Tesla Lithium battery question.

[DeepFrz]

Originally Posted by a64pilot

I think that is common for all traction battery banks, I know it is for Prius, you can if you listen for it, hear the fan kick in, although I think interior temp of the car also has a lot to do with it, I bet in Phoenix in August, the fan comes on with the car booting up.

I'm sure you are right. I guess they must chill the coolant on the 110 deg. days and heat it on the days where temps. drop below freezing.

[a64pilot]

Inside of a car will exceed I think 150 F pretty easily.
I remember one vacation the Army sent me on, we put “temp a dot” temp strips on all the electronic boxes in an Apache Helicopter. Every single one turned the highest temp “dot” Black at 200F and none were in the sun, inside of “FABS” or forward avionics bays.
They had air conditioned air blown through them, the heat came from bing heat soaked in the sun.
We had an ECS light (Environmental control system) that come on at I think 105F and of course procedures to follow when it did, which systems to shut down etc.
Well on that vacation, even at night the light usually never went out

Sun heating on dark metal can get something phenomenally hot.

If they can live in Kuwait or Saudi in a summer or even Phoenix, they can easily survive a boats heat.

Because of the excess heat from that vacation, the newer Apache has dual 7.25 ton airconditioners.
I think that is 174,000 BTU of airconditioners

[DeepFrz]

I had to post this link to a video of a guy with a really hot Tesla battery powered ski boat. He purposely drove a battery module to thermal and power overload to see what would happen. He then completely dismantled the module and cut several 18650 cells in half. Very interesting results of this testing.

https://www.youtube.com/watch?v=mWjG3REOF-M

[getyourbone]

Not Tesla but I had 48v Chevy volt modules on the boat...worked great!

700 watts of solar connected through a controller that bumped the voltage from about 37 volts from panels up to charge the batteries to a max of 50.5 volts. From the batteries I used a buck or drop down converter to run 12v and 24v. Between the the controller keeping the batteries below max and the converter cutting out if voltage dropped below a certain threshold, the batteries were protected.

The talk about cooling is kind of a mute point if you are talking about basic usage...electronics, lights, refrigeration, small appliances.

[GrowleyMonster]

Originally Posted by boat_alexandra

You keep repeating this, but it is not an important factor after all.

It would be so easy to safely install Li-ion batteries simply by distributing the cells throughout the boat or in a way with sufficient distance between them to prevent thermal runaway.

So how far apart... an inch, maybe? Or more? To equal my present propulsion bank would require lets see... 1ah real world capacity per cell, 13 cells in series for 48v, 220x13=2860 cells each taking up about what... 6 cubic inches... I think I need a bigger boat. No, a BMS, a reliable one with system redundancy, as well as active cooling, are needed to match the safety of my golf cart batteries in any reasonable amount of space. When you build it and operate it for a few years and prove otherwise, I will certainly be interested and possibly won over.

[Dockhead]

Originally Posted by a64pilot

Prius packs just due to how many there are were the least expensive and most available.
The Nimh packs are safer

I briefly considered it, but again, why? what do you gain?

Many things are possible, just don't make sense compared to what is already in use, like wind turbine driven boats. You can do it, it will work, but why?

Also, considering how cheap brand new quality warrantied LiFePo4 prismatic cells are -- why would you mess around with a used battery pack with doubtfully appropriate chemistry and unknown condition and quality?

[DeepFrz]

Dockhead, how much does a 12 volt LFP battery cost in your local? I see "Battle Born" advertised at around $950. US for 100 ah 12 volt, so probably close to $6,000. for a complete 400 ah system. That doesn't sound cheap to me. Maybe you can do better?

[travellerw]

Originally Posted by DeepFrz

Dockhead, how much does a 12 volt LFP battery cost in your local? I see "Battle Born" advertised at around $950. US for 100 ah 12 volt, so probably close to $6,000. for a complete 400 ah system. That doesn't sound cheap to me. Maybe you can do better?

Notice he posted "prismatic cells".. So basically a DIY build..

My 400Ah of CALB cells with shipping, BMS and all the hardware was just shy of $3000. Based on the cost post a few days ago, that would be pretty average for a prismatic cells build.

[newhaul]

Originally Posted by DeepFrz

Dockhead, how much does a 12 volt LFP battery cost in your local? I see "Battle Born" advertised at around $950. US for 100 ah 12 volt, so probably close to $6,000. for a complete 400 ah system. That doesn't sound cheap to me. Maybe you can do better?

ok how does a basically drop in battery compare to those if, diy build of Lfp cells or diy build of cells from an ev car.

[a64pilot]

As far as money. I go with Maine Sails numbers. $2700 US for a 400 AH bank.
Cheapest you can get lead, and it’s pretty good lead is about $600 US for a 600 AH lead, larger size is need to get about the same usable AH from both.
So it’s a little more than 400% price difference.

Now as has been said over and over, for some reason lead is WAY more expensive in other countries, and LFP, way less expensive than in the US, so it’s a completely different metric.
I don’t know why, it would be interesting to find out why, has to be taxes of some form or other.

In particular, why are Lifelines so horribly overpriced?

[newhaul]

Originally Posted by a64pilot

As far as money. I go with Maine Sails numbers. $2700 US for a 400 AH bank.
Cheapest you can get lead, and it’s pretty good lead is about $600 US for a 600 AH lead, larger size is need to get about the same usable AH from both.

Now as has been said over and over, for some reason lead is WAY more expensive in other countries, and LFP, way less expensive than in the US, so it’s a completely different metric.
I don’t know why, it would be interesting to find out why, has to be taxes of some form or other.

In particular, why are Lifelines so horribly overpriced?

I think its just the seller markup that the NA market will support.

[a64pilot]

Originally Posted by newhaul

I think its just the seller markup that the NA market will support.

And the lead in Europe?
Doesn’t make sense that in Europe they accept a huge mark up on lead, but won’t on LFP.

Although when I was in Germany, the old Mercedes I bought needed a new battery. I priced one and decided to park on the hill instead
Battery cost was likely 1/4 of what I paid for the car.
So lead battery cost has been high there for awhile, I wonder why?

[john61ct]

Originally Posted by travellerw

Notice he posted "prismatic cells".. So basically a DIY build.

The packaged systems are also based on prismatics.

Just means avoid DIY based on cylindricals or pouches.

[john61ct]

Originally Posted by a64pilot

As far as money. I go with Maine Sails numbers. $2700 US for a 400 AH bank.

That was a while ago, and above average access to known-good vendor channels.

You and I can't get that price today.

> lead is WAY more expensive in other countries, and LFP, way less expensive than in the US, so it’s a completely different metric. I don’t know why, it would be interesting to find out why, has to be taxes of some form or other.

Yes taxes made lead lots pricier.

Therefore LFP became lots more competitive much earlier. Distribution channels developed, service & support infrastructure is there we can only dream of in the US.

Greater penetration of alternative (non FF) energy as well

And perhaps as with the much larger land/mobile camping market, Euro / Aussie / NZ consumers just have more "disposable" spending money,

since solid healthcare, childcare, tertiary education, secure affordable housing and old age security are more built into the social infrastructure rather than only enjoyed by the top %s.

> In particular, why are Lifelines so horribly overpriced

Shipping costs are crazy for lead, and also a top notch "exotic" overseas brand will command a large premium.

I'm sure Full River are cheaper there?

[john61ct]

Rather than saying "why is lead so damn crazy expensive in the rest of the world"

Ask "why is it so crazy cheap in the US"?

Not just low VAT, but also regulatory costs.

The US tends to avoid building in the inherent externalities into commodity costs

environmental issues especially