FDK To Begin Mass Production of High-Capacity Li-Ion Capacitors (2000 Farads!)

www.greencarcongress.com ^ | 1-5-2009 | Staff

[TNoldman]

I wonder how the hazardous voltage levels will affect the “joe 6 pack” “shadetree mechanic” working on his new Hybrid? .....or an EMS Guy or Gal trying to rescue someone from a wrecked Hybrid?

[TC Rider]

Who would have believed they would finally run out of bad movies?

[Sawdring]

Didn’t Nikolai Tesla invent these things 90 years ago in his garage?

[norwaypinesavage]

"FDK announced its EneCapTen lithium-ion capacitor in 2007, offering an energy density of up to 25 Wh/L (14 Wh/kg)"

Just for comparison, gasoline is about 10,000 Wh/l and 12,000 Wh/kg. Where will anyone put all of the mass and volume of these great devices??

[grey_whiskers]

Like, *PING*, dudes.

Cheers!

[SunkenCiv]

The company anticipates that lithium-ion capacitors will be in demand as auxiliary power units for automobiles, as well as storage components that facilitate the transmission of electricity generated by wind turbines.

Thanks grey_whiskers.

[RobbyS]

One thing that is never made clear to the public is how much energy is contained in a liter of gasoline. Nothing now available in bulk can touch it.

[Myrddin]

That looks like a good candidate for running some of the actuators on my rail cars. Currently, I have a pair of 12V lead acid batteries trickle charging between activations. They are operated in series for 24 volts with sufficient amperage to operate a solenoid air valve or the gear motor actuator of the anglecock. Activations are infrequent and of short duration. Lots of "trickle" time between uses. That's perfect for a cap. The cap has a better temperature range and more cycles than the sealed lead acid.

[grey_whiskers]

Whoa, hold on one second, there!

I didn't even know you *had* rail cars, let alone that they needed actuators.

Can you give me more details, please?

Cheers!

[Nachoman]

The auto manufacturers will need this to illuminate all the idiot lights they have on the dashboard.

[Lexinom]

I remember acquiring a big 100,000 microfarad cap from some junk electronics someone was throwing out. Would charge it up @12V, take it outside, and short it - a re-useable firecracker, impressed my friends! (and yes, I’m a nerd and proud of it!)

[neverdem]

Thanks, Happy New Year!

[dayglored]

> I remember acquiring a big 100,000 microfarad cap from some junk electronics someone was throwing out. Would charge it up @12V, take it outside, and short it - a re-useable firecracker, impressed my friends! (and yes, I’m a nerd and proud of it!)

A few decades ago I designed high-power inverters to drive 460VAC 3-phase 400-HP induction motors. Phase-controlled front end made a 600VDC internal bus, and it was buffered by a capacitor bank that was around 50,000uF.

Sometimes the inverter would sense a bad condition and shut itself off while operating at full speed, meaning that the capacitor bank would be sitting at around 600V with nothing to discharge it -- the inverter wouldn't allow restarting until the cap bank was discharged as a safety feature.

50,000uF at 600Volts -- energy is 1/2 CV^2 as I recall...

For regular operation there was a bleeder resistor coil that took about 15 minutes to drain the caps. Suffice it to say that during development, we engineers get impatient...

So one of the techs fashioned a "chicken-stick" out of a foot-long piece of solid copper buss bar, with a cross-section of about 1-inch by 1/4-inch. He wrapped one end with electrical tape to make a handle grip, and we would use the other end to short the capacitor bank (right across the main terminals!).

It was called a "chicken-stick" for a good reason. Nevermind the fact that you were sticking your arm into a 600Volt live chassis... the "crack!" when you made the short was enough to make the biggest guy on the team drop a load on the spot.

Nowadays the guys work on 5V low-power systems. Bunch of wusses... ;-)

[Lexinom]

Those must have been some spectacular and large caps. IIRC placing caps in parallel increases capacitance but decreases maximum voltage; placing in series has the opposite effect. So five 10,000 uF caps in parallel would have to be rated at 3000VDC.

Chicken stick - perfect name, and completely understand the patience factor! That must have made for some interesting spectacles.

[Myrddin]

My rail cars are part of the Federal Railroad Administration R&D project. The sensor/actuator elements of the system are based on PIC microcontrollers running a CANopen stack (CAN bus) to control handbrake (set/release), anglecock(open/close), cut lever(release), brake piston position sensor (home/applied/overtravel), bearing temperatures (RMS/peak), triaxial accelerometers(longitudinal/lateral/vertical axes) with RMS/peak acceleration in Gs, a smart battery charger with tachometer input from a Timken bearing generator and Timken regulator and a PC104 running Linux as the master CANopen node to collect data and control the system. The PC104 also does high speed data acquisition (50 KSPS) on the vertical accelerometer (+/- 80 Gs) for vibration signature analysis. Each car has a full time GPS for tracking and time, 1xRTT CDMA radio for internet connectivity, 802.11b wireless LAN running OLSR mesh networking to communicate with the locomotive. Locomotive/car data run over RTI's NDDS publish/subscribe middleware on top of the mesh to allow for loss of line-of-sight connectivity.

I'm currently cooking up some RF wakeup modules based on 802.15.4 with AODV style mesh networks. Those radios permit the locomotive to determine which cars are in the area, whether they are on the same track and which end (A or B) is point toward the locomotive. Cars that are on the track get a remote wakeup request to launch the PC104 and CAN devices so unattended pickup/dropoff can be accomplished. No brakeman required :-)

[Myrddin]

I charged up the Sprague "orange drop" caps with my Ford Model T spark coil. I put the charged caps in a paper bag on my desk. A few "curious" folk discovered a wallop waiting in the bag. Old tube type televisions were loaded with lots of great parts. Orange drops included. It was a real treasure trove of parts when I was in elementary school.

[Myrddin]

There's nothing quite like a central office battery string with -48 V at 5,000 amps to command a little respect. The power buses are laminated aluminum to make them stiff enough to not twist from the magnetic field generated by the high current. One wire chief related a story of a crescent wrench accidentally dropped on the bus. Vaporized. A very loud crack and very unnerved observers.

[Mr170IQ]

For the less math/physics inclined of our readers, lets just compare the FDK Li-Ion capacitor to the tried-and-true automotive lead acid battery.

In order to replace a 20 pound automotive battery (in terms of total energy) , you would need about 45 pounds of this kind of ultracapacitor, taking up nearly three times as much space. This ultracapacitor is able to deliver 50% of its total energy output in just four seconds (about 175 horsepower!), while the lead-acid battery would have a maximum sustained power output nearly 100 times smaller.

However, lead-acid batteries tend to wear out after far less than 1000 deep-discharge cycles, i.e. an electric car with lead-acid batteries that gets recharged every night would need batteries replaced every 2 years. These ultracapacitors last almost 1000 times as long.

Capacitors are also far more efficient. A lead-acid battery will typically return less than 80% of the electricity that was used to charge it, IIRC. The rest of the energy is lost as heat. As they mention in this article, a capacitor can return 99.9% of the energy used to charge it.

As mentioned by others, this kind of ultracap seems ideal for regenerative braking in hybrids that do a lot of stop+go traffic (city buses for example). It could also replace the conventional battery in a gasoline or diesel car. But it still has insufficient energy density to replace batteries in a plug-in electric car, unless you can arrange to recharge every ten miles - which is not impossible - charging takes about ten seconds if you have enough power coming in.

[grey_whiskers]

I'm impressed. Are you sure this is a *Federal* agency? l;-)

(Saunters away, humming "I've been working on the Railroad"...)

Cheers!

[grey_whiskers]

I'm impressed. Are you sure this is a *Federal* agency? ;-)

(Saunters away, humming "I've been working on the Railroad"...)

Cheers!