OT: Heated jackets

[John Rumm]

You can't get more energy, but you can get more power since a capacitor will be able to sustain a higher discharge current (for less time).

[John Rumm]

Yup using a 18V power tool battery makes somewhat more sense - more available power, and much faster recharging.

[Chris Green]

Still only the same amount of 'warmth' though, just get it quicker.

[Paul]

For that, you want the Ultracapacitor.

One of those, with quite fat tabbed leads, was rated at 3000A peak discharge.

Good for arc welding itself to your discharge stick, and not letting go.

The number of joules is still fixed by the capacitance value.

A typical Supercapacitor, you can draw 0.5A for one minute. The current flow has a limitation, and the discharge time is longer as a result. Not a good candidate for welding say. Still a good candidate, for running a LED light source for a very short time.

And relatively speaking, expensive for what you're getting. Maybe a Lithium battery would be a better buy for some uses.

But if you need to do "burnouts" with your BEV, then the Ultracap is the one to have. A bank of those to withstand the voltage, and an equalizer network to make sure the voltage on each cap is roughly equal (series wired). The WVDC tends to be relatively low, and for logic applications, you might need two Supercaps in series to get enough voltage.

This is why Supercaps are sometimes used with boost converters, so a 2.7V Supercap can run a 5V circuit. The concept of "boosting" is shown here. The benefit of running devices off a single cell, is it makes it easier to control the voltage on them. If you used a single Supercap for this example, then there'd be no equalizer concerns. And all you've have to do, is ensure the boost could never draw more than the "rated current" of the cap.

With an Ultracap in the same circuit, you would never have to worry about exceeding the current spec. If something shorted, the Ultracap would just vaporized it for you :-) A good time to be using the 30 gauge wirewrap wire.

And I've not seen any comments regarding failure modes on those. But for the same money, you could buy quite a few 18650s.

They left room inside some of the early SSDs for a Supercap. And then didn't solder one in. Neither did they include the boost components (so soldering in the Supercap was not the whole story).

There's a real good chance some Lithium goodness would be better suited to heating.

Paul

[RayL12]

Something I have looked into doing for a while but not bothered...

Carbon fibre heater. A ribbon of carbon that will reach 50C @ 12V per mtr length at very little cost. The carbon tape being the only(washable) element in the circuit.

Ray.

[Vir Campestris]

Just search for "capacitor" and "conductor" in the text I quoted.

Andy