Battery Craziness

[Canibul]

and golf cart batteries are SO easy to steal...

This lowers the cost enormously if you're careful.

[Ex-Calif]

The batteries supply power to the boat when generation systems cannot.

Batteries send amps out when needed and get restored by some charge system.

Some people have systems that "send" more amps to the boat per day than others becuase they go on the hook, let the batteries get lower before they run the gen etc.

Some folks with big solar, run the gen everyday etc. don't let the batteries discharge much.

So isn't the measure of battery life "How many amps were sent out of this battery until it failed" - The idea that it is calendar related does not really make sense. you need to know how hard the battery was "worked" and the measure of that is home many amps did it send out.

So an amp counter that can log the data to a PC makes sense in terms of battery value.

So if I plugged a charger into shore power that could supply all DC needs would the batteries last forever because they never discharge any amps?

Sorry to keep obsessing over batteries - It is a hypothetical question - but batteries do cost money and if I can lower the life cycle cost that is good, right?

[sailorboy1]

Originally Posted by Ex-Calif

Sorry to keep obsessing over batteries - It is a hypothetical question - but batteries do cost money and if I can lower the life cycle cost that is good, right?

Maybe. Depends on how much you value your long term stress level over worrying about your batteries. I have come to the point of feeling that not obsessing and only taking a moderate interest in my batteries is worth more than the $100/yr I might save.

You can save 100% of the cost of batteries if you want to, but is it worth it to you?

[Ex-Calif]

Originally Posted by sailorboy1

Maybe. Depends on how much you value your long term stress level over worrying about your batteries. I have come to the point of feeling that not obsessing and only taking a moderate interest in my batteries is worth more than the $100/yr I might save.

You can save 100% of the cost of batteries if you want to, but is it worth it to you?

Well maybe that's the heart of the matter. Everyone has a "boat bucks" tolerance. I find myself not obsessing over $100 items too much - hence just throw another $165 and get the BMV602 and the snartgauge. In the big scheme of things the only justification is that I "want it!"

Currently I have nothing - A cigarette lighter 3 LED guesstimator.

But if I am gonna spend $1500 on a bunch of crap that is in the bolge and behind panels I damn well want some blinking lights on my panel FFS so I can tell people about all my gee whiz gear in the bilge - LOL

In terms of batteries - I have 3 X 70 ampers. total about $400. Easily doable in a month's budget - Now a $1000 bank or $1500 bank or in some high cost region? On my budget that's is an expense worth fretting over...

Personal tolerances I think...

[a64pilot]

Batteries do die based on calender time, a battery sitting on a wooden bench connected to a battery tender will eventually go bad.
Deep discharge cycles will kill a battery too.
I hope to have a large enough bank one day to never go below 75% SOC, and enough solar to get to 100% SOC every day.

Funny thing is, we use probably at least 200% more power every day than we used to thirty or so years ago eventhough our devices are much more energy efficient, we just have many more "essentials" than we used to.

[sailorboy1]

Originally Posted by Ex-Calif

Well maybe that's the heart of the matter. Everyone has a "boat bucks" tolerance. I find myself not obsessing over $100 items too much - hence just throw another $165 and get the BMV602 and the snartgauge. In the big scheme of things the only justification is that I "want it!"

Well there you go, people obsess over their batteries for a SPORT

Applies to a lot of boat stuff where giving it all that extra love is meaningless. Kind of trying to make a cat like you more

[Dockhead]

Originally Posted by Kenomac

Replaced the battery bank on my Hunter 450 four years ago for $1300 purchased through Port Supply. Replaced our current set on the Oyster two years ago for $1800 in the UK.

I don't think I'd consider those prices cheap. Going to do my best to make them last. No solar, just genset and diesel.

Amen.

My present batteries cost over $2000.

Of course all batteries are expendable items which are used up every time you use them, but I don't think it's "crazy" to spend some effort trying to make them last.

Some cruisers hardly use their batteries; their boats live in a marina or a dock with shore power, and they sail mostly from marina to marina. I think now that THIS would be a better case for not obsessing about batteries.

But in my case, I spend about 1/3 of the year or 4 months on board, most of this "off the grid", since my mooring doesn't have shore power, and I spend more time at anchor than in ports. So for me, the number of cycles I get out of my batts is really pretty important to my bottom line operating costs.

I rationalize the cost based on the huge amount of money I save on marinas -- I was paying $20,000 a year for a marina berth before the Queen graciously gave me my little piece of heaven on the Hamble. You can buy a lot of batteries (and diesel fuel to run the generator!) on that kind of dosh.

But still.

[Canibul]

Originally Posted by Ex-Calif

The batteries supply power to the boat when generation systems cannot.

Batteries send amps out when needed and get restored by some charge system.

Some people have systems that "send" more amps to the boat per day than others becuase they go on the hook, let the batteries get lower before they run the gen etc.

Some folks with big solar, run the gen everyday etc. don't let the batteries discharge much.

So isn't the measure of battery life "How many amps were sent out of this battery until it failed" - The idea that it is calendar related does not really make sense. you need to know how hard the battery was "worked" and the measure of that is home many amps did it send out.

So an amp counter that can log the data to a PC makes sense in terms of battery value.

So if I plugged a charger into shore power that could supply all DC needs would the batteries last forever because they never discharge any amps?

Sorry to keep obsessing over batteries - It is a hypothetical question - but batteries do cost money and if I can lower the life cycle cost that is good, right?

So you're saying what actually matters is how many amps pass through their hands before they die.

[LakeSuperior]

Originally Posted by sailorboy1

I have come to the point of feeling that not obsessing and only taking a moderate interest in my batteries is worth more than the $100/yr I might save.

You can save 100% of the cost of batteries if you want to, but is it worth it to you?

What is worth extending battery life is; not having to remove 4 - 60 lb batteries from various cramped hot inaccessible compartments, carrying them through the boat, hoisting them up the companionway, walking them to the dock, and transporting them to where-ever for disposal. I guess you could just throw the old ones overboard on second thought. Then repeat the process in reverse with the new ones.

When install is complete you then throw away your favorite well broken in sailing shorts and best tee shirt because they have rotted off in the battery fumes and then start process of getting new shorts and tee shirts broken in to fit right and be comfortable.

[colemj]

Originally Posted by sailorboy1

Maybe. Depends on how much you value your long term stress level over worrying about your batteries. I have come to the point of feeling that not obsessing and only taking a moderate interest in my batteries is worth more than the $100/yr I might save.

You can save 100% of the cost of batteries if you want to, but is it worth it to you?

I think you are either discounting or unaware of the stress of finding, shipping and installing new batteries in certain parts of the world that make for fine cruising.

Like you, when we lived in the land of stuff and right next to one of the largest battery distributers in the US, we never stressed about our batteries.

Now, with the possibility of needing to change our insurance policy simply to sail 1000 miles to a place where we can order batteries from another place and have them shipped in by ocean freight taking 3-4 weeks - all while hoping to nurse along the existing system so we have refrigerated food and a bit of light at night…

Well, it is less stressful to obsess and take interest a bit about our batteries now.

Mark

[Ex-Calif]

Originally Posted by a64pilot

Batteries do die based on calender time, a battery sitting on a wooden bench connected to a battery tender will eventually go bad.
Deep discharge cycles will kill a battery too.
I hope to have a large enough bank one day to never go below 75% SOC, and enough solar to get to 100% SOC every day.

Funny thing is, we use probably at least 200% more power every day than we used to thirty or so years ago eventhough our devices are much more energy efficient, we just have many more "essentials" than we used to.

Exactly - One thing the boomers have done over the "traditionalists" is set higher expectation for convenience. Forget iPads and computers - It is not unheard of to have trash compactors, dishwashers, water makers and clothes washers on board. Not to mention entertainment systems and mulit-MFD nav stations.

Many of u are not calibrated to the paradigm and think it's ridiculous! Boat size will be picked not so much for bluewater capability but how many tons of batteries it can store.

At some point you just build in a diesel aux-gen - tank appropriately and run it all the time.

Originally Posted by Canibul

So you're saying what actually matters is how many amps pass through their hands before they die.

Sort of throwing it in the mix as I hadn't seen it discussed before - but yes - duty cycles is a strong indicator.

But as A64 points out the batteries will also die eventually when not used so the two failure mode lines co-exist - Dock queen batteries may die more from "age" - well used batteries from amp cycles and we know deeper cycles are probably worse so a correlation weak or strong on how many amps has the battery "given up" over its life could be a strong component.

It is more comparative than "My batteries lasted 3 years" - "My batteries lasted 7 years." The 3 year batteries may have coughed up 100 amps a day for 3 years and the 7 year one only 42 amps a day. In terms of life-amps provided they are the same.

[a64pilot]

Batteries that will live for years doing actual work, cycling almost daily have different construction than batteries that are built mostly to advertise a high amp capacity, in some respects a high amp capacity and long life not conducive to each other.

Batteries that live a long time
1. have thick plates that are well separated
2. have a considerable gap under the plates to allow a lot of material to build up before it makes contact with the plates and shorts them out.

High amp batteries usually
1. have more plates (in the same case) this means thinner plates that won't last as long
2. plates come closer to the bottom of the case as they are trying to maximize the surface area for more capacity, but of course they are more likely to have internal shorts as material build up under the plates.

[a64pilot]

Aircraft battery acid is different than regular battery acid in that it's specific gravity is higher, (acid is more concentrated)

I assume this is to give more capacity out of a lighter battery, but as there is no free lunch, I assume it also shortens the batteries life?

I don't know if this is true, but if it is would very slightly lowering the specific gravity of a batteries acid, lengthen it's life?

On edit, what I'm wondering is if we reduced the capacity of a battery by say 25% by using slightly diluted acid, would it now last 50% longer?

[IdoraKeeper]

Originally Posted by sailorboy1

Well there you go, people obsess over their batteries for a SPORT

Applies to a lot of boat stuff where giving it all that extra love is meaningless. Kind of trying to make a cat like you more

I agree with you about batteries but cats? Naw, the more you put into a cat the more biting and scratching you get back.

[DeepFrz]

Of course all batteries are expendable items which are used up every time you use them, but I don't think it's "crazy" to spend some effort trying to make them last.

Just like life itself.

Think electrical system folks. Batteries are just part of a whole system. Get the system right and you have comfort and convenience with little extra effort. Get it wrong and you will be forever tinkering.