Lithium battery C-rate question

[john61ct]

Yes and Victron's also got a non-LFP lithium bank, NMC I believe

[Delfin]

Originally Posted by newhaul

that is if you ever actually buy any Lfp or any other Lipo for that matter to actually get real world experience with .

My insurance doesn't care what batteries I have onboard.

Yes, I was looking for the battery exclusion section to my policy, and it seems to be missing. It also seems to be silent on which anchor I use. Yet John sounds so, well, authoritative that he must have such exclusions on his yacht policy. If he had a boat, I mean.

[newhaul]

Originally Posted by Delfin

Yes, I was looking for the battery exclusion section to my policy, and it seems to be missing. It also seems to be silent on which anchor I use. Yet John sounds so, well, authoritative that he must have such exclusions on his yacht policy. If he had a boat, I mean.

I called my agent he said that the policy doesn't say anything about batteries. they just want to know what fuel for the main engine . They don't even care what I cook with
As to anchor he said appropriate for my vessel

[Q Xopa]

Originally Posted by john61ct

Yes and Victron's also got a non-LFP lithium bank, NMC I believe

Yes that non LFP Victron batts. Not for House banks by your rules.

[john61ct]

No, I just can't imagine what advantages would overcome higher risk and the huge added cost of needing an experienced pro to design and install the system.

[newhaul]

Originally Posted by john61ct

No, I just can't imagine what advantages would overcome higher risk and the huge added cost of needing an experienced pro to design and install the system.

well when you finally get a bank let us know .

[bleuet323]

Originally Posted by john61ct

Yes and Victron's also got a non-LFP lithium bank, NMC I believe

If we all remember the lithium batteries on planes. They do not like to be charged quickly or discharged quickly. Any sealed battery is not great for high rate discharge or charge. What they are great for is to be charged and able to keep that charge for a long time without losing very much of its charge like a wet battery. To provide high amperage you would need many in parallel taking in account the amperage spec of the battery you have. Charging them slowly is always the better option.

[witzgall]

Blue323,

Please not another mention of the plane batteries. Different chemistry than what is being talked about here.

The safe charge and discharge rate of a battery depends on the chemistry and construction. Generalizations about not liking to be charged or discharged fast, well, you know what they say about generalizations.

It seems you are new here, please read and learn before making blanket statements. Otherwise, welcome to the forum!

Chris

Originally Posted by bleuet323

If we all remember the lithium batteries on planes. They do not like to be charged quickly or discharged quickly. Any sealed battery is not great for high rate discharge or charge. What they are great for is to be charged and able to keep that charge for a long time without losing very much of its charge like a wet battery. To provide high amperage you would need many in parallel taking in account the amperage spec of the battery you have. Charging them slowly is always the better option.

[newhaul]

Originally Posted by bleuet323

If we all remember the lithium batteries on planes. They do not like to be charged quickly or discharged quickly. Any sealed battery is not great for high rate discharge or charge. What they are great for is to be charged and able to keep that charge for a long time without losing very much of its charge like a wet battery. To provide high amperage you would need many in parallel taking in account the amperage spec of the battery you have. Charging them slowly is always the better option.

they are lithium cobalt oxide Not lithium iron phosphate. (Lfp)
we use Lfp batteries in our boats ( lowest fire risk of any of the cemeteries )

[Retirecaribbean]

All,
Biggest issue with Lithium is with the risk of fire and the following link is a company that has been able to overcome that issue with monitoring.

They primarily service the Telecom market, but understand that this market has one of the most stringent standards for DC power as the entire network runs on DC power.



https://www.incellint.com/smart-lithium-battery/
scott.erwin@incellint.com

[Stu Jackson]

Originally Posted by Montanan

My apologizes, no offense intended, I wasn't stating that your system will be a DIY setup. I am just cautioning that it be done right as far too many battery systems are not properly designed on boats because electrification on recreational boats, e.g., sailboats is comparatively new as to having large house battery banks. Some production boats direct from the factory are not properly optimized as to their battery configurations, the industry is still adapting.>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

That's an interesting observation.

I agree that "Some production boats direct from the factory are not properly optimized as to their battery configurations..." since many new boats still come with two equal house banks, unfortunately D types that aren't true deep cycle.

But it seems that "..electrification on recreational boats, e.g., sailboats is comparatively new as to having large house battery banks" may be unusual, with stress on the comparatively new as to having large house battery banks."

Nigel Calder wrote about the advantages of having the largest house bank over 20 years ago in the 2nd edition of his popular Boatowners Manual for Mechanical and Electrical Systems.

Of course, "comparatively new" could be compared to the either the beginning of boating (!), the beginning of time itself, or to having electrical systems on recreational boats, say in the 1930s. IIRC, even the Titanic had electricity.

OTOH, since the concept is well over 20 years old now, should it still be considered "new?"
Just pickin' nits here...

[geoffa]

There is a big step between SWAG scientific wild arse guess and sound systems engineering. It is always sensible to understand what domain you are operating in.
Geoff
FIEAUST, CPEng, NER, MCEE

[Dockhead]

As far as I can tell, those batteries, cost more than $3000 each in the U.S. -- https://www.batterypete.com/big-batt...-sb12v160e-zc/. So you're talking about $36,000 of batteries?


Most people trying to do a system like this, like everyone actually, would buy the raw cells at $1.20 per a/h at 3.2v, or whatever -- so $9000 or so for the cells, plus something for a proper BMS which remains and can be used with replacement cells should that be necessary.



Is there any particular reason why you want the batteries to be pre-packaged into lead-like units of 12v nominal at three times the cost? Lithium is very different from lead and needs a different kind of infrastructure. Trying to imitate lead form-factors and package the infrastructure into the same box with the cells seems like an inefficient approach to me. Especially if you're doing it for electric propulsion so you don't have any existing lead infrastructure you are trying to reuse.

[newhaul]

Originally Posted by Dockhead

As far as I can tell, those batteries, cost more than $3000 each in the U.S. -- https://www.batterypete.com/big-batt...-sb12v160e-zc/. So you're talking about $36,000 of batteries?


Most people trying to do a system like this, like everyone actually, would buy the raw cells at $1.20 per a/h at 3.2v, or whatever -- so $9000 or so for the cells, plus something for a proper BMS which remains and can be used with replacement cells should that be necessary.



Is there any particular reason why you want the batteries to be pre-packaged into lead-like units of 12v nominal at three times the cost? Lithium is very different from lead and needs a different kind of infrastructure. Trying to imitate lead form-factors and package the infrastructure into the same box with the cells seems like an inefficient approach to me. Especially if you're doing it for electric propulsion so you don't have any existing lead infrastructure you are trying to reuse.

here is a manufacturer that I can get the bare cells thru cheap ( no I hadn't researched the company yet ) . 115 per unit 3.2v 200ah cells.

Its just an example of what's available at a much cheaper cost.

[Dockhead]

Originally Posted by newhaul

here is a manufacturer that I can get the bare cells thru cheap ( no I hadn't researched the company yet ) . 115 per unit 3.2v 200ah cells.

Its just an example of what's available at a much cheaper cost.

In Europe, a lot of folks use these guys:


https://www.ev-power.eu/Winston-40Ah-200Ah/

A serious company with real support, selling the major brands: Winston, CALB, Sinopoly, and not mystery no-name cells buried in some box. Roughly $400 U.S. per kW/h for the cells.


I think it's dangerous wishful thinking, to believe that just because it looks like a lead battery, that you can just hook it up and use it like one. I think one had better start with a clean sheet of paper, especially that paper which is in one's own mind.