My New Favorite Battery.

[Sunking]

Old men tend to miss the sea change. I have a few friends who were old men by age 35.

I used to participate in a camera forum where the old engineers insisted that a full frame digital 35mm camera could never be produced economically. It was fundamentally impossible. After Contax introduced the first reasonably priced full frame digital 35mm camera, they still argued it was impossible.

It deja vu all over again.

I am one of the most tech savy person you will ever meet. In my profession you have to be ahead of the technology as it is required to stay current and maintain a PE licensure in Electrical and Computer: Power. Do you have a PE in any of the 25 disciplines? I did not think so.

I am telling you right now Lithium batteries are not ready for home use yet for Joe Home Owner. To go one step further they are not ready for EV's yet either. Not even half way there yet. To be practical in a EV a battery needs to have:

• Specific Energy Density of 400 wh/Kg to make a usable sized car with a range competitive with ICE. Today only 200 wh/Kg with Lithium Cobalt.
• 4C charge rate and 10C discharge rate. Some lithium have that, but not one you can use in a EV as Polymer has only 150 to 200 cycles in them and cost $3/wh or $3K per Kwh.
• 2000 cycles without any meaningful capacity loss to 90% DOD. None exist
• Thermal performance to at least 0 degree F. None exist. Best lithium out there today only have 50% capacity at 0 degrees F, and heat destroys a lithium battery in short time. Lithium batteries have a very narrow temperature operating range which is why Telsa has to use liquid heating and cooling in all their cars.

[tech01x]

Tesla's batteries

I am one of the most tech savy person you will ever meet. In my profession you have to be ahead of the technology as it is required to stay current and maintain a PE licensure in Electrical and Computer: Power. Do you have a PE in any of the 25 disciplines? I did not think so.

I am telling you right now Lithium batteries are not ready for home use yet for Joe Home Owner. To go one step further they are not ready for EV's yet either. Not even half way there yet. To be practical in a EV a battery needs to have:

• Specific Energy Density of 400 wh/Kg to make a usable sized car with a range competitive with ICE. Today only 200 wh/Kg with Lithium Cobalt.
• 4C charge rate and 10C discharge rate. Some lithium have that, but not one you can use in a EV as Polymer has only 150 to 200 cycles in them and cost $3/wh or $3K per Kwh.
• 2000 cycles without any meaningful capacity loss to 90% DOD. None exist
• Thermal performance to at least 0 degree F. None exist. Best lithium out there today only have 50% capacity at 0 degrees F, and heat destroys a lithium battery in short time. Lithium batteries have a very narrow temperature operating range which is why Telsa has to use liquid heating and cooling in all their cars.

I've done a lot of research into the cells that Tesla uses for their car. They might or might not be the same that go into the Powerwall product, but if they are:

1) Tesla is using nickel aluminum cobalt (NCA) with a graphite anode. The original Roadster used lithium cobalt.
2) The current specific energy of Tesla's NCA cells in the Model S is around 260 Wh/kg, but that is irrelevant for stationary storage
3) The closest Panasonic retail cell to Tesla's Model S cell is the NCR18650BE, which can't have that high of charge rate or discharge rate. Pulses to 10C, but realistically Tesla uses 4-5C discharge and max charging at 1.7C. But stationary storage doesn't really need it either, as you likely inverter limited.
4) Panasonic has tested the same base chemistry with > 90% capacity out to 3,000 charge cycles: http://ma.ecsdl.org/content/MA2011-0....full.pdf+html
This was a while ago and reportedly Tesla's custom iteration is better. The degradation data coming from cars with > 100,000 miles of them bear this out. They achieve this by limiting the depth of discharge to 91%, avoiding both the very top and very bottom SoC.
5) Cost for the raw cells is reportedly somewhere between $160/kWh and $200/kWh. There was an SAE report with $160/kWh. These cells have to be integrated into bricks with external protection.
6) Narrow temperature performance, yes, but you have to quantify that. Operating temperature of the pack is -20 degrees C to 43 degrees C. Panasonic's NCA chemistry and electrolyte actually does quite well with very high temps. With low temps, it is best not to charge them with a lot of current under 0 degrees C, but that's why they are thermally managed.

[russ]

Old men tend to miss the sea change. I have a few friends who were old men by age 35.

I used to participate in a camera forum where the old engineers insisted that a full frame digital 35mm camera could never be produced economically. It was fundamentally impossible. After Contax introduced the first reasonably priced full frame digital 35mm camera, they still argued it was impossible.

It deja vu all over again.

Donald - You are a bit of an ass at a young age apparently.

Anyone writing "deja vu all over again" doesn't even understand what the phrase means.

[Samsolar]

I am telling you right now Lithium batteries are not ready for home use yet for Joe Home Owner. To go one step further they are not ready for EV's yet either. Not even half way there yet. To be practical in a EV a battery needs to have:

So if Lithium batteries aren't ready yet then how did Nissan sell 158,000 Leafs? Perhaps by ready you mean ready to replace all fossil fuel vehicles?

It would seem that Nissan (or Tesla) has built a product that is selling well with a battery that doesn't meet the criteria you listed but is working quite well for thousands of people. I guess it is lucky for Nissan and their shareholders that many buyers look at things differently than you do.

[russ]

So if Lithium batteries aren't ready yet then how did Nissan sell 158,000 Leafs? Perhaps by ready you mean ready to replace all fossil fuel vehicles?

It would seem that Nissan (or Tesla) has built a product that is selling well with a battery that doesn't meet the criteria you listed but is working quite well for thousands of people. I guess it is lucky for Nissan and their shareholders that many buyers look at things differently than you do.

Sam - If you can't understand the difference between an automotive or aviation application and home use you are a lost cause.

Everyone is waiting for the next battery - maybe this is it and maybe not. A year or two and we will have a far better idea about this.

Musk needs something good to happen right now - other things have been a bit on the sour side.

[Sunking]

So if Lithium batteries aren't ready yet then how did Nissan sell 158,000 Leafs? Perhaps by ready you mean ready to replace all fossil fuel vehicles?

I mean mainstream vehicles. Most all Leaf and Tesla owners have second ICE car. Today's lithium battery cannot replace an ICE car. EV is a second car for folks who have that kind of money to spend to feel good about themselves. To get there 300+ mile range, 15 minute recharge, 10 year battery life, and competitive priced. No where close to that yet.

FWIW Nissan Leaf battery has been plagued with problems, first 3 model years all need replacements. Which is why Nissan has offered replacements for $5000 plus labor.

[Samsolar]

Sam - If you can't understand the difference between an automotive or aviation application and home use you are a lost cause.

I can Russ. I'm also fairly good at reading what others have posted before I respond....

If you were reading the messages in the thread you would see that Sunking stated the Lithium batteries weren't ready for EVs. I just pointed out hundreds of thousands of EVs have been sold with supposedly "not ready batteries". As with all things, the market will decide but the trend seems fairly obvious..

[Sunking]

3) The closest Panasonic retail cell to Tesla's Model S cell is the NCR18650BE, which can't have that high of charge rate or discharge rate. Pulses to 10C, but realistically Tesla uses 4-5C discharge and max charging at 1.7C. But stationary storage doesn't really need it either, as you likely inverter limited..

I agree and no reason to pay the premium price for that. There are longer lived cells at much lower cost in both FLA and LiFeP04 which are much more forgiving. FWIW I have a NEV with Lithium batteries. Built it myself, my second build. I use LiFeP04

[tech01x]

I agree and no reason to pay the premium price for that. There are longer lived cells at much lower cost in both FLA and LiFeP04 which are much more forgiving. FWIW I have a NEV with Lithium batteries. Built it myself, my second build. I use LiFeP04

Lithium titanate might be longer living - it isn't clear that LiFePO4 would be longer living. But the clear issue is total ROI, which means both cycle life and acquisition cost. Lithium titanate is still very expensive, much higher than LiFePO4. While most of us can't source Tesla/Panasonic cells at $160/kWh, Tesla can do that since they bought about 2.5 GWh of cells last year. As a result, there is no premium. Tesla/Panasonic cells are simultaneously the highest specific energy and the lowest cost per kWh of the major high power, high current lithium ion products. Now, Tesla throws in a DC charge controller, packaging, liquid thermal management, and gross margin to get to $429/kWh (usable).

As the Gigafactory comes online, the cell prices drop further.

BTW, the head of Tesla's battery efforts used to work for Panasonic, both in manufacturing in Japan and heading up Panasonic's U.S. research lab. The cells are made by Panasonic to Tesla's spec, so they aren't exactly what you get in retail. The other problem with sourcing Panasonic cells is either you pay through the nose or you risk counterfeits from China.

[Sunking]

Lithium titanate might be longer living - it isn't clear that LiFePO4 would be longer living. But the clear issue is total ROI, which means both cycle life and acquisition cost. Lithium titanate is still very expensive, much higher than LiFePO4. While most of us can't source Tesla/Panasonic cells at $160/kWh, Tesla can do that since they bought about 2.5 GWh of cells last year. As a result, there is no premium. Tesla/Panasonic cells are simultaneously the highest specific energy and the lowest cost per kWh of the major high power, high current lithium ion products. Now, Tesla throws in a DC charge controller, packaging, liquid thermal management, and gross margin to get to $429/kWh (usable).

As the Gigafactory comes online, the cell prices drop further.

BTW, the head of Tesla's battery efforts used to work for Panasonic, both in manufacturing in Japan and heading up Panasonic's U.S. research lab. The cells are made by Panasonic to Tesla's spec, so they aren't exactly what you get in retail. The other problem with sourcing Panasonic cells is either you pay through the nose or you risk counterfeits from China.

I smell a RAT. 3 posters, just joined today. All post about Tesla. ~~~~~~~deleted~~~~~
RUSS who is this guy and Hub?

[J.P.M.]

You know they are on the run when you see the dust flying off the 30 year old resumes that are trotted out as proof of validity.

You're only as good as your last project.

[DanKegel]

I smell a RAT.

Yeah! He disagrees with us -- must be an ENEMY! Get out the tar and feathers!

[foo1bar]

EV is a second car for folks who have that kind of money to spend to feel good about themselves.

...
I have a NEV with Lithium batteries.

So - do you feel good about yourself for spending that kind of money?

Seriously though, the people I know that have an EV it's actually cost effective because they drive enough each day, and the cost of gas vs. cost of electricity more than makes up for the difference in vehicle price.

[solarix]

What I'd like to know is how they are going to integrate this new high-voltage (350 - 450Vdc) Tesla battery into a home system. I assume its going to be grid-tied, but I don't know of any current inverter that can work with this battery. They say SolarEdge is going to have something compatible. Great - another new, unproven item. I've been waiting for 30 years for a battery "breakthrough". God knows the industry needs it. Maybe this is it, but I'll stick with Trojan for now. This new industrial version sounds pretty good to me. The big advantage of lithium batteries is the much better energy density, but in a stationary application, who cares?

[foo1bar]

What I'd like to know is how they are going to integrate this new high-voltage (350 - 450Vdc) Tesla battery into a home system. I assume its going to be grid-tied, but I don't know of any current inverter that can work with this battery.

Seems pretty straightforward to me - those are voltages that work well for solar inverters, so I think it should be easy to adapt that for a battery source instead of solar panels.