Lead acid or agm/gel

[Culwatty]

hi guys and Gals

Another battery thread sorry!

I searched and searched, but it appears that people are either sticking to LA or going straight for the LI I cannot afford the latter 🤔

So currently have numax dual purpose batteries 200ah house and 100ah for the starter.

Even under a 600w inverter to run smaller appliances they are struggling (will test them when I get the tester back here)

So I'm looking at replacement options, this boat has a sterling alternator controller and matched alternator, I also have two 175w solar panels that I will need a controller for agm and a Rutland 914i wind generator and controller that can already do agm.

3kw ring Pro inverter

Honda 2.7 kva frame generator (plan on installing this inside a locker with forced air vents when running)

Also a small 4 stroke inverter generator as a backup ( it was dirt cheap as a non runner and I fixed it)


My aim is to reduce my costs for future travel (post lockdown) I will be fitting an induction cooktop and very small electric oven (won't be used much but nice to have)

Generator is hopefully only going to be used when I am seeing high loads or bad weather

My main thoughts are that a good agm claims to have
600 cycles @50% DOD £259
Vs
lead acid 100 cycles @50% DOD £120

Both 120ah with a good discharge rates

Will most likely add another 2/3/ batteries in the following months as I rewire the interest boat

Now reading this back to myself I cannot see a problem but, I am not an experienced liveaboard in the respect of doing it myself I spent a year with family, cruising around florida and the gulf of Mexico

I have lived in vans, tents, and out of my pack so not unfamiliar with the lifestyle 😁😁

So can anyone see anything I have missed? Apart from the lotto ticket 😂

[two-rocks]

Gas generators, in boxes, fuel and fume issues? I’d pass. Noise, exhaust, maintenance.....yeah, not for me ��

More solar, and if you do the math-cooking will use more amps than you can replace factoring in refrigerators and whatnot.

Having just put LiFePO4 in, I’m not sure the disposable batteries make life any less costly - just cost spread out over time. The smaller banks will sputter and complain with a large inverter- making replacement more frequent.

For your situation look at cost per cycle, vs depth of discharge, vs c-rate, the added time to top off any lead acid battery and if you will linger in partial state of charge.

Agm is lead acid, fyi.

[Bill O]

Would look at 6V golf cart batteries for the house instead of dual purpose

[Pete7]

Originally Posted by Culwatty

3kw ring Pro inverter

Honda 2.7 kva frame generator (plan on installing this inside a locker with forced air vents when running)

I think these two items are your problem. There is a reason for gas on smaller yachts. Its cheap and available the world over, just needs sensible precautions.

The generator inside a locker, hmm I think you should re-think that one.

https://www.bbc.co.uk/news/uk-england-cumbria-34637493

It you cook on gas and heat with diesel, you don't need the big generator and everything becomes so much simpler. After all, why run a petrol generator to enable induction cooking, why not just use gas?

Pete

[a64pilot]

Flooded is cheapest and last a long time, but requires maintenance.
AGM can last decently long, but quality ones are expensive and theoretically will charge faster at least initially so less generator run time, but is maintenance free and will supposedly allow large loads, like cooking.
Gel is most expensive and lasts the longest, but you have to be spot on with charging, no cheap non programmable charge sources, and won’t take a large charge so generator run times will be longer, and from talking to most cruisers, their gel banks didn’t really last longer than flooded banks, if they use their banks heavily.
My belief is that Gel banks are very good for people who have large banks and only use a fraction of its capacity and have relatively low electrical demands and mostly charge by Solar, if done like that they have lasted for a decade or longer, but if you hammer them by cooking electrical and or discharge them close to 50% daily etc, they don’t last so long.

I think my next bank may be the Firefly, lots of hype, but they seem to live up to most of it? Only question still not answerEd is longevity. But they are Hello expensive, over $5 and AH here in the US, where a good quality flooded battery can be had for $1 an AH.

By they way, do NOT try to build in a portable generator, that’s as logical as trying to turn a Sportfishing boat into a sail boat, it is full of problems and is unsafe.
Sell it and buy a Honda 2200 and do not try to build it in, but you can run it for many hours if you hook it up to an outboard fuel tank.
Of you are going to be electrical cooking etc., I believe there is logic in having a spare generator. Honda’s are extemely reliable, but everything can break.

[Boatguy30]

How much power are you using? That is the question. I have roughly the same, but just 2 T105s. Same solar 500 watt inverter with USB to run TV, DVD and small vacuum.
Have a very efficient fridge and freezer. Almost never (once every few years) run a Honda EU1000 and a battery charger.

The key is to minimize your daily amp/hr and then the rest is easy.

[Culwatty]

Originally Posted by two-rocks

Gas generators, in boxes, fuel and fume issues? I’d pass. Noise, exhaust, maintenance.....yeah, not for me ��

More solar, and if you do the math-cooking will use more amps than you can replace factoring in refrigerators and whatnot.

Having just put LiFePO4 in, I’m not sure the disposable batteries make life any less costly - just cost spread out over time. The smaller banks will sputter and complain with a large inverter- making replacement more frequent.

For your situation look at cost per cycle, vs depth of discharge, vs c-rate, the added time to top off any lead acid battery and if you will linger in partial state of charge.

Agm is lead acid, fyi.

Yes I had electric cooking in the motor home and the twin hob pulled a good few amps, devils advocate, the hobs and ovens flick on and off at temp so its not a constant draw, admittedly the motor home had 3kw solar and 1100ah battery bank..... ha

Yes generator is for backup use only, or to top up batteries while cooking or welding on the boat (have yet to see if my tig will be happy with it I know its a risk but its worth it to me

OK thanks for the input I think a spreadsheet will help me get my ah usage on paper and see what I really need to be able to produce!

[a64pilot]

When you do your spread sheet. Realize there are inefficiencies at both ends, meaning of course you will need to make about 25% more power than you use. People will balk at that number but it’s about right if charging and inverter losses, plus perkeuit (sp) is taken into account when your cooking etc.

[Culwatty]

Originally Posted by Bill O

Would look at 6V golf cart batteries for the house instead of dual purpose

I will look into it!

Originally Posted by Pete7

I think these two items are your problem. There is a reason for gas on smaller yachts. Its cheap and available the world over, just needs sensible precautions.

The generator inside a locker, hmm I think you should re-think that one.

https://www.bbc.co.uk/news/uk-england-cumbria-34637493

It you cook on gas and heat with diesel, you don't need the big generator and everything becomes so much simpler. After all, why run a petrol generator to enable induction cooking, why not just use gas?

Pete

The idea being that I can run the induction from the batteries, I did so on a larger scale on my motor home, but that had a big battery bank and 10x the solar so hardly noticed it!

The generator is more for backup charging, or bad weather, or if I need to weld on the boat (there is quite a bit I need to weld)

I would ideally like to get rid of gas completely, camping gas bottles are around £25-30 each, people are reporting around 3 weeks a bottle. That's expensive! Where as solar is only cost of maintenance after purchase...

Originally Posted by a64pilot

Flooded is cheapest and last a long time, but requires maintenance.
AGM can last decently long, but quality ones are expensive and theoretically will charge faster at least initially so less generator run time, but is maintenance free and will supposedly allow large loads, like cooking.
Gel is most expensive and lasts the longest, but you have to be spot on with charging, no cheap non programmable charge sources, and won’t take a large charge so generator run times will be longer, and from talking to most cruisers, their gel banks didn’t really last longer than flooded banks, if they use their banks heavily.
My belief is that Gel banks are very good for people who have large banks and only use a fraction of its capacity and have relatively low electrical demands and mostly charge by Solar, if done like that they have lasted for a decade or longer, but if you hammer them by cooking electrical and or discharge them close to 50% daily etc, they don’t last so long.

I think my next bank may be the Firefly, lots of hype, but they seem to live up to most of it? Only question still not answerEd is longevity. But they are Hello expensive, over $5 and AH here in the US, where a good quality flooded battery can be had for $1 an AH.

By they way, do NOT try to build in a portable generator, that’s as logical as trying to turn a Sportfishing boat into a sail boat, it is full of problems and is unsafe.
Sell it and buy a Honda 2200 and do not try to build it in, but you can run it for many hours if you hook it up to an outboard fuel tank.
Of you are going to be electrical cooking etc., I believe there is logic in having a spare generator. Honda’s are extemely reliable, but everything can break.

Much appreciated, link understood! I would not have done it in such a way as failure would allow any gasses into the saloon, but I do see your point!

So its between the agm and flooded still its a tough choice, gel batteries will be less likely to fail at higher latitudes im guessing?

The generator is only for backup and welding work, battery's will hopefully be charged from the solar and I may make a tow behind generator....

Right now as its warm, I cook for dinner, few hot cuppas, and then just charging devices. Small rechargeable vacuum stays on charge as its in use a lot... washing machine is only a 300w twin tub few hours a month. Lights are all led

How much does an autohelm wheel steering unit use worst case I wonder?

Originally Posted by Boatguy30

How much power are you using? That is the question. I have roughly the same, but just 2 T105s. Same solar 500 watt inverter with USB to run TV, DVD and small vacuum.
Have a very efficient fridge and freezer. Almost never (once every few years) run a Honda EU1000 and a battery charger.

The key is to minimize your daily amp/hr and then the rest is easy.

I'm missing a terminology here, T105S ?

Yes looking at top loading small fridges. I bought marine before and turned out it was designed for tropical climates, but marketed in the UK. Forever throwing food out. Or thawing it out! Hahah

I can't really shrink the generator any more because of the welder ....



Thanks guys!

I think I need to spreadsheet all the number and work out what I want to do, will report back

[kas_1611]

Maybe I'm missing something but why the extra generator(s)? You have a large diesel engine with a big alternator, isn't that enough generation?


Why not invest in a much larger house bank, say at least 4x 120amp-hr batteries in parallel to give you almost 500amp-hrs (OK 250amp-hrs at 50% DOD) and more solar capacity. I have seen 200amp-hr L/A or AGM batteries available which would increase your storage capacity without overly increasing the footprint.

That would get rid of the need to carry extra petroleum for the generator, reducing the explosion and fire risks.

if you can afford AGM then go with them as they can withstand much higher heel angles, last a long time, can be discharged slightly deeper than their L/A cousins and you don't need any fancy charge controllers as most will adjust easily.

[Captain Puget]

2 thoughts -

- the carbon foam / Firefly batteries very simple and forgiving. Going on 4 years and no problems.

- reduce fuel diversity. I’ve chosen to cook and heat with diesel (except for barbecue), with a single gas hot plate for backup (the little high arising can type). Also I’ve moved to electric for the dingy motor. No gasoline onboard, less flammability and carbon monoxide risk.

[noelex 77]

Originally Posted by Culwatty

So can anyone see anything I have missed?

Propane/butane is not the ideal fuel on a boat, so I can understand the desire to move over to electric cooking. Personally, we only use propane/butane for a small percentage of cooking. However, you need to understand that electric cooking uses lots of power and this power needs to be produced.

If you are planning to be away from shore power for a reasonable percentage of the time, 350w of solar combined with a small wind generator and 200 AHr of battery capacity is not enough to consistently sustain electric cooking together with the other house demands.

You are likely to need significant run times on the petrol generator. I don’t think this is an improvement over the traditional propane/butane arrangement . In fact, with the drawbacks of a petrol generator such as noise etc it is a significant step backwards.

Electric cooking is great, but you need a large solar array and battery bank (or a marine diesel generator) to make this viable.

Anyway, good luck with whatever you decide, but at least consider retaining the propane/butane system (if it is not too late). Camping gaz bottles are too small for full time cruising so you need a system that uses much larger bottles.

If you are unsure consider a combination of electric and propane/Butane cooking depending on the available electrical power available. This reduces the biggest frustration of propane, which is arranging replacement bottles in a world that has no universal standards.

[MJH]

Originally Posted by Culwatty

hi guys and Gals

Another battery thread sorry!

I searched and searched, but it appears that people are either sticking to LA or going straight for the LI I cannot afford the latter ��

So currently have numax dual purpose batteries 200ah house and 100ah for the starter.

Even under a 600w inverter to run smaller appliances they are struggling (will test them when I get the tester back here)

So I'm looking at replacement options, this boat has a sterling alternator controller and matched alternator, I also have two 175w solar panels that I will need a controller for agm and a Rutland 914i wind generator and controller that can already do agm.

3kw ring Pro inverter

Honda 2.7 kva frame generator (plan on installing this inside a locker with forced air vents when running)

Also a small 4 stroke inverter generator as a backup ( it was dirt cheap as a non runner and I fixed it)


My aim is to reduce my costs for future travel (post lockdown) I will be fitting an induction cooktop and very small electric oven (won't be used much but nice to have)

Generator is hopefully only going to be used when I am seeing high loads or bad weather

My main thoughts are that a good agm claims to have
600 cycles @50% DOD £259
Vs
lead acid 100 cycles @50% DOD £120

Both 120ah with a good discharge rates

Will most likely add another 2/3/ batteries in the following months as I rewire the interest boat

Now reading this back to myself I cannot see a problem but, I am not an experienced liveaboard in the respect of doing it myself I spent a year with family, cruising around florida and the gulf of Mexico

I have lived in vans, tents, and out of my pack so not unfamiliar with the lifestyle ����

So can anyone see anything I have missed? Apart from the lotto ticket ��

Keep it simple...start from the beginning. Complete an electrical use survey to see what your daily electrical needs are. See where you can reduce your electrical needs thereby reducing battery size. Select the battery chemistry for your lifestyle that you will maintain properly...go for the long term cost/amp. Use more solar to maintain them. Forget the generators, induction cooktop, and electric oven...use propane.

~ ~ _/) ~ ~ MJH

[MAJICDAN]

100 cycles led acid??? That is only three months!!!
600 cycles AGM??? That is less than two years.
I have two house battery banks of 10 size 31agm deep cycles and 10 golf cart batteries because of their size.
I have used cheap Sams golf cart batteries for the last five years and am just thinking about replacing them.
I am on my second and third set of AGMs
The golf cart batteries cost 1/3 of AGM and have lasted over twice as long.
Plus the AGM would suddenly go bad
I had three AGM failures in the last six months while in the Virgin Islands
The golf cart batteries all still work but have all diminished equally
To start with you will need twice as many batteries as you think so you do not drain them down so low.
AGMs you can not easily test.
I take the temperature of each AGM each month.
I test the specific gravity of each golf cart battery cell every month and fill them with distilled water.

[Starbuck]

The OP, he say:

I'm missing a terminology here, T105S

Culwatty, The Trojan T-105 is a 6-volt, deep-cycle, flooded lead acid battery that many in the cruising community promote as, arguably, the standard to compare all others by. Two are wired in series to create a 12-volt battery; two or more of these pairs are then wired together in parallel to achieve the desired house bank capacity, in terms of amp-hours.