Depth of Discharge Myth?

[evm1024]

Originally Posted by ramblinrod

1. Some with no solar are talking about switching to LiFePO4.

They will be forced to run ICE for ALL charging.

If the just added solar and/or wind to inexpensive FLA instead, they could avoid ICE charging most days. Total cost would be less. Avoid the noise and cabin heating of most days. Those with adequate wind and solar that motor sail to another anchorage every 2 or 3 days, rarely, rarely, rarely ever need ICE charging.

2. To compensate for the high cost of LFP batteries, some are omitting any reserve capacity over average daily consumption and solar/wind charge capacity.

If they have less wind or solar than their FLA counterpart, they will definitely be on ICE at 20% SOC, else risk damaging very expensive batteries. If their loads are 50% higher than average (which is certainly possible) they will be at 20% and need to run ICE in 13 hours.

Whereas if someone has FLA with the normal reserve capacity (so that they don't normally dip below 50%) then they can allow the bank to go down to 20% to meet the higher than usual load or lower than usual charge capacity. If there is a light load day or high wind/sun day to follow, they can just allow the bank to recharge without ICE.

SNIP

1. Some with no solar are looking for solutions to their defective Lead Acid system.

They are currently running ICE for ALL their charging.

If the just added solar and/or wind to cover their power usage, they could avoid ICE charging most days. By adding solar to their boat they can overcome the problem in their Lead Acid system. Solar would allow them to Avoid the noise and cabin heating of ICE most days. Those with adequate wind and solar that motor sail to another anchorage every 2 or 3 days, rarely, rarely, rarely ever need ICE charging.

Some realized that their FLA house bank just sucked so they added solar and switched to LiFePO4. They were willing to pay for peace of mind.

2. Because of the ability of LiFePO4 to use almost all of its rated capacity they are able to size the LiFePO4 bank most effectively. Some were using the lead acid capacity below 50% SOC as an emergency reserve capacity over average daily consumption and solar/wind charge capacity. This caused early lead acid failure and required expensive bank replacements every other year. Sometimes yearly.

If they have less wind or solar than their actual usage, they will definitely be using ICE to cover up their charging shortfall. With Lead Acid they in many cases significantly reduce the life of their lead acid bank while their friends who have LiFePO4 bank don't worry about killing their bank by under charging the bank or letting the SOC drop below 50%. If their loads are 50% higher than average (which is certainly possible) on the odd day they will be at 20% SOC and the LiFePO4 folks will just reduce the load or fire up the ICE for a short while. While their Lead Acid friends will be pulling their hair out and starting the ICE to attempt to get the LA bank up to 100% with 13 hours of ICE running time. They wonder if they can take the dinghy out to avoid the noise and heat of the ICE needed to save their batteries.

Whereas smart boaters build extra capacity into their house banks and know that 400 AH of LiFePO4 has more capacity then 800 AH FLA. Those with FLA know that their normal reserve capacity is only 1/4 the sticker capacity of their bank. They spend a lot of time making sure that they don't normally dip below 50% and it really worries them when their bank goes down to 20% to meet the higher than usual load or lower than usual charge capacity.

If there is a light load day or high wind/sun day to follow, they can just allow the bank to recharge without ICE. They know that the charge efficiency of FLA sucks so they do not count on solar and light load days to bring their bank back up to 100% SOC to avoid killing their bank so they plan on running their ICE to make up for the problems with lead acid. They wish they had LiFePO4 because it has a much greater CEF than FLA, does not need to be charged to 100% to get good life, Does not mind going to 20% SOC.

In short they wish they had lithium so that they could get rid of the Lead Acid ball and chain that interferes with their cruising enjoyment. That and the cold beer from the LiFePO4 powered fridge.

[newhaul]

So to summarize the jist of this thread .
Depth of discharge does affect the life expectancy of batteries regardless of chemistry.
Some are more apparent than others . Some do not suffer from PSOC conditions some do ( which is a quick killer)
some require lots more attention than others to maintain longevity between changes.
Each have advantages and disadvantages ( it seems to be mainly up front costs).
Everything else on this thread seems like for some to understand.

[ramblinrod]

Originally Posted by john61ct

Adding "wind and sun" capacity is easier said than done.

And not even desirable in many cases. Can't stand the vibration / noise from a wind unit myself.

Many are running ICE anyway, and just capturing that potential output more efficiently is often more than enough.

With LFP you get much shorter runtimes. And if you do keep some solar, capture more output from that as well.

I'm not saying worth it for everyone, nor even many owners.

Just trying to counter the constant and long-winded repetition of misinformation.

I have post no misinformation. None. Zero.

I don’t understand how one can mind the sound of solar charging. It makes no sound. The sound from a decent modern wind generator is negligible to the sound of an ICE powered alternator or generator, albeit to recharge 80 Amps, an ICE driven alternator of adequate size can generate that in a shorter period. With wind and solar combination (properly sized) , usually the bank will be charged adequately by noon, that wind can be shut down, and the bank topped off by silent solar.

[newhaul]

Originally Posted by ramblinrod

I have post no misinformation. None. Zero.

I don’t understand how one can mind the sound of solar charging. It makes no sound. The sound from a decent modern wind generator is negligible to the sound of an ICE powered alternator or generator, albeit to recharge 80 Amps, an ICE driven alternator of adequate size can generate that in a shorter period. With wind and solar combination (properly sized) , usually the bank will be charged adequately by noon, that wind can be shut down, and the bank topped off by silent solar.

the one caveat I see is the omission that this applies to all battery chemistry .
Some take better advantage of solar/ wind charger output throughout the entire charging cycle. Likely reducing the need for dino juice charging at all.

[ramblinrod]

Originally Posted by evm1024

Rod let me fix that for you:

1. Some with no solar are looking for solutions to their defective Lead Acid system.

They are currently running ICE for ALL their charging.

If the just added solar and/or wind to cover their power usage, they could avoid ICE charging most days. By adding solar to their boat they can overcome the problem in their Lead Acid system. Solar would allow them to Avoid the noise and cabin heating of ICE most days. Those with adequate wind and solar that motor sail to another anchorage every 2 or 3 days, rarely, rarely, rarely ever need ICE charging.

Some realized that their FLA house bank just sucked so they added solar and switched to LiFePO4. They were willing to pay for peace of mind.

2. Because of the ability of LiFePO4 to use almost all of its rated capacity they are able to size the LiFePO4 bank most effectively. Some were using the lead acid capacity below 50% SOC as an emergency reserve capacity over average daily consumption and solar/wind charge capacity. This caused early lead acid failure and required expensive bank replacements every other year. Sometimes yearly.

If they have less wind or solar than their actual usage, they will definitely be using ICE to cover up their charging shortfall. With Lead Acid they in many cases significantly reduce the life of their lead acid bank while their friends who have LiFePO4 bank don't worry about killing their bank by under charging the bank or letting the SOC drop below 50%. If their loads are 50% higher than average (which is certainly possible) on the odd day they will be at 20% SOC and the LiFePO4 folks will just reduce the load or fire up the ICE for a short while. While their Lead Acid friends will be pulling their hair out and starting the ICE to attempt to get the LA bank up to 100% with 13 hours of ICE running time. They wonder if they can take the dinghy out to avoid the noise and heat of the ICE needed to save their batteries.

Whereas smart boaters build extra capacity into their house banks and know that 400 AH of LiFePO4 has more capacity then 800 AH FLA. Those with FLA know that their normal reserve capacity is only 1/4 the sticker capacity of their bank. They spend a lot of time making sure that they don't normally dip below 50% and it really worries them when their bank goes down to 20% to meet the higher than usual load or lower than usual charge capacity.

If there is a light load day or high wind/sun day to follow, they can just allow the bank to recharge without ICE. They know that the charge efficiency of FLA sucks so they do not count on solar and light load days to bring their bank back up to 100% SOC to avoid killing their bank so they plan on running their ICE to make up for the problems with lead acid. They wish they had LiFePO4 because it has a much greater CEF than FLA, does not need to be charged to 100% to get good life, Does not mind going to 20% SOC.

In short they wish they had lithium so that they could get rid of the Lead Acid ball and chain that interferes with their cruising enjoyment. That and the cold beer from the LiFePO4 powered fridge.

Posted edited by moderator

The real deal is that most cruiser electrical energy needs can be satisfied by simply adding adequate charging sources to FLA battery systems, rather than switching to batteries 9 times the cost, only to find. their charging sources are still inadequate to avoid ICE charging.

Batteries do not generate electrical energy. They only store it.

[newhaul]

Originally Posted by ramblinrod

.

Batteries do not generate electrical energy. They only store it.

some store it faster than others. ( Lfp does)

[ramblinrod]

Originally Posted by newhaul

the one caveat I see is the omission that this applies to all battery chemistry .
Some take better advantage of solar/ wind charger output throughout the entire charging cycle. Likely reducing the need for dino juice charging at all.

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

[evm1024]

Originally Posted by ramblinrod

I have post no misinformation. None. Zero.

SNIP

We have different opininos on what misinformation is. From my viewpoint:


Everytime someone post partial information or misleading information they are posting misinformation.


Everytime someone cherry picks facts they are posting misinformation.


The list of misinformation goes on and on.


Using facts to support an opinion is not the same as using forming an opinion based on all the facts.

[john61ct]

Originally Posted by ramblinrod

I have post no misinformation.

That would be "posted".

> I don’t understand how one can mind the sound of solar charging. It makes no sound.

Trying to be funny?

> The sound from a decent modern wind generator is negligible

Not to me, constant background irritation.

An ICE running 6 hours a week is far preferable. For me.

> to recharge 80 Amps, an ICE driven alternator of adequate size can generate that in a shorter period.

That would need to be AH, amps makes no sense

[evm1024]

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

You keep posting over and over again because your assertions are not convincing. Your posting over and over again appears to be an attempt to beat other opinions down rather than to debate actual facts.


As for your credentials. I for one have praised your credentials. I do question you when you hold up your credentials and then speak with authority about things you do not have training on or experience with. I have asked that you establish the basis for your strongly help opinions that you appear to want to force on others.

[john61ct]

Originally Posted by newhaul

I still don't get the 9x cost statement please elaborate.

In NA market, cheaper FLA vs say a Victron LFP system, my last estimate was 5-7 times.

In other markets decent LFP systems cost only double or so.

Usable AH taken into account.

[newhaul]

Originally Posted by john61ct

In NA market, cheaper FLA vs say a Victron LFP system, my last estimate was 5-7 times.

In other markets decent LFP systems cost only double or so.

Usable AH taken into account.

I agree to a point what I am asking of rod is the actual cost of say 200 ah of Fla vs 200ah Lfp within his local resources market.

Lfp is much cheaper compared to Fla ah for ah in my local markets .
I'm in basically the boating capitol of North America.

[john61ct]

Systems: OceanPlanet (Lithionics), Victron, MasterVolt, Redarc (Oz specific?)

Bare cells: ​Winston/Voltronix, CALB, GBS, A123 & Sinopoly

I know of no other (acceptable to me) quality LFP vendors, and have never seen anything under $7-10 / AH delivered. Known-good seller, 100% sure New not seconds, with return policy and some support.

Comparing to $1 / AH Deka GCs is perhaps not fair, but then DIY LFP upgrading involves much greater infrastructure expense than just the cells.

So even going to $2/AH, and usable AH, still in the 5-7x ballpark.

[john61ct]

Originally Posted by newhaul

I'm in basically the boating capitol of North America.

Where the difference is most pronounced.

Europe and down under, not so much.

[newhaul]

Originally Posted by john61ct

Systems: OceanPlanet (Lithionics), Victron, MasterVolt, Redarc (Oz specific?)

Bare cells: ​Winston/Voltronix, CALB, GBS, A123 & Sinopoly

I know of no other (acceptable to me) quality LFP vendors, and have never seen anything under $7-10 / AH delivered. Known-good seller, 100% sure New not seconds, with return policy and some support.

Comparing to $1 / AH Deka GCs is perhaps not fair, but then DIY LFP upgrading involves much greater infrastructure expense than just the cells.

So even going to $2/AH, and usable AH, still in the 5-7x ballpark.

then there is the per cycle cost to consider as well
Maine sail spells it out quite well in this post http://www.cruisersforum.com/forums/...ml#post2709787