Deep cycle batteries

120AH AGM batteries by Fullriver are around $260 from memory, couldn't get much better than that, bearing in mind the weight of around 35KG. There are also some Remco 100AH AGM batteries for around the same price.

Beau ,
I was sent this info from a good mechanic in WA .



AGM (Absorbed Glass Matt) batteries have huge advantages over conventional deep cycle batteries in most circumstances, but which one will best suit your needs?

Hopefully with all the reading and research you have done you will have come to an understanding that deep cycle batteries are the way to go when it comes to auxiliary batteries, but for some people AGM (Absorbed Glass Matt) batteries will have a huge advantage over the conventional wet cell deep cycle battery.

Although this will get a little long winded, it’s well worth understanding the virtues of both types of batteries, and how you can put them to best use, I won’t go deeply into the technical details of these batteries, just point out some of their advantages, and why.

Basically it starts with how you intend to recharge your batteries, I am talking about your main recharging source here.

If you are going to be using any of the smart charging solutions, like solar panels and a quality smart regulator, or a smart 3 stage mains (240v) battery charger, or the Christie Honda petrol charger (set to hi charge), then in most cases the conventional wet cell deep cycle battery will serve you well.

If treated correctly (and few are) conventional deep cycle batteries can outlast AGM’s, but only if they are well maintained and cycled within their design perimeters, with both correct discharging/charging and equalising (now that a whole other story) and with keeping electrolyte (water) levels up.

However if your main source of charging is from your vehicles alternator, or you need to place the batteries in places that are less than optimum for safe battery storage, keeping in mind that wet cell batteries give of hydrogen (explosive) gas as they are charging, then you should consider using AGM batteries as they are totally sealed and spill proof.

Did you know that if our good quality wet deep cycle batteries have been discharged fairly deeply, it can take 8-12 hours of continuous engine running to achieve just 70-80% charge?

A bit about Alternators.

Standard car and truck alternators are designed, for various good reasons to recharge car batteries to only 70-80%, and this works very well for normal cars and trucks, but when it comes to charging our storage batteries, where of course we need as full a charge as possible, that same 70-80% is not very helpful at all.

Really, standard alternators are designed primarily to top up quickly the surprisingly small amount of energy that is removed from the battery by the starter-motor on engine start up, and then to keep up with all your accessories, radios, head lights etc, they were never designed to recharge deeply discharged batteries, and they fall short in this area unless modified or replaced with a specialised charging alternator, and smart multi stage regulator.

Automotive battery chargers suffer from much the same less than perfect regulation as car alternators, and achieve much the same results, and take a much much longer time to do it.

As an example lets imagine you have a 100 A/H(Amp Hour) battery, and you main charging source is you vehicles alternator or a standard automotive battery charger, now both of these will only charge this battery to about 75% (75 A/H), and you should not discharge your batteries below 50% (50 A/H in this case) of their capacity (see note below) if you want them to last, so all you can really safely use of this 100 A/H battery is 25 A/H, not much eh?



Note. Have you heard that you can drain deep cycle batteries all the way down, and then recharge them?

Have you been told that this is what deep cycle batteries are all about?

I hear this almost everyday that people have been told this, and by some battery sales people that should know better.

This line of thinking is totally wrong.

All conventional deep cycle battery manufactures say that their batteries are designed to be cycled to 50% of their rated capacity!

So each and every time you take these batteries below this 50% you are shortening their lives, and if you do it regularly and deeply you will even more dramatically reduce their lives.



Ok OK !! I can hear the cry's from here "but I get many more amp hours out of my deep cycle battery than what you say I can!".

The truth is that most people discharge their batteries far too low, way down until their fridges cut out, or their lights start to dim (does this remind you of anyone ??), at this point they have discharged their batteries so low that they are doing serious damage to their batteries, and consequently won't get anywhere near the life out of their batteries that they could and should normally expect if the batteries were cycled within their design perimeters.

Now remember the 100 A/H battery with only 25 A/H useable? A huge gain can be had if you are using any of the smart charging solutions, like solar panels and a quality smart regulator, or a smart 3 stage mains (240v) battery charger, or the Christie Honda petrol charger (set to hi charge), you can expect close to 100% (100 A/H) charge,

So 100 A/H capacity, discharge to 50% (50 A/H), that’s now 50 A/H useable, twice what you had before!

Now lets look at some of the direct advantages of these AGM batteries.

these batteries are totally sealed, ‘transport’ classed as spill proof, never needing topping up with water, ever!

because of this they can be mounted inside a car, caravan, motorhome etc and 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.

because of their very low internal resistance these 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 fast too, in about 2.5 to 3 hours!

they can be discharged much much deeper than conventional deep cycles without major damage.

these batteries when left unattended 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 ill effects. On the other hand a standard deep cycle battery if treated the same way will have destroyed it's self, it will no longer hold a good charge, and is sadly ready for the rubbish tip and recycling, not cycling!

AGM batteries were originally developed for the military, they are very robust and will take a real pounding.

The original AGM batteries were made in the US, brands like Odyssey, Concord, Lifeline, all excellent batteries, used extensively also in the aircraft and in the motor racing fields, but hugely expensive, there are now a lot of these (AGM) types of batteries coming out of China, and some are just rubbish.

My battery supplier (ALCO Battery Sales Australia) has found a couple of company's over in China that has been in production for many years, and have been selling batteries into the European market for a long time and have built up very good reputations, ALCO now import these batteries into Australia and are selling them through their own outlets and dealers like myself.

These AGM valve regulated batteries (also called SLA or Sealed Lead Acid) offer very good value, and when compared to standard deep cycle batteries in a dollar per useable amp hour format, they come out miles ahead, plus all the added advantages that I have already outlined, but there is still more.



Lets look at it in dollars and cents.

Using a 100 A/H deep cycle Trojan (the best), my price $295.
Useable capacity if charged with smart charging system............................ say 50 A/H, cost $5.90 per A/H

Useable capacity if charged from the alternator or auto charger only........say 25 A/H, cost $11.80 per A/H

Using a 120 A/H AGM Battery, my price $395.

Useable capacity if charged with anything.............................................. lets say 100 A/H, cost $3.95 Per A/H


Now lets look at the space saving

Lets say you needed 100 A/H useable capacity from your batteries, and your main charging system was from the vehicles alternator.

Now with conventional deep cycle batteries because you would only have 25% of your battery bank useable you would need 400 A/H of battery bank, now there are a few ways you could do this, but the least expensive way would be four x 225A/H 6 volt Trojan batteries at a cost of $1,000.

Now with AGM batteries you could have just two x 90 A/H giving you 180 A/H total, so there is your 100 A/H with plenty in reserve, and only 2 batteries at a cost of $680 all up.

So with space and money saved, and with the many other advantages of AGM batteries, they really are a very good option for most people.
Personally I will never muck about with messy, cantankerous, wet cell batteries ever again for my own needs.

I have Fullriver and ALCO branded AGM batteries in various sizes.

12V 7.5A/H 151mm Long 65mm Wide 95mm High @ 2.73Kg and priced at $35.00.

12V 12A/H 151mm Long 99mm Wide 95mm High @ 4.20Kg and priced at $55.00.

12V 20A/H 181mm Long 77mm Wide 167mm High @ 6.44Kg and priced at $95.00.

12V 33A/H 196mm Long 131mm Wide 155mm High @ 11.00Kg and priced at $145.00.

12V 45A/H 198mm Long 166mm Wide 174mm High @ 15.00Kg and priced at $200.00.

12V 60A/H 229mm Long 138mm Wide 212mm High @ 18.30Kg and priced at $260.00.

12V 80A/H 260mm Long 170mm Wide 215mm High @ 28.50Kg and priced at $320.00.

12V 90A/H 307mm Long 169mm Wide 215mm High @ 30.60Kg and priced at $340.00.

12V 120A/H 331mm Long 175mm Wide 220mm High @ 35.00Kg and priced at $395.00.

12V 200A/H 530mm Long 209mm Wide 220mm High @ 65.50Kg and priced at $695.00.

12V 260A/H 521mm Long 269mm Wide 225mm High @ 89.00Kg and priced at $890.00.

Note...sizes listed are approximate, please check with us for exact sizes

I have a deal with my battery supplier who has outlets in Brisbane, Sydney and Melbourne and a few other places in between, so I can ship these batteries from any of these outlets, and offer these batteries to you for much less than you would have to pay for them over the counter, works for me ;-)

Please email me if you need help sizing up your battery requirements

Please note, my comments in this article are for batteries that are to be used in recreational vehicles etc, and are used for the odd weekend away and a few weeks a year, AGM's used in this way have a design life of 5 to 8 years.
However if you need a battery bank that will be in constant daily discharge cycle use all year round, then your battery bank should be sized so that your daily depth of discharge is about 20 to 25%, this applies to all types of deep cycle batteries if you want them to last for many years

Val Rigoli
Fridge & Solar

Internet orders welcome
we freight all our products Australia wide
If you would like to place an order please go to our >>ORDER page<<


I can only hope it is all correct - I have no knowledge on the batteries .

Cheers ,

Willie

thank you for your very thorough and informative responses ill be using a smart charger to recharge battery ... but have to find where to get it from first $260 is good price for 120 ah fullriver if you could tell me where to buy it from....i have seen agm from bfc for $289 100 ah was thinking of buying but would like to try fullriver if someone can tell me where to get one at that price
thanks beau

I just bought a 130ah US series US Battery from Battery World.

The guy told me they are the ducks guts in Deep Cycle batteries, they better be at $360.

I will use this solely for a 68 lt Eva Kool Fridge and charge it with my gen-set and charger, He all so told me my 100 series could charge my 55 ah generic brand deep cycle set up in series with my normal battery.

The 55 ah is for my old Engel I will use as a freezer.

Cheers Steve.