AGM vs Flooded

[MickinOz]

Things are coming together, I hope to have some progress worth photographing soon.
My intentions for the electrics are simple.

Solar panel, Maximum Power Point Tracking regulator, deep cycle battery, fuse block.
3 lights in cabin, 1 or 2 in the galley depending what I can find.
power outlet in cabin, another in the galley.

I built the frame in the roof for the super duper vent with fan, but what is going there for now is one dome light.

So three circuits at the moment. Reading lights and power/usb outlet above the pillows, Dome light in middle of the ceiling, lights and fridge power outlet in kitchen.
Maybe a fourth circuit if we get serious about fitting a TV and a 5th if I find porch lights I like.
I was keen to fit an air conditioner, but the missus pointed out that if it was hot enough that we needed an air conditioner to sleep at nights, she was staying home with the house air conditioner, the shower and the toilet!
Looks like "three seasons camping" in Oz is going to be Autumn, Winter, Spring.

No shore power/AC circuits.

The Engel is supposed to draw less than 4 amps. Closer to 3 probably. They are considered extremely efficient, and well insulated.
The three cabin lights are currently fitted with incandescent bulbs and I like the idea of sticking with that. I don't mind LED, but I still find the light somewhat "unnatural" somehow.
So, I'm sorta prepared to sacrifice a couple of amps. If I can get away with it.
So call the fridge 50 watts, and perhaps 60 watts of lights.
110 watts at 13 volts = 8.5 amps or so if everything is running.

The solar panel is 250 watts - it is only just going to fit on the flat section of the roof.
It's got an MPP voltage in the low 30V range at MPP amps of 8 amps.
With a MPPT regulator at say 75% efficiency, I hope to be able to push in 12 amps or so in full sun.

So, I reckon the solar panel will be capable of replacing anything we use over night.

Which brings me to my latest conundrum.
Battery.
Depth of discharge is the concern.
A panel able to replace the power used is one thing.
Discharging your battery too far is another thing entirely.

I'm not fond of lithium just yet.
(Warren Buffet says he only buys businesses he understands. I'm the same with technology.)
I can buy a 105 amp hour flooded lead acid battery for $200.
I figured it would be big enough to ensure DOD was less than 50%, given I don't stay up that late, and generally don't have everything running all the time.

Or, the local Aldi store has 80 amp hour AGM batteries for the same price. Label says Made in Australia.
Tempted to replace all the bulbs with 3w LEDS, currently 15w incandescents, and reduce the draw considerably.
The reason I'm tempted - VRLA AGM means unlikely to spill electrolyte, no top up of the electrolyte, etc.
Who has had good/bad experiences with AGM?

[John61CT]

Yes in your market you need to spend a lot more per Ah for quality true deep cycling batteries.

Apparently no FLA brands still made there are that, you'd need to find out from knowledgeable solar or yacht sparkie types what else is as good as say Trojan or even Rolls/Surrette.

Keep your eyes open for NA brands Deka/East Penn, U.S. Battery, Crown, Superior, all are excellent but likely not available there at reasonable pricing.

All things equal, FLA does last longer and is easier to care for just more robust than AGM, but the marketing hype of the 90's made them now harder to find down under.

The NA brands for quality AGM are Northstar, Enersys/Odyssey and Concorde/Lifeline but again likely overpriced if even available at all.

Chinese imported Full River are pretty good, likely the best value, so if you really need sealed again ask around what's better longevity than them.

Finally GEL, look for Sonnenschein from Germany, or maybe Deka.

Lots of aussies swear some scam-marketed Chinese "carbon something" chemistry is miraculous, I think just AGM but who knows, only marketed to low-information types there and South Africa.

Note that excellent quality LFP is much more reasonably priced relative to lead than in the US.

T1 Terry from Mannum S.A. is worth checking out, highly recommended his banks might last 15-20 years but **listen** to his care instructions not the industry mainstream specs.

[MickinOz]

Yeah, our last manufacturer was exide. They still sell into the market, but the batteries are now made in the US or the Philippines.
Freight rates from the states being what they are, I reckon we'd be getting the Filipino ones.
The FLA I'm looking at is the same brand as the starting batteries in my truck and my boat.
The boat sits o n a solar float charger year after year and the batteries last yonks, so I'm OK with the brand I can get.
$200 is $120 US at the moment. Not too bad.

But,
a) I have to go get it (130 miles each way)
b) it's flooded - potential for leaks and hydrogen
c) DOD should be limited to less than 50%
d) it's heavy.

By comparison the AGM is
a) Local
b) sealed (sort of)
c) DOD max 80% (so they say) so effectively just as much usable capacity
d) lighter than the 105 AH

But..............ya here those little grizzles about early failure, etc.
I'm thinking a programmable regulator should be tunable to stop most of that.

Decisions, decisions.
You sure the bloke you refer to is at Mannum?
There's a bloke at Murray Bridge who really seems to know his sh**. Could be him?

[MickinOz]

P.S. Flooded lead acid is still the norm down here, by a very long shot.
Lithium is around - lots of motorcycle batteries, but 4 times the price to save two kilos for my bike, so no thanks.
AGM around, but so far the biggest I've personally laid eyes on is the 80 AH I saw today. Not a lot of AGM starting batteries.

[John61CT]

You need to understand, that the design and construction of a battery intended for deep cycling storage is fundamentally different from starter batts.

Do not bother thinking you should adapt the latter for the former application, really throwing your money away.

400Ah to 800 or even 1200Ah banks are common for people living off grid, you need to tap into the expertise and distribution channels serving that niche, especially the marine market.

First define the top companies (forget Exide) find out what model units are recommended by non-biased experts there, especially FLA in 2V or 3-6V avoid 12V batteries to start.

Post in the marine and Oz caravanners forums for help.

[John61CT]

That DoD is bulldust, do not go below 50% except rarely like in emergencies.

If you want AGM figure twice the price per Ah per year.

Heavy is good, indicator of quality for lead, AGM should **not** be lighter for the same Ah.

AGM will need much more precise infrastructure or get murdered early.

And yes T1 Terry was out of Mannum. But boat yard sparkies can put you on to others.

[KennethW]

One thing that has not been mentioned is Lithiums low resistance. Make charging and discharging a lot more efficient. And a lithium can be left partly discharge without harm.

[MickinOz]

That DoD is bulldust, do not go below 50% except rarely like in emergencies.

If you want AGM figure twice the price per Ah per year.

Heavy is good, indicator of quality for lead, AGM should **not** be lighter for the same Ah.

AGM will need much more precise infrastructure or get murdered early.

And yes T1 Terry was out of Mannum. But boat yard sparkies can put you on to others.

I started this thread just to canvass whether people have found AGM troublesome in a mobile situation.
My original question - who has had good/bad experiences with AGM?

I don't want AGM particularly, I just thought if people were having a trouble free run, maybe I could free myself from checking and topping up. I've done my time maintaining FLA battery banks, so AGM is tempting. If people have been getting a decent run out of them.

I've always felt FLA with plenty of head space for bulk electrolyte is the best, but free electrolyte in a timber box worries me a little.
You ain't lived until you've seen timber with sulphuric acid on it spontaneously ignite.

I've spent 44 years in the lead and lead alloys game, extracting it, purifying it, alloying it and assaying it. As a side-line, I've been involved in making the sulphuric acid that goes into them.
At last check 85% of our lead goes to the battery market still, and I do believe I know the difference between a starting battery and a deep cycle by now, and I have absolutely no intention of using a starting battery.

I mentioned starting batteries only to make the point that the FLA battery I'm looking at is the same brand as the starting batteries in my truck and boat, which I have had no trouble with, thus I think their deep cycle batteries should be OK, too.

The AGM I was considering is lighter because yes they do use less lead for a given capacity in VLRA batteries (there is a reason for itI can't remember right now) but also because it is actually a lesser capacity battery as well.

They do claim that AGM'c can discharge further than 50% without damage, not that I'd plan to do it ever, but it might make the 80 AH AGM more comparable to the 105AH FLA than might otherwise be the case.

BTW, when I said 80H is about the biggest I've seen, I meant in the standard, look like a car battery, format. I used to spend some time with a set of 1100 AH single cells.

I mentioned Exide just in passing reply to your comment nothing is made in Oz anymore.
When we still made them in Adelaide, South Australia, they were a brilliant battery, not inexpensive but very very robust and reliable.
Definitely the brand you chose for outback travel.

From your comments, maybe the US made ones aren't so good?
As for boat yard sparkies - there ain't one of them within 125 miles of me.

Having said all that, I reckon I'm going to go with the FLA - simply in terms of cost per watt hour.
I'll run it in a decent plastic box. It still slays me how many pictures I see of unprotected batteries sharing storage space with other stuff.
Drop one spanner, pair of barbecue tongs or tent peg across those terminals and see how you fare.

[John61CT]

Yes any battery regardless of chemistry needs proper securing, short protection etc.

But no, AGM is used worldwide, for House banks at least, far more than FLA, but it is not the smart choice economically unless one of their few advantages makes sealed necessary.

The **only** "troublesomes" is inability to access the electrolyte shorter life and finicky care requirements.

If those latter are done right, including a top brand like LifeLine, under 50% average DoD, they can last 6-8 years depending on how you define EoL, stretch to say 70% SoH.

Is that "a decent run" for you?

But I've seen many FLA banks last 13-15 years with apples to apples.

free electrolyte in a timber box worries me a little

Yes bare wood is not OK, Proper marine ply painted with acid-proof coating, or plastic is the norm.

> I mentioned starting batteries only to make the point that the FLA battery I'm looking at is the same brand as the starting batteries in my truck and boat, which I have had no trouble with, thus I think their deep cycle batteries should be OK, too.

Yes a common misconception. Optima was great when part of Gylling of Sweden, then they spun it off to JCI, meh! and now only a good Starter, not true deep cycling

> They do claim that AGM'c can discharge further than 50%

as already stated **that is a lie**, there is no magic "damage" boundary, but just look at the published "cycle lifespan vs avg DoD%" charts and all lead shows the same curve shape, just with better quality the absolute cycle numbers are shifted upwards.

Firefly Oasis has a **lower** ratio so 80% DoD is practical, but they are a unique patented formulation (Carbon Foam) and unaffordable to import into the ANZ market until a local distributor steps up (business opp there!).

Exide is fine as a Starter worldwide, but that isn't the topic here.

But yes with shipping such a huge part of the cost, small market's choices are very limited, lesser products appear better than in the bigger markets with top notch quality at $1 per Ah.

And yes it does further limit choices to be in a remote location, but even 2-300 miles is worth it IMO to get quality gear.

We used to drive 500+ each way for a day trip to the beach when I was a kid, but petrol's never getting that cheap again.

Did fill up last time at 96¢ though, Thanks COVID!

[MickinOz]

Exide is fine as a Starter worldwide, but that isn't the topic here

I had an Aussie made Exide deep cycle on my hunting cabin for years.
After I sold the property, I transferred that battery to my boat.
It gave up after about 3 years being used as a starting battery for a 60 horse Johnson.
Total life about 12 years, if I recall correctly, 3 spent being used for something it wasn't intended for.
Musta been the solar regulator I built myself.

A lot of people on stand alone power here won't touch AGM or Gel due to the far higher cost and shorter life.
Mate of mine had to replace individual cells several times, couldn't afford the whole bank in one go, and often bemoaned the fact he didn't get FLA.
I refrained from saying I told you so.

His was a DoD issue if ever I saw one. Three teenage kids managed to put that system on the generator every day.

BTW I'd be paying not much more than a $US dollar per AH for FLA at current exchange rates.

[Shadow Catcher]

I chose a Lifeline 150 AH 12 years ago as I did not want to have to water it or worry about out gassing. I replaced it with the same battery last year and am using the old one to power a battery back up sump pump. I was fed by a 185W high voltage panel through a Morningstar MPPT converter. When not on shore power it feeds a WAECO refrigerator, lights, chargers TV/DVD XM radio etc. We have never been below 64% SOC.

[John61CT]

Yes shallow cycling can double even triple lifespan.

But means you're carrying some "dead lead" around.

OTOH a Reserve can be very useful, especially solar-only living get a patch of many overcast days in a row.

[MickinOz]

I chose a Lifeline 150 AH 12 years ago as I did not want to have to water it or worry about out gassing. I replaced it with the same battery last year and am using the old one to power a battery back up sump pump. I was fed by a 185W high voltage panel through a Morningstar MPPT converter. When not on shore power it feeds a WAECO refrigerator, lights, chargers TV/DVD XM radio etc. We have never been below 64% SOC.

Ah, this is more like the sort of feedback I was hoping for.
Thanks for taking the time.
So you can get similar life to flooded wet acid.

I have a 250W panel, currently looking at decent MPPT regulators.
Victrons are fairly readily available, and the more I look the more value for money they look.

I found an online supplier for Lifeline AGM here in Oz.
100 AH Battery shipped is $821 Australian dollars.
I'm afraid, if it takes >20% of the materials costs of my teardrop to buy an AGM that can deliver similar life, then I'm going to have to skip it.
I can fit 4 x 105 AH FLA or 80AH Made in Australia AGM for that price, so economically it just doesn't stack up for me.

Again, thanks for taking the time to reply, it really does assist the decision for me.

P.S. 150AH Lifeline $1200 - definitely out of reach.

[John61CT]

what I said 8-(

But again, that extraordinary lifespan anecdote is explained by the shallow cycling

apples to apples, quality FLA (which by NA standards may not be affordable there either) will last much longer

plus really need CC load testing to see residual capacity, most owners push way past 70-80% SoH, only replace when explicit bad-performance symptoms arise,

by which time might be 5 years past standard EoL being proactive.

[MickinOz]

quality FLA (which by NA standards may not be affordable there either) will last much longer

Where exactly is it that you think we live?
I did get 12 years (3 as a starting battery) from an FLA, that was less than twice the price of an ordinary N70Z starting battery.
I'm beginning to think that you think if ain't American, it ain't any good.
News flash, there is whole world outside your borders.