Lithium battery C-rate question

[jonase]

I had a quick look at the Oceanvolt website (with focus on quick). Looks like they are integrating the Super-B batteries using CAN with some controller that might also feed data from the engine. If you go with a different battery than Super-B the CAN communication might be something that is required.

You most likely already know this...

https://youtu.be/sgQ9RV_5HQU

[newhaul]

Originally Posted by yvest

Did you look into the Torqeedo batteries ?
https://www.torqeedo.com/us/en-us/pr...-/2104-00.html

Not LFP (BMW EV technology), must also more energy density, and already used on quite a few sailboats.

lithium cobalt is a good chemistry if well managed . Even the slightest overcharge can cause it to burn. And we all know the worst thing on a boat is a fire . So definitely if using these you need all of the ancillary equipment from torqeedo for management of these cells for protection of them as well as protect you and your boat.

[Jatar]

Originally Posted by newhaul

lithium cobalt is a good chemistry if well managed . Even the slightest overcharge can cause it to burn. And we all know the worst thing on a boat is a fire . So definitely if using these you need all of the ancillary equipment from torqeedo for management of these cells for protection of them as well as protect you and your boat.

Yes, I am also considering these. I need to learn more about the safety side, and the price is fairly steep. However, the weight aspect is very attractive, coming in well below all the other batteries I am considering, at around 200 pounds less.

[newhaul]

Originally Posted by Jatar

Yes, I am also considering these. I need to learn more about the safety side, and the price is fairly steep. However, the weight aspect is very attractive, coming in well below all the other batteries I am considering, at around 200 pounds less.

as a propulsion bank yes as a house bank no.
JMO

[yvest]

Originally Posted by newhaul

as a propulsion bank yes as a house bank no.
JMO

Why ?

[newhaul]

Originally Posted by yvest

Why ?

there have been to many fires reported on commercial aircraft running the same lithium cobalt formula batteries.
A slight overcharge and you have a fire.
In the navy I was a firefighter. I lost friends to that beast and almost lost mine several times as well. But as I said it is just my personal opinion.

That is aside from the cost of the system . With the cost of all the ancillary bite I can add a couple hundred more ah of Lfp .

[Jatar]

Originally Posted by newhaul

there have been to many fires reported on commercial aircraft running the same lithium cobalt formula batteries.
A slight overcharge and you have a fire.
In the navy I was a firefighter. I lost friends to that beast and almost lost mine several times as well. But as I said it is just my personal opinion.

That is aside from the cost of the system . With the cost of all the ancillary bite I can add a couple hundred more ah of Lfp .

Yet that doesn't explain why you would accept them as a propulsion bank. It sounds more like you would recommend against them altogether.

[newhaul]

Originally Posted by Jatar

Yet that doesn't explain why you would accept them as a propulsion bank. It sounds more like you would recommend against them altogether.

go ahead and use them its your boat your money your life your choice .

[Jatar]

Originally Posted by newhaul

go ahead and use them its your boat your money your life your choice .

I think you missed my point. I have not decided to use them. I just wanted to understand your comment about them being OK to use as a propulsion bank, but not as a House bank.

[newhaul]

Originally Posted by Jatar

I think you missed my point. I have not decided to use them. I just wanted to understand your comment about them being OK to use as a propulsion bank, but not as a House bank.

I did not miss that however you did seem to miss the part you didn't quote that said if you also have all of the ancillary equipment that torqeedo sells that supports and charges the bank.

Seems to not be compatible with pure off grid operation. Charging off of alternative / renewable sources.
Again just my observations and personal opinions

[Jatar]

Originally Posted by newhaul

I did not miss that however you did seem to miss the part you didn't quote that said if you also have all of the ancillary equipment that torqeedo sells that supports and charges the bank.

Seems to not be compatible with pure off grid operation. Charging off of alternative / renewable sources.
Again just my observations and personal opinions

Sorry, I appreciate your comments and views.

[Jatar]

I'm not sure what ancillary equipment you are referring to, though. Here is what is included in their battery (quoting from their site):

"Including battery management system with integrated protection against overcharging, short circuit, deep discharge, polarity reversal, overheating and submersion."

[newhaul]

Originally Posted by Jatar

Sorry, I appreciate your comments and views.

not an issue I was rather vague in my initial post having gotten much sleep in the last 2 weeks dad broke his pelvis so I'm not on the boat and not thinking clearly .
Thanks for making me think .

[newhaul]

Originally Posted by Jatar

I'm not sure what ancillary equipment you are referring to, though. Here is what is included in their battery (quoting from their site):

"Including battery management system with integrated protection against overcharging, short circuit, deep discharge, polarity reversal, overheating and submersion."

I am referring to their specific compatibility 13 amp charger that carries a $900 price tag .
And requires shore power https://www.torqeedo.com/us/en-us/pr...0/2213-00.html

Or the $2200 50 amp fast charger . https://www.torqeedo.com/us/en-us/pr...0/2212-00.html

[john61ct]

LFP would be a fantastic choice for propulsion as well as House use, power density is excellent, lifespan 5-10x longer than other LI chemistries, and **most** importantly for a boat, much safer, little risk of thermal runaway.

Other LI chemistries are favored by EV developers due to higher energy density and much lower cost per kWh - for them, not necessarily to the end user. Much larger banks, the difference can really add up.

Professionally engineered and installed systems for super-expensive EP "science experiments" (not very practical IMO, for my use cases anyway)

will have much more sophisticated safety features, TMS (thermal management systems, active cooling / warming) as well as more robust BMS,

than what you usually find with House systems.

All the above is why the (mostly) consensus is:

LFP is the **only** LI chemistry for House use.

I would be even stronger about this wrt DIY setups.

People messing around with hundreds of little cylindricals or repurposed EV packs removed from their engineered protective systems should do so out in the back shed.