New High capacity Li-Ion high cycle count

[microbrain]

Hi everyone, i'm mostly a reader around here, i've made some projects of my own, and now that i have more free time, i will try be more active and helpfull for this great forum.
I'm 31, from portugal, experienced in AVR's c and Computer software development. corently own a E-bike with a golden motor in it.


The reason for this post is this news i saw today ....

http://www.ntsworks.com/New_Battery.html

Hope this isnt a hoax.

[Paul_G]

mechanically connecting cells together with pressure

http://green.autoblog.com/2012/05/18/ne ... e-costs-l/

[Jeremy Harris]

Also posted here, with a link to their website (which doesn't say much, unfortunately): viewtopic.php?f=14&t=39980

[flathill]

just need to gold plate the battery terminals and we should be all good
Neal mentions he needs investors and want to sell to DIYers but can't get around the liability issue
should just sell it kit form

[Joe Perez]

The problem has been that cylindrical cells are hard to electrically connect together. The traditional way to interconnect them is with welded nickel strips. The drawback to this is that the electrical resistance is high, the welds break easily and welding together thousands of cells is very cumbersome.

So, spot-welded connections have a higher electrical resistance than two pieces of metal simply pressed against one another?

The ability to just pop cells in and out of a pack as though you were replacing the cells in your personal massage wand is certainly appealing, but when claims like the above are used as justification for any new technique or technology, it certainly makes me wonder about the underlying ethics and mindset of the company.

[John in CR]

just need to gold plate the battery terminals and we should be all good
Neal mentions he needs investors and want to sell to DIYers but can't get around the liability issue
should just sell it kit form

I just want the 30ah 4s modules already in production and soon to be coming out of a US factory....good for thousands of cycles, safer than lifepo4, 160wh/kg, self balancing, and capable of 125A continuous. The only thing a pack of 18650's could have on them is more latitude in pack shape. I'm sworn to secrecy for now, but don't spend too much on batteries at this time. There's finally light at the end of the tunnel unless you need extreme power density.

John

[CamLight]

Welcome to the ES forums!

If I read that article correctly, there's nothing new about the cell's they're using, just the way they connect the cells (and even that's been around for a while). They're using standard 18650 cells and connecting to the cell terminals via pressure instead of soldering ( ) or tab welding. With 1,440 cells for their electric morotcycle pack and (if I calculated correctly) about 10,000 cells for a car pack, I shudder to think about the pack's reliability with just pressure against the cell ends for the connections. Especially with all that vibration/shock.

But perhaps 18650 cells do have an energy density advantage over other cell sizes/formats?

[neptronix]

Guys, they are using cells which are not really capable of more than 1C continuous, and will be rated for max life around something like 0.5C. The terminals do not have to carry a lot of current, and the pack will have to be massively oversized for whatever electric vehicle application they are used in.

This is the Tesla approach; super oversized low discharge rate battery. The cost ends up being low per kW-hr, but you need a hell of a lot of kW-hrs.

[neptronix]

They conveniently leave out the fact that the C rating on those batteries is awful and that you need a massively oversized pack to get the same equivalent discharge..

This is the Tesla approach. Stinking huge battery of a lower C rate, to get high mileage. You can't go small on this battery or it will die an early death. It is cheaper per KW-Hr, but you need a lot of KW-Hrs to get decent output.

[Hillhater]

Guys, they are using cells which are not really capable of more than 1C continuous, and will be rated for max life around something like 0.5C.

I wonder why they limited themselves to the older tech cells ?
Newer 18650's can output 2-5C rate continuous, and obviously the A123's could supply much more.
I guess pressure contact technology would not be reliable at more than a few amps.

[neptronix]

Guys, they are using cells which are not really capable of more than 1C continuous, and will be rated for max life around something like 0.5C.

I wonder why they limited themselves to the older tech cells ?
Newer 18650's can output 2-5C rate continuous, and obviously the A123's could supply much more.
I guess pressure contact technology would not be reliable at more than a few amps.

It's newer tech. 250WHr/KG is cutting edge, as in, within 1 year old. A pack of those makes our 150WHr/KG RC Lipos look huge. It's what Tesla will be/is using in their cars ( which is why their packs are so large. )

Meanwhile, those 2-5C continuous 18650 cells you're talking about? They tend to store 130-175wHr/KG, coming in within what RC Lipo is at, in terms of size and weight.

In lithium batteries, as of writing, you can have high power, or high energy, but not necessarily both. The 'have your cake and eat it too' cell does not exist yet.

[Hillhater]

The Panasonic 3.1 Ahr (NCR18650A) is rated for 2C ( 6.2A ) discharge ,..
and their 2.2Ahr CGR18650 is rated for 10A continuous ( 4.5C),
...so you get a choice of increased capacity or higher output.
Whilst the weight /size comparisons to RC lipo are valid, the point is that this system could lend itself to high capacity DIY pack builds using easily replaced , proven cells without a "spaghetti factory" of wiring connections.
RC Lipo will still win for cost and discharge rate, but this system could have advantages for weight in large packs.
However you would need to find a killer deal for cells to make the price reasonably bearable

[auraslip]

a "spaghetti factory" of wiring connections.

I hate the spaghetti factory, and not just because I'm on a low carb diet.

[neptronix]

The Panasonic 3.1 Ahr (NCR18650A) is rated for 2C ( 6.2A ) discharge ,..

Sure.. it can technically do 2C for a period of time, if you cool it and accept the fact that you're gonna lose *tons* of watt hours as waste heat

That 3.1AH capacity is rated at a 0.2C discharge. Discharge at 1C and you only get 2.8AH out of the cell, and it sags like crazy.

http://www.candlepowerforums.com/vb/showthread.php?338240-Test-Review-of-Orbtronic-18650-3100mAh-(Black)

Here is a spec sheet.

So yeah i'd consider them a 1C maximum cell. This is OK if you are going to build a wickedly huge pack. But it will definitely cost you $$$ to do so, unless you buy in super huge quantities.

Sorry to take a dump on your rainbow.

[csm]

just need to gold plate the battery terminals and we should be all good

That is a brilliant idea! the gold could be re-cycle if needed. Perhaps could be DIY project.

[csm]

The problem has been that cylindrical cells are hard to electrically connect together. The traditional way to interconnect them is with welded nickel strips. The drawback to this is that the electrical resistance is high, the welds break easily and welding together thousands of cells is very cumbersome.

So, spot-welded connections have a higher electrical resistance than two pieces of metal simply pressed against one another?

I have read reports that the spot welding process can cause an internal damage to the cell which can result in more internal resistance. I am not sure how to prove this.
I too am puzzled why we haven't seen more pop in batteries, like nimh. I suppose it has to do with trying to limit potential liability issues of people sticking them into chargers that over charge? Or sticking cells together that would be imbalanced? Perhaps with the newer lithium chemistry and more advanced charger technology, this will no longer be an issue? Perhaps cells could be embedded with RFID that communicates with the charger to give the important info on charging(voltage, AH, C charge rate).. and if it does not have the RFID tag, it just will not charge?

[dogman]

Swimming with the sharks now eh? But the comments are correct. We've all been around the block a few times here, especially when the only source of good c rate cells was dismantled drill packs. A lot was learned about good and bad ways to make connections on little round cells. Mostly though, small round cells are a real pain. At least use 2 ah cells or larger.

When decent c rate RC lipo that didn't explode hit the market at good prices, we flocked to it like geese to a corn field.

Similaly, a lot of folks are now looking hard at 20 ah A123 pouch lifepo4 now that you can finally get your greedy hands on it.

What's hot here changes a couple times a year sometimes.

[Pablo_1985]

http://www.ntsworks.com/New_Battery.html

I get there from here:
http://green.autoblog.com/2012/05/18/ne ... #continued

It seems to be the same guy who developed Zero motorcycles.

Regards

[Lock]

http://www.ntsworks.com/New_Battery.html

Breakthrough Interconnection System
The problem has been that cylindrical cells are hard to electrically connect together. The traditional way to interconnect them is with welded nickel strips. The drawback to this is that the electrical resistance is high, the welds break easily and welding together thousands of cells is very cumbersome.

Our new patent pending interconnection system is entirely different. We mechanically connect the cells together with pressure. It is very difficult to make a reliable pressure contact that can carry up to 10 amps and do it for pennies of cost. This was an incredible challenge.

Hmmmm....

Upgradeable And Reusable
Having a standard sized cell that is easy to replace also means that when newer higher energy cells come out, it's easy to upgrade. There are already 4.1 ah versions of the 18650 cells due for production in 2013. This will be a 20-25% increase in energy density.

Hmmmm....

Neal T Saiki
Neal Saiki is a proven innovator of electric motorcycles, full suspension mountain bikes, rock climbing gear and numerous other products. HIs goal is always to always to refine technology until it is simplified elegance. In his spare time, his interests include martial arts, mountain biking, motorcycles, jewelry design, rock climbing and airplanes. Combining work and play has always been the common theme among Neal's endeavors.
SNIP
In 2005, Neal worked on electric motorcycles and founded Zero Motorcycles. Zero has become the leader in this fledgling industry. He retired from Zero in 2011 in order to resume working full time on the human powered helicopter.

[docnjoj]

hmmmmmmmm... is right L0ck! Seeing will be maybe believing. If accurate and true it could help thos folks who like soldering together hundreds of connections. Not me anymore.
otherDoc

[deVries]

Here's a thread where I try to follow any battery capacity breakthroughs... If you haven't seen it yet, then you can find more related info there:

Attn Experts: When Will Battery Capacity Double ?

This NTS breakthrough seems to be more related to battery design & getting more efficient cell connections! Huge improvement if 15kWh gets you 100 REAL miles.

[Lock]

From here:
http://www.ntsworks.com/Bicycles.html

World Class Bicycle Design
Although not widely publicized, Neal Saiki has been the designer behind dozens of world class bicycles for high end brands such as Haro, Santa Cruz and Mountain Cycles. Neal's product development business developed bicycle designs which would be sold or licensed to established brands.

Neal has been a long time motorcycle enthusiast and combining motorcycle suspension technology with bicycle design has revolutionized the mountain bike industry. In 1994 Neal designed one of the early full suspension mountain bikes and for the next fifteen years he has been at the leading edge of bicycle design.

...yet the emphasis at NTS seems more motorcycle-class... Perhaps the mechanical connection isn't rugged enough for bicycles, but do-able for larger road-going eMotorbikes

L

[Jeremy Harris]

We now seem to have three threads running on this topic, perhaps we could merge them?

(the other two threads are: search.php?&sr=topics&search_id=newposts&start=50 and viewtopic.php?f=14&t=39980 )

[neptronix]

please merge them

[Pablo_1985]

Merge them please, i did not see the other ones :S