Bought a new boat that needs new agms?

[Toccata]

Boat is a 46' Oceanic with centre cockpit, recently acquired.
It has 8 year old T 105s (x5)
Mounted alongside the engine, adequate engine room ventilation for proper engine operation, but still very warm in there.
The batteries are looking "pretty ordinary" now. The top of each battery is distorted, but still doing the job.
I have been planning to move to Li for the following reasons:
I can obtain similar AH out of one unit, that will weigh about %30 of the Trojan bank and so move it from the engine room to under the aft bunk, without greatly affecting hull trim. Cooler temps in there and it appeals to have 2018 technology replacing the old FLA batteries. The battery management system/solar panels/high output alternator, would seem to me to provide a robust charge option.
However following a KISS model and given the life obtained from the FLA, is there any consensus on staying with FLA batteries?

[a64pilot]

Firefly is supposed to be a game changer, especially compared to other AGM, probably is, but hard to source and real expensive.

Good ole fashioned vehicle traction batteries (Golf Cart) are relatively inexpensive and durable, tolerant of abuse, and in truth 95% of us abuse our batteries, they do not live the perfect life necessary for a lab derived lifespan. Only downside I see to them is you have to occasionally water them, but if that is too much of a chore, there are also special caps that make that a non event I believe.

Lithium, unless you have big bucks, love experimenting, and are darn near an Electrical Engineer wanna be, forget them for now.
It’s not the batteries, it’s the special support system that they require.
There will be I believe “kits” that will become available for those of us that don’t want the science experiment, we just want batteries that will work, but can read and follow directions. They will initially be really expensive I’m sure. So for those of us that just want our electrical system to work, without having to spend huge money and become an electrical systems expert, in my opinion regular ole lead acid batteries are for us, and every 5 or 6 years or so we will replace them

[Tim francis]

I read it. Lots of good info. It still confused me. I need to read it again

[john61ct]

Flooded Lead Acid

The ones with caps that pop off for topping up the water

let you get accurate SoC with a hydrometer

[john61ct]

How to learn jargon,

https://www.google.com/search?q=fla+...oq=fla+battery

GIYF

[john61ct]

Originally Posted by Tim francis

I was wondering about the solar controller issue also. I had 12.7 coming from the controller.

Means nothing with depleted batts.

But really, all charge sources should be user-adjustable so you aren't limited what chemistry bank to buy.

Take your time, You may find a better deal than those Trojans, but for Hawaii maybe that's a fair price.

Returns policy counts too.

Check the mfg date stamp, ideally recent and matching.

[Toccata]

In another life, I had a very electronically advanced power boat. It was fitted up with a Li battery bank and BMS
There were always small issues with the battery system.
I live in a remote place and could never quite translate instructions from the supplier/fitter into action.
So I found myself dependant on the supplier/installer for regular assistance and when it was time for an adjustment, it was not with a shifter and screwdriver, but rather hook in the lap top and adjust the settings. Note This was 10 years ago, but if running a Li system is still like this, I don't want it!
A consultation with a marine electrical supplier in Brisbane is pushing me back toward Li as a "bullet proof answer," but I have my doubts, particularly when there are enough doubts expressed in the CF on this very issue.

[hellosailor]

Tim-
Lifeline and Odyssey are somewhat unique both in price and in little differences, i.e. Lifeline AGMs can and should be equalized from time to time (you may need your Honda to do that) while most AGMs *must* not be.
In any case, you'll want a good MPPT controller, that gives you about 10-15% more power out of the solar panels and should also allow you to set the charging voltage to match what the battery maker says is correct for your batteries. And, a temperature sensor that goes on a battery and adjusts the controller for battery temperature will pay back in longer life and faster charging.
AGMs supposedly won't be happy or long-lived unless they get a full 100% charge every couple of days, so you need enough solar capacity (and the MPPT's gain helps that) to make sure they WILL be getting a full charge, and at some point they are regularly pushed up to "float" voltage.
You're right to "make haste slowly" on this, there are a lot of products with subtle (or unsaid) but important differences out there, and the good stuff never is cheap.

[Tim francis]

Yep lots of different advice from everything I’ve looked at. Seems I’ll go fla Trojan or us battery. Maui is already expensive but it’s nice to be able to be able to look at them in person. Amazon is cheaper but very limited choices due to shipping issues.

[admiralslater]

Coastal marine is selling drop in replacement Relion litium , each battery has its own built in bms. Not saying there great or anything but the concept is getting closer th usable every day.

[boatpoker]

Originally Posted by Tim francis

Aaaaaaa

Your photo shows two different types of battery. The blue ones look like AGM's. Is that the case ?

[Tim francis]

Yes the previous owner has two agm ad two fla. the starting battery is deep cycle too fla. he said two of the batteries were pretty new but don’t know which ones. I’m hoping after I replace the batteries the agms might still be good but planning on selling or giving the four batteries away. So I’m gonna pull the trigger I think and buy four fla probly is battery and a fifty amp battery charger I’ll use every couple days depending on amp usage via Honda 2000. If I run the charger on economy mode I get about 11 hours run time on one tank. I believe less than a gallon.

[boatpoker]

Originally Posted by Tim francis

Yes the previous owner has two agm ad two fla. the starting battery is deep cycle too fla. he said two of the batteries were pretty new but don’t know which ones. I’m hoping after I replace the batteries the agms might still be good but planning on selling or giving the four batteries away. So I’m gonna pull the trigger I think and buy four fla probly is battery and a fifty amp battery charger I’ll use every couple days depending on amp usage via Honda 2000. If I run the charger on economy mode I get about 11 hours run time on one tank. I believe less than a gallon.

Glad to hear you are changing to one type. Mixing types shortens battery life due to different required charging regimes.

You should also add fuse protection the the positive conductors and the batteries should be in trays/boxes to capture spilled electrolyte (suphuric acid).

Also hope there is ventilation in that compartment to allow the hydrogen gas to escape and dont not install a battery charger in that unventilated compartment with batteries.

[a64pilot]

I get right at 10 hours out of my Little Honda and I think it’s .9 gl.
Of course how much load you put it under determines how much fuel it burns, I have a big charger but turn it down to 50% so it will only charge at about 60 amps, which is about 8 amps AC, any more and the little Honda speeds up and gets loud.
The Honda base RPM is 3000 in eco, no load, and 4000 with eco off. It can turn up to 4300 though if the load is high, whether in eco or not.

Difference in eco on and off is in eco if starting load is high it can’t respond fast enough, voltage drops and it disconnects, eco off it can respond faster as it’s already at a high RPM

[davenrino]

Originally Posted by Tim francis

My plan is to buy four agm lifeline six volt batteries off amazon. Free shipping to Maui is key

I am afraid you may have to rethink the Amazon purchase. I just checked Amazon and the only batteries I found that would even ship to Hawaii were $900 ea and over $500 shipping. I can't even get Amazon to ship my little Harley battery to HI any longer, and yes I have Prime. Ebay however; is a different story. Good Luck.