LiFePO4 (Redodo or Eco-worthy)

[CaptainRivet]

Originally Posted by s/v Jedi

Things are what they are. The forum doesn’t care about content providers, never really did and simply doesn’t deserve the content. Most who were like me are long gone and I now stay around for entertainment and to help others… but more and more I find that a lost cause as well because people only want to hear they did good even when they didn’t and are clueless

I agree with you on that. Which forum cares about content?

[s/v Jedi]

Originally Posted by CaptainRivet

I agree with you on that. Which forum cares about content?

They care about the content because it generates clicks so income. They don’t care about where it comes from, as long as it’s free or cheap and as a content provider, I really feel why all the others left.

[Fuss]

The forumite that learns the most and gets the most benefit is you Rivet. It enables you to gain knowledge and then go on to advise all the others and stop them being clueless. So the forums are really useful.

[CaptainRivet]

Originally Posted by Fuss

The forumite that learns the most and gets the most benefit is you Rivet. It enables you to gain knowledge and then go on to advise all the others and stop them being clueless. So the forums are really useful.

Yes i never stop learning. Well i learned here mostly how not to do things...but also that is valuable.
But Jedi is right the balance what he and also i gain versus what he and I deliver is way out.
I definitely not be the one who gets the most benefit...i don't care about that as long as i see a benefit its fine.

[seaexplorer]

I have extensive experience with both Lithium Ion and LiFePO4 batteries in both marine and non-marine contexts.

I have a number of suggestions;

1. For GRP or wooden boats ONLY LiFePO4 should be considered as they are far less flammable, less likely to have thermal runaway and can be extinguished with salt water.

For aluminium boats where you can make a sealed aluminium compartment (5mm plates minimum) which is part of the main aluminium structure of the boat exclusively for the batteries with an exit for hot gasses Lithium Ion can be considered. It is possible to have a massive lithium fire in that compartment with zero damage to the rest of the boat.

This is because of the superior fire safety characteristics of aluminium:

1) Higher melting point than temp of lithium fires;
2) Very high thermal conductivity - safely transfers heat of fire to rest of hull and into the water;
3) Very high thermal reflectivity - reflects heat of the fire away;
4) Very high thermal emissivity - emits heat of fire away into air and water (ensure nothing flammable directly against other side of special lithium compartment for this reason.

2. Almost all lithium cells come from China but there are differences in quality.
There are many sources of high quality batteries with good BMS with Victron Cerbo connectivity and sometimes bluetooth. The prices can be 1/5th of the big brand batteries.

3. It is a bad idea to have any automatic disconnection of 'house' loads (as opposed to propulsion loads) LiFePO4 batteries by the BMS. The danger of losing power for critical systems at a the worst moments is far greater than the non-existent chance of thermal runaway of LiFePO4 batteries in a house application (where current draws are relatively low). The only risk is dead shorts and this is better dealt with by DC-DC converters.
Even for propulsion applications it is questionable whether automatic disconnection is a good idea.

4. The risk of dead shorts from equipment failure or wiring problems is eliminated by the use of isolated DC-DC converters which prevent short circuits be galvanically isolating the battery from its loads. This can also vastly reduce the need for fuses, which always blow at inconvenient times.

[CaptainRivet]

Originally Posted by seaexplorer

I have extensive experience with both Lithium Ion and LiFePO4 batteries in both marine and non-marine contexts.

I have a number of suggestions;

1. For GRP or wooden boats ONLY LiFePO4 should be considered as they are far less flammable, less likely to have thermal runaway and can be extinguished with salt water.

For aluminium boats where you can make a sealed aluminium compartment (5mm plates minimum) which is part of the main aluminium structure of the boat exclusively for the batteries with an exit for hot gasses Lithium Ion can be considered. It is possible to have a massive lithium fire in that compartment with zero damage to the rest of the boat.

This is because of the superior fire safety characteristics of aluminium:

1) Higher melting point than temp of lithium fires;
2) Very high thermal conductivity - safely transfers heat of fire to rest of hull and into the water;
3) Very high thermal reflectivity - reflects heat of the fire away;
4) Very high thermal emissivity - emits heat of fire away into air and water (ensure nothing flammable directly against other side of special lithium compartment for this reason.

2. Almost all lithium cells come from China but there are differences in quality.
There are many sources of high quality batteries with good BMS with Victron Cerbo connectivity and sometimes bluetooth. The prices can be 1/5th of the big brand batteries.

3. It is a bad idea to have any automatic disconnection of 'house' loads (as opposed to propulsion loads) LiFePO4 batteries by the BMS. The danger of losing power for critical systems at a the worst moments is far greater than the non-existent chance of thermal runaway of LiFePO4 batteries in a house application (where current draws are relatively low). The only risk is dead shorts and this is better dealt with by DC-DC converters.
Even for propulsion applications it is questionable whether automatic disconnection is a good idea.

4. The risk of dead shorts from equipment failure or wiring problems is eliminated by the use of isolated DC-DC converters which prevent short circuits be galvanically isolating the battery from its loads. This can also vastly reduce the need for fuses, which always blow at inconvenient times.

Interesting points of aluminum and Li-ion, never heard about that before.
Did you do a test in an aluminium box? The lithium fire itself seem to have a lower melting temp then alu (was not aware of this) but the arcing and resulting lightbow of the stored energy can easily weld aluminium. How is then the metal structure of the aluminium after such a fire and the hull area nearby the battery housing.
For typical house loads with electric galley eg using tesla moduls i could imagine that works savely if usi g under 0.3C on alu boats as the c-rate the cells are used in charge and discharge is far below then in propulsion usage. Propulsion usage its still too dangerous in my opinion, especially the surges these motors can create.

I agree with some of your other points but the biggest risk for me are surprise box drop in with no external communication.
With lithium you need to know how or be able to know each cell or at least cell block (if parallel cells which i not recommend unless you are really experienced) is doing.
This at least for your main/master battery which should cover 1 day of average AH usage.
The rest to extend your capacity to your needs you can add proven surprice boxes with an independent last resort shut off like the BMV712 solution.

[seaexplorer]

I'll try to upload some photos tomorrow but zero impact on any aluminium outside the fire box. The paint on the other side of the aluminium directly exposed to large fire (10+kWh of energy) is not even bubbled. Plastic fittings right next to the firebox area are not melted or damaged.
Inside the firebox just lots of ash and a small gash in a stringer where there was an arc.
Zero impact on structure of 5mm aluminium plate.

[Fuss]

Originally Posted by s/v Jedi

Things are what they are. The forum doesn’t care about content providers, never really did and simply doesn’t deserve the content. Most who were like me are long gone and I now stay around for entertainment and to help others… but more and more I find that a lost cause as well because people only want to hear they did good even when they didn’t and are clueless

Where did the others go to??

[s/v Jedi]

Originally Posted by Fuss

Where did the others go to??

Some went to other fora like SailNet or Sailing Anarchy and many simply gave up posting useful content on fora.

[Fuss]

Originally Posted by Fuss

The forumite that learns the most and gets the most benefit is you Rivet. It enables you to gain knowledge and then go on to advise all the others and stop them being clueless. So the forums are really useful.

The dangerous problem is that some forum members comment on nearly everything electrical when they don’t really know what they are talking about. This is not obvious to the less electrically savvy members and this then temps them to take on this incorrect or incomplete or technically over complicated advice.
I see at the moment you are promoting lifepo4 without a lead acid starter and instead using lifepo4 to start the engine capt Rivet.
A subject you are not qualified to give advice on.

[CaptainRivet]

Originally Posted by Fuss

The dangerous problem is that some forum members comment on nearly everything electrical when they don’t really know what they are talking about. This is not obvious to the less electrically savvy members and this then temps them to take on this incorrect or incomplete or technically over complicated advice.
I see at the moment you are promoting lifepo4 without a lead acid starter and instead using lifepo4 to start the engine capt Rivet.
A subject you are not qualified to give advice on.

How are you to judge on that?
I am doing that since years, starting from the house as hybrid. And thats by the way a standard installation by nearly all french mass catamaran builders. One hull hybrid, the other classic starter. My Lavezzi was exactly setup like that in factory config and i kept it this way, just replaced lead with Lifepo4.
My system is checked and approved to be in line with ISO and insured like this.
Is that done on yous too? Will it pass 1st time?
My system can run 614A for 100min.
Can you run your system all on till LFP cuts off?
That proofs that i know how to do things right...and yes i do mistakes like all humans and i never stop learning.
And yes during stress testing i found issues on my system i openly documented here to and fixed them, thats what stress testing is for and needed!

2nd i started a decision(!) that with the current capability of lifepo4 the classic concept of dedicated starter and separate house is outdated and an additional !!! And better concept should be created with lifepo4 and defined with the mantra "engine must always start". That discussion is long overdue.

And my suggestion to that is hybrid starter/house and buffer battery concept (which should be a winston LFP or a starter LFP or LTO by can also be an AGM). You are welcome to make your statements and also propose a different concept.

[Wandering1]

Originally Posted by CaptainRivet

How are you to judge on that?
I am doing that since years, starting from the house as hybrid. And thats by the way a standard installation by nearly all french mass catamaran builders. One hull hybrid, the other classic starter. My Lavezzi was exactly setup like that in factory config and i kept it this way, just replaced lead with Lifepo4.
My system is checked and approved to be in line with ISO and insured like this.
Is that done on yous too? Will it pass 1st time?
My system can run 614A for 100min.
Can you run your system all on till LFP cuts off?
That proofs that i know how to do things right...and yes i do mistakes like all humans and i never stop learning.
And yes during stress testing i found issues on my system i openly documented here to and fixed them, thats what stress testing is for and needed!

2nd i started a decision(!) that with the current capability of lifepo4 the classic concept of dedicated starter and separate house is outdated and an additional !!! And better concept should be created with lifepo4 and defined with the mantra "engine must always start". That discussion is long overdue.

And my suggestion to that is hybrid starter/house and buffer battery concept (which can be lead but better LTO or a winston LFP or a starter LFP). You are welcome to make your statements and also propose a different concept.

Copied direct from the ISO
"In normal operation, different battery chemistries should not be connected in parallel or in series. Combining/automated charging relays should not be used between systems using different chemistries."

[CaptainRivet]

Originally Posted by Wandering1

Copied direct from the ISO
"In normal operation, different battery chemistries should not be connected in parallel or in series. Combining/automated charging relays should not be used between systems using different chemistries."

Yes i am aware of that. And thats why you cannot use VSR with a lead starter and LFP house, always said that and adviced to use argofet splitting diodes instead.

And where did i void ISO here?
Where does the concept of hybrid starter and buffer battery void that?

[Wandering1]

Originally Posted by CaptainRivet

Yes i am aware of that. And thats why you cannot use VSR with a lead starter and LFP house, always said that and adviced to use argofet splitting diodes instead.

And where did i void ISO here?
Where does the concept of hybrid starter and buffer battery void that?

You say you have mixed lead and LiFePo as a hybrid. Maybe you need to show your wiring or explain how you are a hybrid but don't mix chemistries

[Pete7]

Originally Posted by Wandering1

Copied direct from the ISO
"In normal operation, different battery chemistries should not be connected in parallel or in series. Combining/automated charging relays should not be used between systems using different chemistries."

I can do no better than copy this from another forum:

I think I should address the oft stated 'commandment' "Thou shalt no mix chemistries because to do so is an abomination"
In the past I have taken the stance that this is true except in the case of LiFePO4 and lead acid where the lithium sits within the profile of the lead acid quite happily and they live a loving symbiotic life together.

I have however now decided to approach it from a different perspective and argue that you are in fact not mixing chemistries. If you think about it, using the old definition, then when you charge your phone on the boat you are mixing chemistries because the lead acid boat battery is connected to the phone but it is via a charger and a BMS in the phone. Now look at the Lithium / Lead acid hybrid. You are connecting the lead acid to the lithium but not directly, one of the most fundamental things is that you do so via a BMS which does exactly what the BMS in your phone does and protects the battery.

In the case of the phone the input is 5v and it charges a battery to a max of 4.2v. In a boat system you don't need the actual 12v-5v converter because the lithium charge requirements sit within those of the lead acid. This gives another layer of safety to the system because a BMS failure will not expose the lithium to any excess / dangerous voltage. Ironically if the phone BMS dies then the phone battery can explode and if the 12-5v converter fails it can fry the phone and the phone uses a flammable battery technology.
Maybe that is a better way of looking at that commandment and saying that it actually doesn't apply!

Acknowledgement: Phil Brooke-Little