows some of the active material to escape thus decreasing the overall capacity of the battery. The lids /vents typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be produced during charging. They are maintenance free; and they can often be oriented in any manner, unlike normal lead-acid batteries which must be kept upright to avoid acid spills and to ensure the plates are sitting in the electrolyte.
AGM batteries are totally sealed and are easy and safe to transport
Battery Maintenance
Deep cycle batteries such as those used in solar power systems have much thicker lead plates to make them last longer. Deep cycle batteries should never really be discharged to below 20% of their full capacity, because internal resistance causes heat and damage when they are recharged. Renewable energy systems usually use a low-charge or low voltage warning light or a low-voltage cut-off switch to prevent the type of damage that will shorten the battery's life.
Battery shelf life can be extended by storing them at a lower temperatures, because the chemical reactions in the batteries are slower. However, in order to reach their maximum voltage, batteries must be returned to room temperature. Therefore, most battery manufacturers do not recommend refrigerating batteries.
Battery safety, explosions and other hazards
A battery explosion is caused by the misuse or malfunction of a battery, such as attempting to recharge a non-rechargeable battery or short circuiting a battery. Explosions are most likely to occur when a short circuit generates very large currents. In addition, deep cycle batteries can release hydrogen when they are overcharged (due to electrolysis of the water in the electrolyte). Normally the gas dissipates quickly. However, this gas can be ignited by a nearby spark (for example, when removing the jumper cables).
Attempting to charge a battery beyond its electrical capacity, ie overcharging, can also lead to a battery explosion, leakage, or irreversible damage to the battery. It may also cause damage to the components in which the overcharged battery is used.
When a battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting. In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury.
Battery explosions can also occur in maintenance free lead-acid batteries if the valves fail or are blocked. The pressure rises within the cells until a short-circuit ignites the hydrogen-oxygen mixture. Such explosions can cause severe injury. The problem can be detected in most batteries if the sides appear swollen, or if the battery feels hot to touch.
-- Edited by Wombat 280 at 09:39, 2009-02-15
You only used a crystal set to avoid paying for a "radio listeners licence"... I know your type!
But who can remember using a separator? and cleaning the cones when it was done...
Nothing like fair dinkum milk from a cow, full cream just chilled.....
I must be gotting old, next thing someone will sick ACAT onto me...
Ah!! The crystal set, I remember building them when I was a kid, around 1952 that would be. Didn't need a Radio Licence in Rhodesia (Zimbabwe)
John
They seem to charge and discharge unevenly which can effect battery life expectancy . There are other drawbacks which are more on the techo side which could effect a parallel setup so unless you are in the electrical game or fully understand storage batteries and battery charging systems , don't bother.
The use of smaller units in a individual connection can save you dollars and is something worth a second look at if you are in the market for batteries even if you need to put in an isolator between two to switch between units as required .
Sorry if it all sounds confusing , it's not an easy topic to discuss outside the trade but we all seem to need or have come to rely on storage batteries in our travels so it may help to gain an understanding so you don't get a lemon
-- Edited by Wombat 280 at 14:22, 2009-02-16