Hi there!

Welcome to my ENVIRONMENTALLY SAFE, FOREVER RECHARGEABLE

SUPER CAPACITOR BATTERY PACK INSTRUCTABLE!!!

What's all the Hubbub, bub?

This circuit acts as a never-dying, forever rechargeable battery. If treated properly

and with respect, it will live longer than you do! That's right! You will die before this

variable battery does! Eerie, eh? The circuit employs about $90 worth of circuitry,

but it sure beats buying batteries. I use this circuit every single day when I get

home from work to listen to music. Depending on your input charging method (DC,

solar, etc), charging can take only minutes. With this, I can listen to music out of

my computer speakers at high volume for about two hours before having to re-

charge. Use it to charge your cell phone. Use it to power your radio! Use it as a

portable power supply! Wire it up to a flash light, or use it to power your halloween

costume! The possiblities are endless! I am selling this in kit form! See the last

page of this instructable for details.

YOU VARY THE OUTPUT VOLTAGE!

Need 3v? You got it!

Need 9v? You got it!!

Need 12V? You got it!!!

(http://cdn.instructables.com/FLM/E88Q/GJQEJNV4/FLME88QGJQEJNV4.LARGE.jpg)

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Hi there! My name is Patrick, and I aman electronics engineering technician whoworks full time as a lab tech, and part timeas an electronics engineer/salesman. Iown an ebay store, and two website...readmore » (/member/EngineeringShock/)

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Need 34V??? You got it!!!!

HOW DOES IT WORK?

The circuit uses SUPER CAPACITORS, as opposed to batteries. Super capacitors

are like other capacitors, only they have enormous power storage capabilities.

Capacitors have two storage variables: Maximum charging voltage and capacitance

(Measured in Farads). Capacitance is a measure of how much energy can be

stored in a capacitor. A typical power supply capacitor or audio coupling capacitor

would have a capacitance of around 0.0001 farads, which is relatively large. A

super capacitor normally has a capacitance of between 1 to 3000 farads, which

make them good substitutes for batteries! We are going to safely charge 2x 400

farad capacitors in series up to 5.4VDC, and feed that voltage through a DC-DC

booster circuit. We are also going to employ a digital voltage display that will be

able to read both the charge on the capacitor bank, as well as the voltage at the

output of the DC-DC booster. Let's go over SOME of the pros and cons of super

capacitors, shall we?

PROS OF THE SUPER CAP:

1) As long as you don't charge them at a voltage higher than they are rated for, or

reverse charge polarity, super capacitors can have charge/discharge cycles of

500,000-1,000,000, or more!

2) If you charge a battery and leave it in the charger, you can deplete battery

memory, and it will eventually die. The super capacitor will STOP accepting any

energy once it is full.

3) The internal ESR (Internal resistance) is extremely small in a super capacitor.

We're talking 0.01 Ohms or less. A typical battery has an internal ESR or 0.02

Ohms - 0.2 Ohms. Why does this matter? If means that you can potentially

charge a super capacitor in seconds, providing you have some heavy duty power

supplies. Batteries take longer to charge, and cannot discharge as quickly.

4) Batteries have a shelf life. If left fully charged on a shelf for years, you will pick

it up one day and find it dead. Not so with the super cap!

5) Super capacitors give off no emissions, while all batteries give off some form of

gas. You can't keep your car battery in your house, but you can keep your super

capacitor bank in your house =)

6) If you cause a direct short along your super capacitors, they will not blow up or

be harmed. They are made to do just that. However, immense heat will be created

along the short, as enormous amounts of current will be very quickly dissipated.

This is also a con, because the user can be burned if not careful.

7) They are environmentally safe.

8) There are so many pros and so few cons, but we don't have time to go over them

all =)

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CONS OF THE SUPER CAP:

1) If you made a super capacitor big enough to replace your car battery, it would

likely be 10 times the size. Super capacitors have lots of energy storage, but need

to be banked in series/parallel to achieve battery-like storage.

2) super capacitors normally have very low max voltage ratings, which means that

you have to be very careful not to over charge them. As well, what are you going

to do with a 2.5v capacitor? You have to place a bunch in series to keep doubling

the voltage. However, when you add capacitors in series, you lose capacitance.

The formula for series and parallel banking will be in the final step, so if you have

time, have a look =)

3) While you need not worry about shocking yourself, as super capacitors offer so

little voltage, you can burn yourself if you create a direct short on a fully charged

super capacitor or bank of capacitors.

4) Super capacitors are more expensive than batteries.

THIS INSTRUCTABLE WILL BE BROKEN DOWN INTO 4 PARTS:

1) The Charging Circuit

2) The Capacitor Bank and the DC-DC Booster

3) The Digital Voltage Display

4) The Parts, the Math and the Conclusions!

If you are interested, most of these parts can be found in my ebay store, which

can be found here: http://www.electroniclessons.com/

(http://www.electroniclessons.com/)

Check Out My Improved 1.5A 18 Watt Charger!

Step 1: THE CHARGING CIRCUIT

THE CHARGING CIRCUIT:

Let's go through this in steps. It is actually very simple but you have to follow along

closely, especially as we go into the step on the following page.

We start at TERMINAL BLOCK#1 and will continue clockwise around the

circuit!

1) This is where you have options. We need a DC source of anywhere between

5VDC-20VDC for our charge. I use a 11VDC@1A power supply, but I

occasionally use a set of mini solar panels that I have in my window. The choice is

yours. Just make sure that when you plug in your DC source, you are making

sure that you have the correct DC polarity for DC+ and ground (DC-).

2) We have a 0.1uf capacitor and a 100uf capacitor in parallel with the input DC

line. We only really need these because this line is for the charging of the

capacitor bank, but we will be using this input line to power our digital display and

we want to make sure that this DC line is smooth and without extra noise. The 0.1uf

capacitor takes care of high frequency noise, or rather, lessens it (Decoupling

capacitor). The 100uf capacitor acts to smooth the input DC. These two

capacitors are not really necessary but they are preferred.

3) The LM317 is a variable DC-DC power supply. Using a 240 Ohm resistor in

parallel with the VOUT and the ADJ line, and a 5k ohm variable resistor from the

ADJ line and ground, we can vary the charge voltage from the charge voltage itself,

down to 1.25v. For instance, if we have 8v at the input, we can vary the output

anywhere between 8v down to 1.25v. It is EXTREMELY important that your LM317

is properly heat sinked, as it will get HOT. The LM317 kit can be found here:

http://cgi.ebay.com/DIY-LM317-Variable-DC-power-supply-kit-PCB-Parts-

/180609634986?pt=LH_DefaultDomain_0&hash=item2a0d2c52aa

(http://cgi.ebay.com/DIY-LM317-Variable-DC-power-supply-kit-PCB-Parts-

/180609634986?pt=LH_DefaultDomain_0&hash=item2a0d2c52aa)

4) Varying the current to the super capacitor bank is the name of the game. This

is where you have the opportunity to gamble. Since the super capacitors will

literally suck up all the energy it is given until full (With >0.01 Ohm ESR), we have

to limit the current from the supply, or else we're going to completely destroy our

LM317 circuit. As you can see, we have two 2.2 Ohm, 5W power resistors, a

jumper, and a SPST (Single Pull Single Throw) switch. If the switch is off

(Recommended), and the jumper is not attached, then the charge limitation is 2.2

Ohms. Wait a minute! That is too small of a current limiter! You're still going to

hurt your LM317!!! Not the case! If properly heat sinked, the LM317 will get hot

but it will withstand the stress if you have this 2 Ohm load. The output voltage will

(http://cdn.instructables.com/FP6/2A1X/GJQEDDDO/FP62A1XGJQEDDDO.LARGE.jpg)

drop down but you will see it come back up as the capacitor starts to charge. We

have three charge options here. If you have a charge of 4v or higher, make sure

that you have the jumper off, and the switch off.

A) Charge limited by 2.2 Ohms when JUMPER=OFF/ SPST=OFF

B) Charge limited by roughly 1.1 Ohms when JUMPER=ON/SPST=OFF

When you add the jumper, you place the two 2.2 Ohm resistors in parallel with one

another, bringing the parallel resistance down to half. Please note that these

resistors get hot.

C) Charge limited by the line resistance and capacitor ESR only

when JUMPER=ON or OFF/SPST=ON

If the SPST is switched on, it doesn't matter how the resistor jumper is configured.

The only resistance between the output of the LM317 and the capacitor banks is

the line (trace) resistance, and the ESR of the capacitors (Yet to be seen). This is

where you have to have cohones! Again, your LM317 can handle this if properly

heat sinked (Heat sink included in kit), as the output voltage will drop down to the

cap voltage and start to charge. However, this should only be used for charges of

1.5v or less. If you are charging the bank from 0v to 5.4 v, it will charge relatively

quickly using the 2.2 Ohm charge option. However, around 3v of charge, it will

start to slow down. At this point, take the jumper off to limit the current to 1.1

Ohm. At around 4.5v, you will notice that the charge will slow down again. Flick

the switch to charge the remaining 900mv, and you will have no problems. Truth be

told, I've charged from 2v to 5.4v with the switch on, but it is NOT good practice,

and I was risking my LM317.

5) We have two IN4001 diodes in series with the charge line. These are not used

for any type of rectification, but rather to allow DC charge to enter the capacitor

bank, but not allow for any DC to travel backwards through the circuit after the

capacitor bank is charged. If we didn't have these diodes here, follow the circuit

backwards. Regardless of whether the jumper is on or off, or whether the SPST is

on or off, there is a path back to the LM317, and there is a 240 Ohm resistor in a

series path with a 5k potentiometer and ground. If we stopped charging (without

the diodes), the charge on the caps would leak back through the circuit to ground,

making our batteries terribly inefficient. There are two diodes in parallel to share

the current along the line. If you have 1N4007s, or any 1N400X diodes, they will

work just as well if not better. There are factors such as thermal runaway that we

could spend time worrying about with these diodes in parallel, but the charge time

from start to finish for this circuit is literally 10 minutes or less , so we're not going

to worry about that at all.

6) The jumper (JUMPER#2) like a lot of this circuit is a custom option. If you are

not going to watch the digital display (Seen later) as your super capacitor bank

charges, then you are going to want to follow this step. When you build this charge

circuit, probe the output of the diodes (TEST POINT) with reference to ground

using your multimeter. There will be a voltage drop along the diodes, so we need to

make sure that we measure here, and not at the anode end of the diode. Since we

have a 5.4v MAX capacitor bank, we DO NOT want to have a charge higher than

5.4v. Check the voltage here using the 5k potentiometer at the LM317. Turn the

potentiometer until you see a voltage of 5.2v-5.4v, then consider using a bit of hot

glue to set the pot to steady it. You may think, why use the pot, and not a fixed

resistor? You can, by all means, but you may want to change the charge voltage

down the road. Now, the jumper is here because on the other side of the jumper

lies the capacitor bank. If you test the voltage here when you have the jumper on,

you will read the voltage at the capacitor bank, not the voltage that it will be

charging to. You only take the jumper off when you want to take a charged

reading. Leave it on at all other times.

Step 2: The Capacitor Bank, and DPST Switch, and theBooster Circuit

THE CAPACITOR BANK:

As you can see, we have the capacitor bank circuit here on the left hand side of

the below schematic. It is comprised of 2x 400 farad 2.7v super capacitors, found

here: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180566348151

(http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180566348151)

When connected in series, these capacitors will form a bank value of 200 farads at

5.4v. This means that we have doubled our maximum charge voltage (2.7v *2 =

5.4v), and halved our capacitance from 400 farads down to 200 farads. If you

want to learn more about series/parallel capacitor theory, go to the final page of this

instructable. We need approximately 3.4v to power our DC-DC booster circuit.

This means that our booster circuit will work between the charged range of 3.4v to

5.4v, which means we can afford 2v loss before the booster circuit cannot boost

anymore. There is an arrow coming from the positive side of the capacitor bank

that indicates that this is the charge reference. This is just an indicator and is not

connected anywhere.

THE DPDT SWITCH:

Just to the right of the capacitor bank, you will see what looks like a piece of lego

with 6 little holes in it. This is my own little schematic symbol for a Double Pull

Double Throw switch. As you can see, there are little arrows coming from the

upper and lower middle circuits. These are the wipers (or PULLS). When in the

off position, the wiper on the top is connected to the upper left pin (as seen in the

picture), As well, when in the off position, the bottom wiper is connected to the

lower left pin (as seen in the picture). When you press the DPDT switch on, the

wipers connect to the pins on the right hand side. These switches are independant

of one another, but are located in the same package, and are switched on and off

at the same time. These only cost a buckand can be purchased with anything from

my store.

The top switch (Top left, middle and right pins) act to connect power to the DC-DC

booster board. The bottom switch (Bottom left, midle, and right pins) act to supply

the digital voltage reader with either the charge voltage of the capacitor bank (when

switched off), or the DC booster output voltage (when switched on). The digital

voltage reader will be talked about more on the next page. This switch business

may sound tricky, but follow along with the schematic, and you'll be in good shape

=)

THE DC-DC BOOSTER:

This is where things start to get easy! As stated earlier, this DC-DC booster circuit

will boost any voltage at the input between 3.4v MIN to 34v MAX to any voltage

between 3.4v and 34v. The output can be adjusted by using an on-board variable

(http://cdn.instructables.com/F4H/T4ST/GJQE96WA/F4HT4STGJQE96WA.LARGE.jpg)

resistor. All you need is to turn the pot!

Examples:

VIN = 3.4v VOUT = Any voltage between 3.4v and 34v

VIN = 28v VOUT = Any voltage between 3.4v and 34v

VIN = 8v VOUT = Any voltage between 3.4v and 34v

VIN=3v VOUT = 3v (Input voltage is to small to boost)

These booster boards are available in my

store: http://stores.ebay.com/hobbytronixstore

(http://stores.ebay.com/hobbytronixstore) There is a three-pin screw-type

terminal block for safe connection, and a variable resistor that allows for you to

change the output voltage for your desired application. The three pints are labeled

VOUT/GND/VIN. So, VOUT is your varied output, GND is common ground, and VIN

is your input voltage pin; requiring at least 3.4VDC. It is VERY easy to use.

DIMENSIONS: 32x34x20mm. It can supply up to 3A of current, but that is not

suggested for continuous draw. It is highly suggested that you keep continuous

draw under 2A. This bad boy is rated for 15W and has an efficiency of 90%. As

you can see, when the switch is flipped on, power is connected to the VIN terminal

of the DC-DC booster board. The second terminal of the board is connected to the

ground line, and the third is connected to our output terminal block. There is an

arrow coming from the output line that is labeled "BOOST REF". This is just for

reference and is not actually connected elsewhere in the circuitry.

The terminal block (TERMINAL BLOCK#2) output can be used as our battery

terminals. The DC value at this terminal block is adjusted using the on-board

variable resistor on the DC-DC booster.

Step 3: The Digital Display

THE DIGITAL DISPLAY:

This is one of my favorite characteristics of this circuit. The 0-20v digital digital

display is easy to use, and will act to show us both the capacitor charge voltage

and the DC-DC booster output voltage. This circuit requires roughly 8-14VDC to

operate. Both of the bottom pins are connected to the ground line. The upper left

pin is the DIGITAL DIISPLAY REFERENCE. The voltage at this pin will be

(http://cdn.instructables.com/F1G/NUKA/GJQEDDDQ/F1GNUKAGJQEDDDQ.LARGE.jpg)

displayed digitally on the display. The digital display will display any voltage

between 0-20VDC. When the DPDT switch is not connecting the capactor bank

voltage to the booster circuit, the digital display will be displaying the charge on the

capacitor bank. When the DPDT is switched on, the output of the booster will be

displayed. Since the display has a 20v maximum limitation, it is suggested that if

you are going to implement it, that you keep the booster output limited to 20VDC or

under.

The voltage at the upper right pin is the line that powers the entire display. This can

be hooked directly to the input DC voltage line. It will work anywhere from 6.5v to

15, but it is preferred that you use 8-14v. The 0.1uf and 100uf capacitors

that are placed at the DC input are implemented for the sake of protecting

this digital display. When you stop, disengage the DC input charge, this display

will shut off.

OPTION:

If you want, you can add a monotary push switch between the DC-DC booster and

the power line of the digital display. This will enable you to have a look at the output

of the DC-DC booster when you push down and hold the monetary switch by

adding secondary power supply for the display. However, if you choose to go this

route, it is necessary to add a diode into the mix. If you want to go this route, as I

did in the circuit viewed in the video, let me know and I'll include another schematic.

Step 4: The Parts, the Theory, and the Conclusions

THE PARTS:

I can offer a kit that includes the bulk of the parts in the schematic for $90 + $12

shipping. The LM317 kit, the 400f super capracitors, the digital display, and the

DC-DC booster board cost more than $90 in total. If you are looking for parts

singularly, they can be found here:

http://www.electroniclessons.com/ (http://www.electroniclessons.com/)

(http://cdn.instructables.com/FWC/8ZQB/GJQEDDDT/FWC8ZQBGJQEDDDT.LARGE.jpg)

I'll include the following for $90 +$12 for shipping with tracking:

2x 400f 2.7v super capacitors

1x LM317 DIY kit

1x 0-20v Digital display

1x 3.4v-34v DC-DC Booster board

1x DC plug (input and port set)

2x 2.2 Ohm power resistors

2x 1N4001 diodes

1x DPDT switch

1x 0.1uf capacitor

1x 100uf capacitor

****

The Jumpers, terminal blocks, PCB, Input DC source, and SPST switch will

not be included. Send me a message if you are interested. You can also

reach me through http://www.engineeringshock.com

(http://www.engineeringshock.com) and through ebay.

THE THEORY:

Most of the basic circuit theory was covered in the instructable. However, I'll go a

bit further in depth regarding super capacitors. When you place a super capacitor

in series with another super capacitor, you can up the voltage; doubling it, if the

two capacitor voltage values are the same, but you lose capacitance. The formula

for lost capacitance is the same as the parallel resistor formula: 1 [ (1/ C1) + (1

/ C2)] Let's use it in the example of this instructable, where C1 = 400f, and C2 =

400f

Example:

CTotal = 1/[1/ C1) + (1 / C2)]

CTotal = 1/[400) + (1/400)]

CTotal = 1/0.005

CTotal = 200 f

Example#2 (C1 = 3000f @ 2.5v / C2 = 10f @ 2.7fv)

First, add the two voltages. (2.5 + 2.7 = 5.2v) This is your max charging

voltage.

CTotal = 1/[1/ C1) + (1 / C2)]

CTotal = 1/[3000) + (1/10)]

CTotal = 1/0.100

CTotal = 9.97f

The total capacitance is always lower than the lowest capacitance added to the

series string, so beware. Play around with this. A good way to check your

answers is to play with this capacitor

calculator: http://www.electronics2000.co.uk/calc/series-parallel-capacitor-

calculator.php (http://www.electronics2000.co.uk/calc/series-parallel-capacitor-

calculator.php)

When placing capacitors in parallel with one another, you are looking at much

easier calculations. When you place a capacitor in series with another capacitor,

you just add the two capacitances together, and that will be your total capacitance.

The maximum voltage you can charge to is always the lowest value. Let's use three

capacitors in our example:

Example: (C1 = 2.0v @ 10f / C2 = 2.5v @ 100f / C3 = 2.7v @ 1000f)

Max voltage charge is 2.0v (The lowest of the three)

CTotal = C1 + C2 + C3

CTotal = 10f + 100f +1000f

CTotal = 1110f

You can also place strings of sets in series, in parallel with one another for the

sake of compensating for lost capacitances. Let's say we have 9x 2.7v @100f

Post Comment

capacitors. We want a capacitor that is higher than 7VDC and has the most

capacitance possible. If we place three if these 2.7v capacitors in series, we get

8.1v, but the capacitance of the string is only 33.3f. We have 9x of these

capacitors, so if we make three strings of three, and place them in parallel with one

another, we have a capacitor bank that has a value of 8.1v @ 100f. Neat, eh? See

one of my capacitor bank videos here:

There is so much theory that goes into capacitors. If you guys have a specific

question, or perhaps a project idea, I will consider building it and displaying it for

you all, right here on instructables.com.

CONCLUSIONS:

This circuit was a prototype, and I will be using it for years and years to come. I

have a solar panel on my window that allows for me to listen to music using free

energy all day long, and even for a few hours after the sun goes down.

There are two things I'd like to do with my next version. I'd like to create a bank that

employs thousands of farads, has a more advanced charging circuit, and has safe-

charge features that are controlled by a microcontroller that cut off a charge once

the device has reached the proper level of charge.

Super capacitors are the wave of the future, relative to energy storage. I am

always looking for new ways of implementing them into projects. If you have any

questions at all, feel free to ask. PLEASE VOTE FOR THIS INSTRUCTABLE OR

SUBSCRIBE IF YOU LIKE WHAT YOU SEE!

THANKS EVERYONE!

(/member/haseebpk/)

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haseebpk (/member/haseebpk/) says:

what is DC-DC BOOSTER CIRCUIT.????

PLZ SEND DETAILS, WHICH BJT OR FET USED FOR BOOSTER CIRCUIT

cunnr006 (/member/cunnr006/) says:

can this device be altered so that it charges from a 5v solar panel, and produces a

constant output of 5v with a power of 1w, would need to discharge over a period of 24hours

Jean-Valéry Thoraval (/member/Jean-Val%C3%A9ry+Thoraval/) says:

i just heard that the faster you recharge abattery, the faster it will die.

i was interested in super capacitor batteries

to charge lithium batteries fastier until i heard

that, any inputs on that?

Tom Hargrave (/member/Tom+Hargrave/) says:

Interesting project - the only feedback I have

is you need some sort of bleed across thecaps to even out voltage. Series wired caps,

even super caps, will charge & discharge

unevenly leading to uneven voltages across

the caps at full charge. Unless you are verylucky, the difference will continue until the

voltage across one exceeds its rated value.

Then it will break down causing the other to

fail.

scci (/member/scci/) says:

You sacrificed high power for more usability, I personally prefer the high power fast

charging. My charger requires a wall outlet and only works for specific caps andvoltages but it charges in 7 seconds.

ctwistedpair (/member/ctwistedpair/) says:

This is excellent! Do you have a picture of the pcb so I can etch my own board?

jumpjack2 (/member/jumpjack2/) says:

Thanks for the very clear and interesting description.

I have 2 questions: - how can I reach 64V in output? Can I connect in series two boosters, or do I need a

different output component? - how can I reach 100A in output? Can I just mount in parallel a dozen of circuits likethis? (btw, how much current does it support?)

I'm trying to boost my electric scooter by some supercaps: I have 20 supercaps rated

25F/2.7V each. By now I only need a few seconds boost for testing.

Thanks.

dsuprina (/member/dsuprina/) says:

What is the maximum current draw for the Super Capacitor battery? I'd like to use this

circuit (or something similar) as a means to support an approximately 4A 12VDC

(/member/ckarthik/)

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draw. Given the ultra capacitors used, how long could such a load be accommodated

in the event that the primary power source (AC input) is cut? (I'm looking for a shortterm -- as in a few seconds -- of UPS capability here.)

ckarthik (/member/ckarthik/) says:

hi nice work there..

I've a 12 v 5ah battery in my bike.. but it isn't really enough for it.. and gets easilydischarged.. i can't upgrade to a higher capacity because of space constraints.. so i

would like to use these super capacitors to increase the battery capacity so thatcollectively I've 9 or 10ah capacity.. any ideas? circuit diagram? thanks in advance

caranfis (/member/caranfis/) says:

I'm looking for a 12VDC, 3A super-capacitor to power up my device for 60seconds.

Does this circuit provide this amount of energy?

danm_daniel (/member/danm_daniel/) says:

awesome, I'm glad you're part of theinstructables community

wiltshire101 (/member/wiltshire101/) says:

Hi, thanks for the infos. Any idea how to homebrew super capacitor?

wiltshire101

Emiliano Valencia (/member/Emiliano+Valencia/) says:

Actually a DC-DC Boost converter will outputany voltage ABOVE it's input, if you feed it 20

volts, you can't get less than that!

dlongenhagen (/member/dlongenhagen/) says:

hello, the supercapacitor is truly a great thing however without the correct chargingcircuit it is just a large bulky expensive item. i did purchase a cap, just recently, iactually need a circuit which will take low miliamperage and charge these bad boys. if

someone has one let me know. if the guy running "http://www.electroniclessons.com/"would get in touch i would relate more input, as it is truly a experimenter circuit, oh,

did i say I'd pay....dave at njvikings1@msn.com

waterlubber (/member/waterlubber/) in reply to dlongenhagen

Well, for the lower the amperage, thelonger the charge time. I think.

THE FORMULA FOR BATTERIES(only one I know, don't criticize me) is

BATT AMPERAGE / CHARGERAMPERAGE = HOUR CHARGE TIME

gosugenji (/member/gosugenji/) says:

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Could you use something like this to jump start a car?? Just wondering :x

flamekiller (/member/flamekiller/) in reply to gosugenji

This wouldn't be able to provide enoughcurrent to jump-start a car.

vvodking (/member/vvodking/) says:

maybe you should make your dc booster work at lower voltage than 3.4 so you would

be able to connect the supercaps in parallel. Otherwise it is an enormous waste ofcapacity and money.

0_Nvd_0 (/member/0_Nvd_0/) in reply to vvodking

If the voltage from the capacitors'

configuration is higher (series), lesscurrent is drawn.

In parallel, twice the amount of currentis drawn by the booster.

Power = Voltage * Current

Thus, you do not gain anything fromparallel configuration except the factthat equivalent internal resistance

(ESR) is halved. That can help in quickhigh current demands.

The real concern is the efficiency ofthe booster. Capacitors should be

arranged in a configuration to producevoltage at which the efficiency of thebooster is maximum.

fuzzhead (/member/fuzzhead/) in reply to vvodking

If I understood it right, then the energy

stored in an capacitance calculatesthrough the term E = 0.5 * C * U^2.

With the given Caps (400F, 2.7V) andthe two possible configurations thatmeans:

E(parallel) = 0.5 * (400F + 400F) * 2.7

^ 2 = 2916 J

E(serial) = 0.5 * 200F * (2.7V + 2.7V)

^ 2 = 2919 J

So the max. stored Energy is the

same for both configurations. -> Nowaste of money ;D

Correct me if I made a mistake ;)

0_Nvd_0 (/member/0_Nvd_0/) in reply to fuzzhead

You are correct. The configuration does

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not matter. The energy stored is alwaysthe function of capacitance and voltage.

EngineeringShock (/member/EngineeringShock/) (author) in reply tovvodking

I've never heard of a booster circuit that can boost less than 3.4VDC up to a

maximum of 34VDC while sourcing a relatively high current output. If you aretalking about a joule thief of some kind, then yes, you can boost less than avolt, but not up to a relatively high DC voltage, and with an extremely limiting

current output.

If you can point me to a booster circuit that can do what you're saying, then by

all means let me know about it and I'll surely implement it.

As well, the user does not have to use two 400f caps in series. They can use2x 3000f caps in series, or slightly modify the power supply charger to workwith a 12v capacitor bank.

Regardless, I've already saved about $50 in the past several months on

batteries, so it really isn't fair to suggest that it is a waste of money, especiallysince super capacitors last one hell of a lot longer than batteries if treatedwell.

dunnos (/member/dunnos/) says:

So... Should I be able to convert Farads to Ah or is that completely wrong? How long

am I able to draw how high a currents from this? It's confusing but really seems verymuch fun :)

Also, how long would these have to charge?

0_Nvd_0 (/member/0_Nvd_0/) in reply to dunnos

Super capacitor vs batterycomparison:

(5 * "Capacitance" * "Voltage") / 36 =

Battery rating in mAh at "Voltage"

I deduced it based on the energy

equivalence of the two reservoirs.

Hopefully, it is correct.

sparky3489 (/member/sparky3489/) says:

SPDT = Single Pole, Double Throw - not Pull

aaa3a (/member/aaa3a/) says:

where can i get this kind of super capacitors from junk boards as i don't need to buy iti searched in atx power supply but no luck could u tell me which boards or devices

should i searching in

regards

valveman (/member/valveman/) in reply to aaa3a

You can't get these caps from junk

boards. You won't find any cap near this

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capacity in any junk/atx power supplies.They are specialized caps. You need to

buy them new.

Look on Ebay

Aperture Laboratories (/member/Aperture+Laboratories/) says:

so, you could use a solar panel to charge thecaps, if you wanted to? ?right?

Inducktion (/member/Inducktion/) says:

You actually don't need a microcontroller or anything fancy to make it turn off

everything once it's all full.

All you need is an op amp, resistors, and a switch of some sort, be it a mosfet, relay,

or even a BJT.

JRL_J (/member/JRL_J/) says:

does the kit come with a charger for the super capacitors?

swimfan2489 (/member/swimfan2489/) says:

great instructable here! from what i gather here, are you basically usingsupercapacitors to completely replace your "battery" source? I am looking to make

something similar to this, it is a mini solar powered (4V @ 50mA cell) USB rechargerfor electronics but I want there to only be supercapacitors so this project is as "green"

as possible.. would it be possible to just use supercaps for this application??

tinker234 (/member/tinker234/) says:

so what could it power

BC-45 (/member/BC-45/) says:

how long does the charge last for?

Confounded Machine (/member/Confounded+Machine/) says:

Very interesting concept. I can see how thecost adds up, I've been working with some

100F super caps...not expensive but notcheap either. The surge capacity of thesebeasts is comparison to their weight and size

is unreal! I may just have to cobble togetheryour circuit.

Thanks

EngineeringShock (/member/EngineeringShock/) (author) in reply toConfounded Machine

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Post Comment

Hey Thanks for the comment. If you have 4x 100f 2.7v super caps, you can do the

same thing = ) Yeah, the great thing about super caps is that they're not goingto shock you. However, I have given myself a rather severe burn after

accidentally shorting the leads on my 96F 12.5V bank =( It set the insulationon my wires on fire. If you're interested, I have another instructables comingout today. If you're interested, check out my profile later on.

Thanks =) Pat

jam BD (/member/jam+BD/) says:

Very interesting idea. Nice project but the $90 price tag is deterring.The digital meter was a nice touch.

cypherf0x (/member/cypherf0x/) in reply to jam BD

You can get the supercaps cheap atgoldmine electric.

EngineeringShock (/member/EngineeringShock/) (author) in reply to jam BD

Hi Thanks for the comment =) Yes, $90is not cheap, but you really get yourmoney's worth. As well, 400f super

caps are not cheap. If someonewanted, They could use smaller caps,but the charge wouldn't last as long.

Thanks again =) Pat

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