Depth of Discharge Myth?

[newhaul]

Originally Posted by kmacdonald

I think it's because of charging issues. Can solar charge controllers be programmed to shut off instead of going to float?

Being able to program a bulk and absorption voltage is grossly inadequate with lithium. It falls way short of what is needed.

that's exactly what my PWM unit does

[ramblinrod]

Originally Posted by john61ct

> Shorter run times of ICE will be the biggest advantage of LiFePO4 for some people and the cost savings could be enormous.

Only if ICE is the major charging method.

For a typical cruising boat, implementing adequate wind and solar charging capacity will likely represent lower initial cost and higher ongoing cost savings than FLA to LFP transition.

With adequate wind and solar, LFP transition would be a terrible financial investment; enormous cost for little to no benefit.

Plus, solar is silent, wind can be nearly so, neither polutes, nor heats up the cabin, and eliminates dependency on fuel supply for charging purposes.

[kmacdonald]

Originally Posted by newhaul

that's exactly what my PWM unit does

When and how does it come back on?

[kmacdonald]

Didn't Maine Sail say he no longer supports or consults lithium installs? What do you think the reason is for that?

[newhaul]

Originally Posted by kmacdonald

When and how does it come back on?

battery voltage sense .2 or .3 volt during daylight hours.

[newhaul]

Originally Posted by ramblinrod

Only if ICE is the major charging method.

For a typical cruising boat, implementing adequate wind and solar charging capacity will likely represent lower initial cost and higher ongoing cost savings than FLA to LFP transition.

With adequate wind and solar, LFP transition would be a terrible financial investment; enormous cost for little to no benefit.

Plus, solar is silent, wind can be nearly so, neither polutes, nor heats up the cabin, and eliminates dependency on fuel supply for charging purposes.

this thread is about depth of discharge regardless of chemistry not about Fla vs Lfp

[john61ct]

Originally Posted by ramblinrod

Only if ICE is the major charging method.

For a typical cruising boat, implementing adequate wind and solar charging capacity will likely represent lower initial cost and higher ongoing cost savings than FLA to LFP transition.

With adequate wind and solar, LFP transition would be a terrible financial investment; enormous cost for little to no benefit.

Plus, solar is silent, wind can be nearly so, neither polutes, nor heats up the cabin, and eliminates dependency on fuel supply for charging purposes.

Yes, all irrelevant to the point I was agreeing to, and all repeated by you over a dozen times already.

Another way to phrase the same thing: If you will regularly be burning dino juice for other reasons, LFP can remove any need to also install annoying and awkward wind and solar apparatus.

[newhaul]

Originally Posted by john61ct

I had not come across that.

I do know he's always turned down work for obstreperous or otherwise unmanageable clients who appear uninclined to take directions well enough to ensure successful ongoing operations of the systems.

yep it was in one of his Lfp posts had something to do with people not strictly following his advice and trying to turn it back on him when things went sideways. At least that's how interpreted his postings.

[senormechanico]

Originally Posted by ramblinrod

Again, and I repeat myself only because others, keep posting the same stufff...


On a normal day, with adequate wind and solar generation, FLA batteries may meet the electrical energy storage requirements ds perfectly adequately.

Solar is great. The output typically drops near the end of re day to reasonable
Match the reduced acceptance of the FLA batteries.

If one has adequate charging to meet electrical demand, the real advantage to LFP is about 50% weight reduction, A-hr for A-hr, at a cost of about 9’times as much, if you are talking quality LFP and not China crap.

I see that you have posted all kinds of disparaging remarks about my credentials and experience (that in reality is vastly superior to your own) and yet you have not answered the simple question, “What is the brand of
LFP you have installed (one installation on your personal boat). If

Are you sure you're not a lawyer?

If you're not, you missed your calling !

[Dockhead]

Originally Posted by ramblinrod

Only if ICE is the major charging method.

For a typical cruising boat, implementing adequate wind and solar charging capacity will likely represent lower initial cost and higher ongoing cost savings than FLA to LFP transition.

With adequate wind and solar, LFP transition would be a terrible financial investment; enormous cost for little to no benefit.

Plus, solar is silent, wind can be nearly so, neither polutes, nor heats up the cabin, and eliminates dependency on fuel supply for charging purposes.

You keep saying that, and everyone recognizes the great benefits of solar, but again, solar has its own very serious drawbacks and is not a solution which everyone can use, or wants to use.



You keep saying that LFP is a "terrible financial investment", "throwing away money", etc., etc., etc., but that is not true for everyone. How LFP stacks up financially varies greatly depending on the use case and market.



These categorical blanket statements don't really advance the discussion. Others are exploring the pluses and minuses on a much deeper level.

Originally Posted by ramblinrod

If one has adequate charging to meet electrical demand, the real advantage to LFP is about 50% weight reduction, A-hr for A-hr, at a cost of about 9’times as much, if you are talking quality LFP and not China crap.

Where do you get this stuff and why do you keep repeating it? What is "quality LFP"? ALL LiFePo4 is made in China, including the cells repackaged by Victron and Mastervolt and marked up by 300%. The Winston and CALB prismatic cells are top notch, comparable to Rolls or Lifeline in lead, and not "Chinese crap". In my market they cost less than double per usable amp/hour compared to even mid-priced lead (not 9x), and last maybe 10 times longer depending on the use case.


No, lithium is certainly not for everyone, and are certainly not for the non-technically competent owner, but a significant number of cruisers are having great experiences with such systems, and are even saving money.




And another way to look at the financial side of it -- if it really WERE a question of adding solar, as you keep saying (putting aside the issue of many cruisers not being able or willing to put solar panels on their boats) -- what does the cost of that compare to changing to lithium, for a boat which already has excellent internal combustion charging? Lithium then will likely be substantially cheaper in terms of capital cost, besides running cost.


Everyone has got to make his own analysis for his own particular boat and cruising style. There is no one right solution for everyone, and there is no such thing as the "average cruising boat". Average weekend use on the lake is something very different from average in the Caribbean which is different again from average for long distance voyagers, and small is very different from large.

[Dockhead]

Originally Posted by john61ct

. . . Another way to phrase the same thing: If you will regularly be burning dino juice for other reasons, LFP can remove any need to also install annoying and awkward wind and solar apparatus.

Yes, that is ONE very good use case for lithium. There are others, too.



Lead and solar go great together (provided you can get enough capacity). In many use cases solar (perhaps in combination with internal combustion) might remove the awful finishing charge problem of lead.



Lithium and internal combustion go great together. Lithium, especially in combination with enough charging capacity, can enormously increase the efficiency of using internal combustion to produce power, especially, power produced incidentally to propulsion.

[ramblinrod]

Originally Posted by Dockhead

You keep saying that, and everyone recognizes the great benefits of solar, but again, solar has its own very serious drawbacks and is not a solution which everyone can use, or wants to use.



You keep saying that LFP is a "terrible financial investment", "throwing away money", etc., etc., etc., but that is not true for everyone. How LFP stacks up financially varies greatly depending on the use case and market.



These categorical blanket statements don't really advance the discussion. Others are exploring the pluses and minuses on a much deeper level.









Where do you get this stuff and why do you keep repeating it? What is "quality LFP"? ALL LiFePo4 is made in China, including the cells repackaged by Victron and Mastervolt and marked up by 300%. The Winston and CALB prismatic cells are top notch, comparable to Rolls or Lifeline in lead, and not "Chinese crap". In my market they cost less than double per usable amp/hour compared to even mid-priced lead (not 9x), and last maybe 10 times longer depending on the use case.


No, lithium is certainly not for everyone, and are certainly not for the non-technically competent owner, but a significant number of cruisers are having great experiences with such systems, and are even saving money.




And another way to look at the financial side of it -- if it really WERE a question of adding solar, as you keep saying (putting aside the issue of many cruisers not being able or willing to put solar panels on their boats) -- what does the cost of that compare to changing to lithium, for a boat which already has excellent internal combustion charging? Lithium then will likely be substantially cheaper in terms of capital cost, besides running cost.


Everyone has got to make his own analysis for his own particular boat and cruising style. There is no one right solution for everyone, and there is no such thing as the "average cruising boat". Average weekend use on the lake is something very different from average in the Caribbean which is different again from average for long distance voyagers, and small is very different from large.

I am not making categorical blanket statements.

Quite the comtrary I was responding to one that was.

I clearly identified the circumstance where LFP would and would not be a waste of money, and detrimental to comfort, and where wind and solar on FlA will likely be a better choice then FLA to LFP transition.

[Delfin]

Originally Posted by Dockhead

Lithium and internal combustion go great together. Lithium, especially in combination with enough charging capacity, can enormously increase the efficiency of using internal combustion to produce power, especially, power produced incidentally to propulsion.

Well put. On my stinkpot our routine when cruising frequently involves going 30 or 40 miles a day to the next beautiful anchorage. On those days, running the genset and main to do laundry, make water, bake bread and charge our Lithium bank all happens as once, and we usually turn off the genset after 90 minutes or so because the Lithium bank is full, the laundry is done and we have enough water. On the days when we stay an anchor I have to run the genset 3 hours or so. With my former AGM bank, to fully recharge that would be around 7 hours. Festooning the boat with solar panels and listening to wind generators 24 hours a day just isn't part of our program.

Our cruising profile may not be others, but it is the same as about a thousand boats here in the PNW and for those boats, Lithium is a clear winner, assuming they spend a lot of time away from the dock, and lots of great places there aren't docks.

Re: the main point of this thread - DoD is directly related to longevity, regardless of chemistry. While you can discharge LA below 50%, you pay the price in reduced longevity, or so testing would indicate. In my experience, discharging no lower than 40% and then fully recharging means LA batteries will last a very long time, but to do that, you either run a genset or engine a very long time, or you have a floating solar factory on board, or you live without using much electricity. Blanket statements that LA + solar + wind are the only rational choice is nonsense, but to each his own.

[ramblinrod]

Originally Posted by Delfin

Blanket statements that LA + solar + wind are the only rational choice is nonsense, but to each his own.

Has anyone made that blanket statement?

I know I haven't.

I don't think anyone has.

I suspect most people sharing an anchorage wish everyone would use silent solar and/or near silent wind to charge their batteries (regardless of battery technology).

For those disinclined to apply these charging technologies in favour of noisy, smelly ICE charging, I suspect boaters do hope they change out FLA batteries for LiFePO4 to reduce ICE running time.

However this doesn't likely change that they really wish those people would reduce or eliminate unnecessary ICE running by applying solar and/or wind charging systems.

Sometimes, the choices one makes can affect others beyond the confines of their own hull.

A while back, we were in a quiet and peaceful anchorage (Prinyers Cove for anyone who knows it), when a boat with "first rights" smack in the middle of the anchorage, raised anchor in the evening and moved away to the outskirts of the anchorage to run their generator without disturbing others.

Very courteous.

If all were so considerate, there prolly wouldn't be near the objection to those choosing to charge with ICE rather than with wind and/or solar.

[a64pilot]

Originally Posted by john61ct

I agree.

Everyone please remember "BMS" refers to certain functionality.

No, it doesn’t.
It’s an acronym for “battery management system” that is all.
You can be a BMS if you so desire or you can have electronics do it.
There is no set definition of what a BMS is, it can be anything at all, from a full blown battery management system that controls everything , or it can be just simply a safety disconnect, although that is not normally a BMS, that is merely a safety disconnect.

Here is one definition of a BMS and I’d say a pretty much industry wide definition.
https://en.m.wikipedia.org/wiki/Batt...agement_system