Battery system setup

Hi
From the information I have gleaned the fuel cells are not an economic proposition for constant use yet.
There appears to be a German one and a French one that run on Methanol.
They convert methanol to hydrogen to electricity and will give you three days running to produce 300AH if used continuous off 5L of methanol.

The methanol is supplied in 5L canisters and is imported and costs around $60 the last time I checked.

The only Methanol supplyer in Aus is Coogee Chemicals in Victoria and so far their product has not been approved for use in the cells.

I can get it for $1 per litre so I hope the use of it changes as it may be then worth another look.

A fuel cell is only viable to use if you have too much money or you use it as a standby for solar in inclement weather conditions to limit the running cost.

The capital cost unless reduced since I checked was around $5500 so with the continuing cost of the methanol as is who can afford it yet.

Not Me.
Ian

Many thanks for the info, thought it was too good to be true.
Will stick to the dual battery and extra waeco battery (just in case).

Any good camping area in Cape Range national park preferably on the Charles KNife Rd or Canyon pothole road?

Also we are planning to travel from Coral Bay to Yardie creek along Ningaloo,
prefer to camp southern side of Yardie Creek before crossing over any info would be appreciated? Hope to throw in a line!

cheers MIke and the navigator lolol

Ummm 'DEAD' flat is what voltage, zero or 10.4v ?

Mainey
If a battery has 10.4v in it then its not flat is it

Then at what voltage is a 12v battery concidered as "dead flat" ??

Will a 12v Cranking battery @10.4v start a 4x4... not sure, never had a 12v battery get that low, but don't think it will start a diesel engine.

I've never had a 12v battery under 12.o volt, even when actually running the fridge, the fridge auto cut-out is set @ 11.5v and has never been activated.

The open circuit voltages listed approximate the various State of Charge (SOC) of a 12 Volt AGM battery.

12.80 volts = 100% SOC
12.55 volts = 75% SOC
12.20 volts = 50% SOC
11.75 volts = 25% SOC
10.50 volts = O % SOC

Mainey
What do you do with your torch batteries when they no longer light the bulb,
I have restarted my Troopy at 8.6v as shown o the GPS Voltage, mind you it was warm and only then it just got it.
But yes we all say the battery i flat if it won't start the car,

Doug, my 'torch' batteries never go flat 'cause I keep swapping low batteries for fully charged batteries when they get 'dull'
I use Energizer "rechargable" AA & AAA batteries so I just swap them with those in the Energizer charger which is permanently connected to one of the four electrical connections on the Inverter.

Oh.....OK .. Energizers eh ,...then how Mainey of them do you use to start the car

lol

Doug

Ian, not sure that your statement below is entirely true:
'Optima along with two other American AGM's Lifeline and Oddesey were developed for the US Army and are basically the only AGM Batteries that will accept a high current recharge due to the Expensive Recombination Technology.

Most cheaper AGM batteries cannot accept the same high current recharge as they do not embrace the same technology and if they did would more than likely be as expensive'

You seem to suggest that only the three brands you mention have recombination technology.

Fullriver says they have recombination technology and quote 'over 99% gas recombination'. I can not vouch for the accuracy of their statement, but it is what is quoted. Not sure about other brands. I only took an interest in Fullriver, since that is what I use (4 of them).

But then Fullriver is no longer cheap. A 120 AH now costs close to $350. Perhaps cheaper than the brands you mention, but not a lot.

ALL Quality AGM's will accept a "high current charge" because they do use the same 'technology' as optima.

The 'maximum' charge from the Alternator / regulator will be in the vicinity of 14.4v and only for a short initial period, which is acceptable to AGM batteries, even the 'entry level' Fullriver brand.

Ian, after a very quick look at available info, I have no reason to doubt that what you say is true, though I can find only broad, not specific references to it. In any case, I am swayed by the fact that American technology on this sort of stuff is expected to be more advanced than Chinese.

From my look though, I wonder what (if any) the practical advantages are to people who use AGMs for vehicle and camping type applications.

On a Lifeline web site, when they describe the low internal resistance and high charge capabilities of their AGMs, they say that owners of high output alternators will get the advantage of this. They don't state what they regard as a high output alternator, but other sites (while not giving a definition) seem to talk about 80 Amp and above as being high output. My (and I suspect most other) 4WDs, have an alternator rated below that level. When not charging in the vehicle, most of us charge with solar or multi stage chargers via a generator (or 240 V when available). Neither generate anything close to 80 Amps in a practical situation.

I found reference to AGMs accepting charge of 75% or more of their rated AH capacity. A 120 AH AGM (pretty common), would accept 90 Amps. My 210 AH (90 + 120) in the Hilux could accept 157 Amps. Both way beyond the capacity of any standard alternator, and well beyond the capability of battery wiring most use (6B&S and 50 Amp Anderson plug). In my case I use 25mm sq cable and 175Amp Anderson plug, but that is pretty rare.

Further I have read on a number of sites, that while AGMs can accept a very high charge current, in the interest of longevity of the battery, 'normal' charging should be at no more than 25% of the battery bank AH capacity (one site quotes 30%). So in my case, maximum 'normal' charge current should be not more than about 50 Amps.

I am simply stating what I have read. Nothing from personal detailed knowledge. While my first trade was Electronics Technician (4 year Army apprenticeship), that was many years before AGM technology came into common use. I therefore claim a 'general' knowledge of this sort of stuff and the ability to broadly understand new stuff that is presented to me - but no more.

So, while I am not disputing what you have said about American AGMs and their ability to accept higher charge currents when available, I am questioning the benefit it provides to the normal user who visits this site. In a military application, for which these batteries were developed (batteries in a tank for example) it might be quite different.

Not looking for a dispute on this. Just to get an understanding of the practical application of the new information (to me) you have presented on the forum.
Norm C

Norm,
You ask-> "From my look though, I wonder what (if any) the practical advantages are to people who use AGMs for vehicle and camping type applications"

First and possibly foremost, keeping it strictly NON-technical Absorbed Glass Mat (AGM) batteries is a "technology" a different design or different format INSIDE the battery.

AGM batteries are a totally different battery to a conventional WET CELL battery because internally they are made completely differently, wet cell batteries have 14 to 17 thick plates and AGM's have a minimum of 35 PLUS thinner plates separated by a 'glass' envelope that holds the electrolyte, their technical specifications are totally different, the only similarity is most are black coloured.

AGM's will recharge MUCH faster than a conventional wet cell battery.
AGM Deep Cycle batteries can be "safely" cycled to a lower voltage and more "often" than a wet cell battery.
AGM's are made in both CRANKING batteries and also DEEP CYCLE batteries, as AGM actually refers to the Absorbed Glass Mat (AGM) 'technology' of the battery not the 'end use' of the battery.

Thanks for that Mainey, but you have missed the key point of the discussion.
I am not questioning the practical application of AGMs (after all I have 4 of them; all Fullriver). You need to go up to the previous response and follow-ups to get the full discussion.

Ian (Wheeleybin) has commented that American AGMs have much higher charge rates than other AGMs due to more advanced gas reabsorbtion technology and seems to suggest that they are therefore a much better battery.
I am commenting that even if this (higher charge rate than other AGMs) is true, it seems to offer no practical advantage to the vehicle / camping user of AGMs.
I'm saying that the average user is unable to take advantage of any higher charge rate the American AGMs might have. Our alternators can't generate enough current. Our typical 240V chargers are not big enough and our typical vehicle wiring cannot handle the charge currents suggested.

On this measure at least, we are probably better off saving our money and getting Fullriver or similar. Even if they do have lower charge rates than American AGMs (but still much higher than other non AGM batteries), it seems to me this makes them more suited to our applications, not less.

I'm just looking to clarify and get a better understanding of this issue. I'm already sold on the benefits of AGMs.

Norm C

Information from the relevant battery web sites indicate that Fullriver and the "quality" American batteries mentioned have similar charge numbers.
These charge voltages would be available from an Alternator also.

Suggested charge times for 100% discharged ODYSSEY® battery.
10A charger
PC 1200 = 4 hour
Note that the charge times recommended are based on an assumption that the ODYSSEY® battery is FULLY DISCHARGED with an open circuit voltage of 11.6 volts.

An automatic charger brings the battery up to 14.5v then switch to a float (trickle) voltage of 13.6v it will stay at that level indefinitely.

* * * * * * * *
Lifeline AGM batteries.

Charge with voltage-regulated charger the following charging voltages are recommended for maximum battery life.

2 x Stage Chargers
14.2 - 14.4 volts = Bulk charge
13.2 - 13.3 volts = Float charge

Single Stage Charger
Bulk 14.2 - 14.4 volts
Once the battery is fully charged, remove it from charger.

Hi NormC, mate you really need to look up the specs for your batteries.

Unlike flooded wet cell and Gel Cell batteries, where the charge and use stats vary only marginally from one make of battery to another, AGMs have as many completely different specs as there are as many different manufacturers and even AGM batteries made by the same manufacturer can have completely different specs.

So with AGM batteries, you MUST look up the specs for your specific AGM battery and don’t just take it that the specs for one brand of AGM will pretty well cover all AGMs.

For example and even though you have quoted a few different specs as a generalised comparison to most AGM batteries, the batteries you are using, Fullriver, the manufacturer states that all their AGM batteries have a maximum recommended charge rate of just 20% of the battery’s A/H and this is at a room temperature of 25 degrees and so if the battery is in the engine bay, the maximum charge current and charge voltage drops, while Optima state that some of there batteries can take full inrush currents while charging and at higher voltages.

If you choose the use AGMs make very VERY sure you know the exact specs for your specific battery, otherwise it could be a very expensive learning curve.

Cheers

Thanks for that Drivesafe.
As stated up further in this thread, I was aware that many AGMs are rated to be charged at 25% of AH capacity. I was not aware of the 20% provision for Fullriver and still have not been able to find it. If you can give me a link, that would be helpful.

In any case, as also stated above I run two AGMs in parallel in my vehicle, Totaling 210 AH. When I have the CT connected, AGM bank capacity goes up to 330 AH. 20% of those two totals is 42 Amps and 66 Amps. I might occasionally be able to go over the first limit by a small margin, but am incapable of continuous charging over the second limit.

This is exactly the point of my posts here. American AGMs may be of a better 'quality', but they are also much more expensive. The major discussion I have engaged in here is about high charge rates for AGMs. It is claimed that American AGMs can accept virtually unlimited charge currents. That may be so, but on this measure, why would I pay more to get this capability when I am incapable of charging much faster than my current batteries are rated to accept?

Hi again Norm, there’s a link bellow and once there just look for your specific battery.

The site lists PDFs for each battery they make so you can down load the info for your type and size of battery.

Have a look around that site as it has some excellent info, such as expected number of cycles based on the depth of discharge and so on.

Here’s the Link

Fullriver Battery Datat

Thanks for that Drivesafe. I had been to that site before, but was not smart enough to click on the battery type to get full data.

The charge current limitation (24 Amp or 20% for 120AH) is referred to as 'Initial charge current'. When using my CTek 25 Amp charger, it has an initial charge current limiter so it starts up at low current, them moves to maximum current when terminal voltages reaches a 'set level' (don't knw what that level is).

If I am reading the data right, the limit is on the initial charge current, not the full bulk charge current. The reason I raise this is that I have a 60AH Fullriver AGM that I use in my boat. I charge it with the 25 Amp CTek. At bulk charge (after initial charge cycle) the battery is receiving 25 Amps, about double the 'initial charge current' quoted in the Fullriver data. I've been doing this for over 12 months will no ill effect (that I can determine).

I'm figuring that if charging with my CTek, there is no issue. The only problem is if you have (say) a single Fullriver connected to charge from alternator. Initial charge current will be above the specified initial charge current.

Norm, the vehicle Alternator supplies the 'current' to the battery through a "regulator" which actually regulates the current going to the battery.

Using a 100 Amp alternator (for example) the full 100 Amps will never get to a charged battery because it would explode it instantly.

When a battery is or close to fully charged, as I've stated above, only a minuscule (single digit) number of Amps is going to the battery - not the full 100 Amps.

Conversally, if you have too many batteries in a battery bank connected to the power supply they may never get the complete "full" charge needed to keep them fully charged.
The secret is to not let them get 'flat' in the first place and this is a major benefit of using Solar power to recharge storage batteries, but that's another subject and not relevant to the original post.
A battery that is 'flat' is harder to fully charge than one that is only 1/2 'flat' and sulphation starts and in no time the battery will not accept charge causing it to remain 'flat' and useless.

Mainey said:
"Using a 100 Amp alternator (for example) the full 100 Amps will never get to a charged battery because it would explode it instantly.

When a battery is or close to fully charged, as I've stated above, only a minuscule (single digit) number of Amps is going to the battery - not the full 100 Amps."

Mainey that's about as useful to the discussion as 'Grandmothers make great Apple Pie'.

Just about everyone knows it is true, but it has nothing to do with the current discussion.

We are talking about MAXIMUM charge current, ie initial charge to a discharged (say 50%) battery. Not the miniscule current drawn by a fully charged battery, which of course is well below the 20% of AH capacity quoted by Fullriver.

Ian,
I think I've answered the "high amp input high cost AGM compared to the low cost low amp input AGM battery" question in the above post, the INPUT Amps to ALL AGM's (not Gel) are close enough to call them even, similar or the same.

The relevant information is copy/pasted from the battery web sites so it's not my 'opinion' but the battery manufacturers specifications placed there to avoid any confusion or debate with their specifications.

The high Amps are only relevant to the charging of a almost dead battery as when the battery is over 3/4 charged the Amps are only extremely low single digit numbers.
Hope you now accept I have an open mind on AGM batteries, I have to, i cel em :-)

wheeleybin, problem here is posting of CONFLICTING information...

"GEL" batteries
EXIDE Specs 14.4V @ 20oC absorb time 10-12 hours

"GEL" & AGM batteries
USA Specs 14.1 @ 20oC absorb time 4-10 hours

Fact is "GEL" batteries MUST be charged at a lower rate than AGM batteries, to confirm this look at any 'quality' charging device, it will have two (2) charging positions, "Wet cell & AGM" and then it will also have a "GEL" battery settings, which are at a lower rating, reason being because GEL batteries cant tolerate the high charge rate that Wet cell & AGM can.