100AH lithium battery holds MORE power than 100AH lead acid??

[CaptainRivet]

Originally Posted by Simi 60

The bit you're not getting is that electric vehicle batteries that catch on fire are a different chemistry to Lifepo4 used in boat house banks

Not only that, a tesla is charged with up to 600V and the cells need to be watercooled to handle that extreme use. So the different I-ion found in vehicles are used to their limits of 2 till 3C

A Lifepo4 house bank is a different chemistry and you literally padding the lifepo4 in a typical haouse bank use you are below 0.3C. Thats far below what even a budget low quality cell is able to deliver.

[CaptainRivet]

Originally Posted by rwidman

That my battery charger has no "lithium" setting, my alternator has no settings or adjustments at all and that when charging, any lithium batteries would be in parallel with the AGM starting battery.

Simply get a BMS like electrodacus that steers yor charge sources and simply shuts them off when battery is full, no lithium setting is needed.
For the alternator get a DC2Dc charger with 40% of your alternators rating and put it between AGM starter and Lifepo4 house and job is done.

[s/v Jedi]

I think y’all should keep it at the Walmart special no-maintenance all purpose batteries

[kmacdonald]

Originally Posted by s/v Jedi

I think y’all should keep it at the Walmart special no-maintenance all purpose batteries

Yep, if you have to ask how to implement lithium, don't do it.

[Fuss]

Originally Posted by s/v Jedi

I think y’all should keep it at the Walmart special no-maintenance all purpose batteries

One of the posters above was planning on putting Tesla batteries in his boat at one stage and then gives other forum members advice!!.

[Baronkrak]

Originally Posted by rwidman

That my battery charger has no "lithium" setting, my alternator has no settings or adjustments at all and that when charging, any lithium batteries would be in parallel with the AGM starting battery.

Buy a Victron blue smart charger.
https://www.victronenergy.com/charge...t-ip65-charger

At what voltage your alternator charges the AGM?

[rwidman]

Originally Posted by Baronkrak

Buy a Victron blue smart charger.
https://www.victronenergy.com/charge...t-ip65-charger

At what voltage your alternator charges the AGM?

The engine's alternator is designed for flooded cell or AGM batteries. It is from 1999, well before lithium batteries were available.

Someone on another forum suggested what seems like a good solution; a DC to DC charger. This connects from the AGM starting battery to the lithium house bank. The alternator or battery charger delivers the appropriate voltage to the AGM starting battery and the DC to DC charger uses the house battery to charge the lithium bank.

I haven't priced the DC to DC charger yet though.

[sailorboy1]

Originally Posted by CaptainRivet

Simply get a BMS like electrodacus that steers yor charge sources and simply shuts them off when battery is full, no lithium setting is needed.

I HATE that answer. It is like saying "don't worry about it, the fuse will blow".

BMS should never shutdown a battery as you charge sources should be set properly. If you have something that you can not adjust, well you need to change that. But really now, how many boats have any need for LFP if their system is so outdated that they can change programming? My boat is 22 years old and it has charge sources that are still in use.

[sailorboy1]

Originally Posted by CrispyCringle

There are differences in battery quality. Look up Will Prowse on YouTube. Pretty knowledgeable guy on batteries, and has reviews of various batteries. There are only a few manufacturers of the actual cells. Those cells are graded for quality. BMS systems vary in quality and capability. Battery manufacturers simply assemble the cell into a case and put either a proprietary, or purchased BMS on it. And lastly, some of the cheapies literally have rocks or wood spacers inside the battery case.

If you have basic knowledge of DC electrics, to build your own battery packs is vastly cheaper than purchasing retail. The knowledge is out there. Not hard.

I watched the Wll Powers tear downs and got 4 $300/100ah Power Queens. I didn't see any with rocks or wood spacers inside, but so what if they do?

[sailingharry]

Originally Posted by wholybee

So, part of the issue with this argument is that LFP "don't catch fire", but that isn't an absolute, literal "don't." They can. They have. Just like lead-acid batteries have exploded in a ball of fire. It _can_ happen, but in the common sense of the word, it doesn't happen very often, so we say it doesn't happen.



When an LFP does catch fire, it often self-extinguishes before any real damage is done, or is easy to put out. There are far more installations in RVs, and if you look there you can see examples. I have seen no examples on boats-yet, but at this point most boat installs are well done, RV's are more commonly installed by backyard garage mechanics. Almost always the 280Ah/300Ah EVE/CATL/Liitokala form factor bought from Alixxx. This is why I recommended both against Alixxx and to buy Winston or Calb cells.

Okay, you kind of ruined my breakfast. Like you pissed in my Cheerios. I mean, I was convinced LFP was very high on the safety index.
I did read every post in all of those links.
The first one was exceptionally unsettling. The victim was completely clueless, which made it a little bit difficult to follow. I'm not criticizing him, not everyone is as smart as the people on this forum. But he has had his system a year, it was installed by the PO, and he doesn't even know how his basic parts are wired. All that said, it does sound like the cell might have somehow been the source. Like I said, unsettling.
The others appeared to be straight up electrical fires. Shorts that lead to things catching on fire. A year or so ago, the 2/0 cable off my 140A alternator had a high resistance connection to the fuse. Melted the insulation off the cable, charred the housing of the fuse, but never opened the fuse. Scary, could have led to a fire. But a question, is that a condemnation of alternators, or AGM batteries? Or does it simply prove that high power sources can cause electrical fires. It's analogous to the posts you referenced where external shorts led to external stuff catching on fire. Not LFP batteries spontaneously combusting or even burning when under heavy loads.
I'm not trying to be argumentative, I truly appreciate those links. I'm trying to understand what I learned from reading those links. And remain open to the idea that we don't know everything.

[sailingharry]

Originally Posted by rwidman

OK, shopping for 12 volt 100 ah lithium batteries, I see them from $200 to over $1,000 with the same specifications.

My life experience tells me that there is probably a difference, but I can't tell from the advertising or specifications.

And while it is generally true that quality does cost more it absolutely does not follow that more expensive is higher quality. Sometimes more expensive is just more expensive. Mercedes-Benz has well documented (but still anecdotal) reliability well below Toyota, but at a much higher price. So as you point out, how do you decide which drop-in to buy? LOL

[sailingharry]

Originally Posted by sailorboy1

I HATE that answer. It is like saying "don't worry about it, the fuse will blow".



BMS should never shutdown a battery as you charge sources should be set properly. If you have something that you can not adjust, well you need to change that. But really now, how many boats have any need for LFP if their system is so outdated that they can change programming? My boat is 22 years old and it has charge sources that are still in use.

Actually, SB, I disagree with the response in this case. The BMS shutting off a charge source is legitimate control. It is not the BMS shutting off the battery, which is insane.

I will likely use an Electrodocus when I go lithium. Most of my charge sources are programmable. Still, the Electrodocus will control them as well.

The first issue I have is two of my charge sources are not programmable, nor even remotely controllable, and so they will be controlled through a contactor. I have an ancient multi-voltage Victron Centaur charger that was installed by the PO for a trip overseas and remains there for such a potential journey. I also have a Watt&Sea towed generator. I also used to have a wind generator, which also is not programmable. Having the Electrodocus disconnect these is no different than having them disconnect themselves if they were smart enough. This is not some sort of a cascading failure event, or an emergency backup. It is managing the charge sources.

But even more, the Electrodocus is smarter than any of the external charge sources. It will not only shut them down on pack voltage, but will disconnect them on any individual cell over voltage. So even though my inverter, alternator regulators, and solar controllers will all be configured to a safe voltage, they will also all be controlled and shut down by the BMS on a high cell voltage.

[sailorboy1]

Maybe instead upgrade your controller to something for the 2000s and is programmable.

I change mine based on didn't operations.

I still disagree with the BMS ever causing an action. You shouldn't have ever gotten into that condition. If you want to use something like that (if your system has it) as a backup that is fine. But to me that is like having a 15A breaker feeding through a 20A fuse in case the breaker doesn't trip.

[rslifkin]

Originally Posted by sailorboy1

Maybe instead upgrade your controller to something for the 2000s and is programmable.

I change mine based on didn't operations.

I still disagree with the BMS ever causing an action. You shouldn't have ever gotten into that condition. If you want to use something like that (if your system has it) as a backup that is fine. But to me that is like having a 15A breaker feeding through a 20A fuse in case the breaker doesn't rip.

From my understanding, the Electrodacus is meant to be able to control individual charge sources vs just cutting off all charge or discharge (or everything in one shot). Ideally charge sources should stay within its limits, but if you have a charge source that can't be told to stop at the right time, it gives you the ability to cut off just that charge source when conditions require.

[s/v Jedi]

The BMS should never cut off a charge source because the charge source should stop charging well before the BMS would do anything about it.

Only during disasters, like a battery with failing cells, should it be necessary for the BMS to take any such action. For “normal” out of balance cell issues, the BMS may enable a balancer: again this has nothing to do with cutting off chargers.