View Full Version : Random battery thoughts

08 October 2014, 1421
As you know, Tesla will be building a battery gigafactory in Sparks, Nevada to make lots of batteries for their production cars. Now a report in my newspaper written by Dana Hull (mercurynews.com) says that Panasonic will be initially investing hundreds of millions of dollars into the factory, with more to come in the future. My guess is that the batteries coming out of this factory are not going to be available to Zero, Brammo, or you and me, but will be used in mass production automobiles and other products. No doubt investors in the factory will have first dibs on its production for many years into the future.

So my initial thought would be that this factory is not going to be helping us little guys all that much. But then it occurred to me that Tesla and Panasonic are not the only game in town and if they start producing high quality, low cost batteries then other battery manufacturers will need to do the same to remain competitive and continue in business. I figure that their products will remain available to low-volume purchasers, such as motorcycle manufacturers and hobbyists in the future. It may even be that smaller battery manufacturers may more easily be able to adopt to new battery technologies quicker than a gigafactory that is designed to produce millions of units each year. Once you get a big ball like that rolling, it may be tough to change course. ;)

08 October 2014, 2032
Interesting points. I definitely hope that's the case. Prices will come down as volume goes up, and manufacturing gets cheaper across the board. Whether that happens for companies that will sell to us depends on whether there is enough demand for them to increase production. Zero or Brammo might get a piece of the pie, but what would really help is if, say, Honda decided to build a production elmoto. Or Harley...oh wait...

Unfortunately, what might happen is that as production bikes get better and cheaper, there will be fewer DIYers and companies that will sell to them. Basically because there won't be much overlap between cells for OEMs and cells for DIYers, and the DIYers will get shut out.

Panasonic is very protective of their cells, and their reputation. They won't even talk to little guys, partly because they don't want to do small volume, and partly because they want to make sure anyone using their cells REALLY knows what they're doing. You know how much bad press Tesla has gotten from just a few fires. Imagine if there were a million Youtube videos of people blowing up their Panasonic batteries.

[edit - Apparently I'm wrong, you can get Panasonic cells, through various distribution channels.]

The hope is technology will trickle down and DIYers will get better products and prices over time. Or, we hope for opportunities that let us obtain the unobtainium (e.g., Leaf cells).

09 October 2014, 0137
With the volume that place is getting geared to produce, I reckon that whilst they'll have preferential technological agreements with the main partners (ie: they get the newest stuff first), they're going to sell to EVERYBODY. You'll just find that what you get if you're not a partner will be effectively the previous generation tech.

09 October 2014, 0817
My thought is that the NCR18650B cell used in the Telsa is already VERY VERY VERY high volume....used in Laptops, tools, flashlights. Whats surprising is they aren't cheap! (for us). I bought a few from ebay just to try $12 each....mine turned out to be Chinese fakes yielding barely over 2ah (spec is 3.4). What is cool is that you can get them in a "protected" version. I small PCB on the bottom of the cell montiors HVC & LVC and maybe temp. I connected one of my cells to a 5v supply....when the cell hit 4.25v the cell circut tripped and disconnected the cell. After doing some digging I found out the 18650 size cell is copied by so many thet without a good connection, you wont know what your getting!

09 October 2014, 0901
18650 is just a size definition. It's 18mm diameter x 65 mm long. They can be all sorts of chemistries. Tesla uses nickel cobalt aluminum (NCA) in the Model S, cobalt oxide in the Roadster (as far as I know).

A123 makes LiFePO4 18650s. They are VERY powerful, much more than you would expect from LiFePO4. There are lots of other 18650s.

I was under the impression Panasonic didn't want it's cells out of control of approved OEMs, but I could be wrong. I guess the trick is finding genuine NCR18650s (and then, wiring 100s or 1000s of them together).

09 October 2014, 0934
I have a bunch of LG, Panasonic, Sanyo and Sony 18650's on my desk - they're all the genuine article and all readily available from certified resellers on alibaba and similar. You pay more from the certified resellers becuase you get the security of knowing you're getting the genuine article although I've bought legitimate cells from uncertified sellers as well, but only in very small quantities, as you don't have any assurance until you have them on the bench and load tested in that circumstance.

09 October 2014, 0946
Huh, apparently I had the wrong impression (post edited above).

I got the impression you couldn't after talking to a Panasonic rep. But they might have meant we won't sell you 100 cells period, and we won't sell you 100,000 cells unless you're an approved OEM.

09 October 2014, 1104
Sure, Im aware of what 18650 means. Point was there are SO MANY vendors making BILLIONS of these cells you expect them to be cheap and easy to get.

10 October 2014, 0545
To be fair, there's every possibility that what's being sold is excess from chinese approved OEM's - so they're not necessarily dealing with Panasonic for resale but rather for direct application, and then just selling anything over whatever they need, having made any purchase quantity based on whatever was required to achieve a given price break.

Huh, apparently I had the wrong impression (post edited above).

I got the impression you couldn't after talking to a Panasonic rep. But they might have meant we won't sell you 100 cells period, and we won't sell you 100,000 cells unless you're an approved OEM.

10 October 2014, 0908
Could be. There's all sorts of gray market stuff going on with batteries.

You can get LG and Panasonic cells from batteryspace.com (http://www.batteryspace.com/18650seriesli-ioncells--oemfromjapankorea.aspx), as well as cheaper, lower energy generics. Genuine? Approved vendor? I have no idea...

10 October 2014, 1158
Leaf cells looking better and better!

24 November 2014, 1430
I have just recently been contacting LiFePO4 sources in China because that is the next step for me on my ev emc project.
My take on this whole topic is that there needs to be some industry wide standardization for these cells to become cheaper in the long run.
I envision 50 volt bricks that come in different ah ratings. These bricks must be able to be wired in series circuits and in parallel circuits, and in any combination of the two.
As long as the ah ratings stays the same, it shouldn't be a big deal. The BMS boards should have a switch on them so that the battery brick can be switched from series to parallel.
Anderson already makes keyed, colorcoded quick disconnect plugs, so keeping the different rated bricks separated can be easily done by standardized color coded plugs.
If an emc manufacturer knows ahead of time the size, voltage and output of the bricks, then the available battery space can be optimally utilized by proper positioning of the bricks, and this can be done in the design stage.
Bricks can be mounted to removable fairing panels and side panels. Or BMW type hard side panniers can be added for increased range, and removed for daily commuting.
Standardization is the key to the success of the industrial revolution, with the invention of interchangeable parts. Thats what I personally need for my project, so I'm sure I'm not alone here.
The whole industry just needs to get organized and things will get very exciting, very quickly indeed :cool:

28 April 2015, 1542
Moving towards the 18650 standard only makes sense for small EV applications. It's like the Beta VHS battle all over! 18650s have been around for nearly two decades and are so common in the portable electronics and power tools industry that it does not make sense why other formats were ever produced...

Cylindrical cells are mechanically self-contained, are abundant, cheap and above all STANDARD!
It is proven to work. You can design for one cell and turn around to anything else, yet there is nothing to change to you design! :)
A smaller form factor is great for filling space and has a lower temperature gradient within the cell.
Plus, you can match the cells better and have no single point failure because for large power applications they need to be put in parallel.

Of course the close minded might argue that there are more connections to make... But there are always trade offs in life!

As you might understand, we are moving away from the Hobbyking cells to refocuss on a new design using 18650 cells.

30 April 2015, 0939
What Tesla is doing is going to be good for all of us. Right now we are able to get cells/bricks from a Chevy Volt or Nissan Leaf for about $0.25-0.30/wh in larger format and very well engineered and tested.

The DIY'r world is so miniscule, we do not matter. But as more vehicles and batteries enter the market, there is bound to be more opportunities for us to get a hold of quality batteries. We already have guys taking apart Tesla's packs to resell to us.

Personally, I have no interest in handling single little cells anymore. It's just way too much work without the economies of scale and production methods of manufacturers.

It would be cool to get a standard going. Like swapping bricks between your lawn mower and ebike.

The DIY scene and even Zero will be dwarfed overnight the moment one of the big Jap bike manufacturers come out with a elmoto. I still see that as a really good event for all of us.

30 April 2015, 1926
I couldn't agree with veloman any more. For all of us DIY'rs, the future is so bright, you gotta wear :cool: !!