Are the 2600f 2.5v capacitors dangerous

[Horryhop]

By dangerous mean if I touched both terminals when it is fully charged. Also is there any project ideas with these capacitors you can think of. Thanks rich

[Simon]

You have answered your own question. The capacitor is 2.5 V, can 2.5 V harm you? If it can I suggest you put down all the batteries you've ever touched very carefully. It is the voltage stored in a device which is lethal as it will drive the lethal amount of current that can harm you. No idea what to do with them though put them in series I news mother battery someone did that for his car.

[wblock]

Please show pictures.  A 2600 Farad capacitor is going to be pretty big.

[MK14]

By dangerous mean if I touched both terminals when it is fully charged. Also is there any project ideas with these capacitors you can think of. Thanks rich

Be careful, because if they get short circuited (e.g. accidentally), by say metal. It can very rapidly reach potentially dangerous temperatures.

Please show pictures.  A 2600 Farad capacitor is going to be pretty big.

It depends what you mean by big. If by big, you mean somewhat small, then yes. (Joke).

Ultracapacitors.



I guess they are fairly big and chunky:

[wraper]

You have answered your own question. The capacitor is 2.5 V, can 2.5 V harm you? If it can I suggest you put down all the batteries you've ever touched very carefully. It is the voltage stored in a device which is lethal as it will drive the lethal amount of current that can harm you. No idea what to do with them though put them in series I news mother battery someone did that for his car.

Yes it can be dangerous. Take a piece of wire, and short it while holding the wire in your fingers, wire will melt and insulation will burn into your your fingers.

[Cliff Matthews]

Please show pictures.  A 2600 Farad capacitor is going to be pretty big.

Here's all you need.. Maybe you meant ultra cap? (there is a difference, the type mentioned is likely a supercap for micro power backup).
http://www.farnell.com/datasheets/1640983.pdf

[wraper]

Please show pictures.  A 2600 Farad capacitor is going to be pretty big.

Here's all you need.. Maybe you meant ultra cap? (there is a difference, the type mentioned is likely a supercap for micro power backup).
http://www.farnell.com/datasheets/1640983.pdf

Have you ever seen 2600F backup supercap??? Max capacitance in that datasheet is 26 times smaller.

[vk6zgo]

By dangerous mean if I touched both terminals when it is fully charged. Also is there any project ideas with these capacitors you can think of. Thanks rich

Unless you are a metallic robot--NO!

Please Google for Ohm's Law!

[Shadetreeprops]

By dangerous mean if I touched both terminals when it is fully charged. Also is there any project ideas with these capacitors you can think of. Thanks rich

There was a test on youtube done on this, anything below 40v DC was okay, above that to 50v was painful, and anything past that dangerous. that was a constant current too. so a 2.5v might be like a static pop but nothing that will hurt you.

now i have a 600V cap 500uf, that will probally stop a heart. but not that i am willing to ever try that.  also have several 400v caps that i rescued from a dumpster, i gave them a lovely home on my parts shelf, they are comfy, and well taken care of, those poor caps were just left out in the cold..poor poor stray caps.

[uncle_bob]

Hi

One of the most basic questions:

If you short out your 2600F cap does it self destruct?

A lot of these parts are long on hype and quite short on actual specs. The Maxwell web site lists zillions of "applications" and very few things that show the real performance of their latest parts.

You don't have to have the TV on for long before somebody will have pictures of exploding lithium cells burning down major cities and significant fractions of continents  The energy density in some caps is also quite high ...

Bob

[tautech]

No idea what to do with them though put them in series I news mother battery someone did that for his car.

Simon, did you mean member Psi?
https://www.eevblog.com/forum/chat/i-didn't-realise-supercaps-worked-this-well/msg440964/#msg440964

[Cliff Matthews]

Please show pictures.  A 2600 Farad capacitor is going to be pretty big.

Here's all you need.. Maybe you meant ultra cap? (there is a difference, the type mentioned is likely a supercap for micro power backup).
http://www.farnell.com/datasheets/1640983.pdf

Have you ever seen 2600F backup supercap??? Max capacitance in that datasheet is 26 times smaller.

Now I have.. I hadn't looked into that stuff in a while. He used a lower-case f so it sent me off thinking about stuff like this 

[vk6zgo]

By dangerous mean if I touched both terminals when it is fully charged. Also is there any project ideas with these capacitors you can think of. Thanks rich

There was a test on youtube done on this, anything below 40v DC was okay, above that to 50v was painful, and anything past that dangerous. that was a constant current too. so a 2.5v might be like a static pop but nothing that will hurt you.

now i have a 600V cap 500uf, that will probally stop a heart. but not that i am willing to ever try that.  also have several 400v caps that i rescued from a dumpster, i gave them a lovely home on my parts shelf, they are comfy, and well taken care of, those poor caps were just left out in the cold..poor poor stray caps.

No,2.5 volts will feel like nothing at all!
The current capacity of a device or circuit has no effect upon the current through you it can cause,if the voltage is insufficient to produce a dangerous,or sometimes,even a perceptible,current.----Ohm's Law again!
Voltage is the determining factor.*

Touch both terminals of a fully charged 12v car battery (a device with a massive current capacity) on a cool,dry day,& it will feel exactly like a fully discharged car battery on a cool,dry day.
If it is hot,& you are sweating,12v will give you a very slight stinging sensation,if you contact both terminals with a sweaty part of your body--most commonly your forearm.

*Sort of,but not quite an exception!
In some circumstances a high voltage supply designed to operate with an extremely low current draw,may have such poor voltage regulation that you will get an initial "zap" falling off rapidly to nothing.
It is always best to assume that WON'T happen!

[Horryhop]

Well thanks very much for all of the reponses, although i will rephrase my second question, being  'is there any projects i can do that have a variable that can be changed'. Thanks for the replies so far rich

[Richard Crowley]

A 2600F capacitor (or array of capacitors) would be as big as a bread-box.
I seriously doubt that anybody makes a 2600F capacitor.
It might easily be mistaken for a battery.

I don't understand what you mean by...
"projects i can do that have a variable that can be changed"
Essentially ANY project has variables that can be changed.
You want to narrow that down to something practical?

[Brumby]

A 2600F capacitor (or array of capacitors) would be as big as a bread-box.
I seriously doubt that anybody makes a 2600F capacitor.

You should check out the capacitor labelling in this video - as well as the maths occuring at around the 35 second mark....

[Dago]

http://www.maxwell.com/products/ultracapacitors/k2-2-85-series

[tszaboo]

A 2600F capacitor (or array of capacitors) would be as big as a bread-box.
I seriously doubt that anybody makes a 2600F capacitor.
It might easily be mistaken for a battery.

I don't understand what you mean by...
"projects i can do that have a variable that can be changed"
Essentially ANY project has variables that can be changed.
You want to narrow that down to something practical?

They sell it on Digikey...

It is used for regen braking and such. China wants to run buses with them (not serial, the big thing on the street). You can probably build a coilgun with a lot of those, and get arrested. Anything where thousands of amps is required for a short time.
These have less than 1mOhm ESR, so 5000A from it is very possible.

[Zero999]

There was a test on youtube done on this, anything below 40v DC was okay, above that to 50v was painful, and anything past that dangerous.

People have different sensitivities to electric shock. There's a 75VDC PSU where I work and I can touch it without feeling a thing. If I'm very sweaty I may get the odd tingle but nothing really bad.

It also depends on the path of current. Touching a 1000uF capacitor charged to 600V with one hand won't kill you but it will give you a nasty shock and a severe burn, but touching the cathode with one hand and the anode with the other could kill.

The capacitance is also a factor. A 100pF capacitor charged to 10kV may give you a shock but it will be only as bad as a static shock received when touching a metal door knob, after walking on a wool carpet wearing rubber shoes.

[Richard Crowley]

It would be virtually impossible to get anything that could be described as a "shock" from such a very low voltage.
That is because of the rather high resistance of your outer skin layer (of dead cells).
Even if you had soaked your hands in salt-water (to make them more conductive) is it unlikely that you could even perceive 2.5V
It takes considerably higher voltage to make it into your body.

However, if you had electrodes implanted into your heart or your brain, 2.5V could be very significant. That is much higher than the normal "signal levels" that our nervous system operates at.

OTOH, if you had something metal/conductive in your hand and you touched against the terminals of something with a lot of power behind it (such as a battery or a very large capacitor) then there would be danger from thermal burns as the metal conducts and turns into a heating element. There are many stories of wrenches and screwdrivers, etc. being thrown across the room from accidental contact to a large capacity battery (even like the ones used in automobiles).  For THIS reason a very large value capacitor is just as dangerous as a battery as a source of accidental heat/spark source around flammable materials.

These kinds of capacitors are typically used in applications where you need high current power, but only for a short period of time. For example for short-term backup to a critical circuit while the main power source is changed (like while changing the battery). Or even perhaps weight-sensitive applications like quad-copters which use high-current but can't handle power sources that weigh very much.

[mikeselectricstuff]

The only hazard is burns.fire if shorted.
I had  a play with a 3kF one : https://youtu.be/mY2X-ZQpnvY?t=1687

[tszaboo]

A 2600F capacitor (or array of capacitors) would be as big as a bread-box.
I seriously doubt that anybody makes a 2600F capacitor.

few hours later...

These kinds of capacitors are typically used in applications where you need high current power, but only for a short period of time. For example for short-term backup to a critical circuit while the main power source is changed (like while changing the battery). Or even perhaps weight-sensitive applications like quad-copters which use high-current but can't handle power sources that weigh very much.

Seriously?
Are multiple people using your login?

[Richard Crowley]

Seriously? Are multiple people using your login? 

Recommend avoiding posting while seriously sleep-deprived from travelling for 24 hours.

[tszaboo]

Seriously? Are multiple people using your login? 

Recommend avoiding posting while seriously sleep-deprived from travelling for 24 hours.

Happens to the best of us 
And that is why we have version control!

[station240]

It is used for regen braking and such. China wants to run buses with them (not serial, the big thing on the street).

They actually built buses, granted they get recharged along the route.

https://en.wikipedia.org/wiki/Capa_vehicle

China are using their own brand of ultra capacitor in these buses, I can't seem to find the reference to what brand it is today.
Of course being chinese build quality on the entire bus, you get things like this.
http://www.greencarreports.com/news/1063473_chinese-electric-bus-catches-fire-on-road-not-the-first-one
That blackened box that's been ripped open is one of the 4 super capacitor banks.