4 ms·
> For example, a capacitor operating at 5 volts will continue to operate at the same voltage even after a decade. But unlike batteries, they cannot discharge en
by guntars 3y ago
> For example, a capacitor operating at 5 volts will continue to operate at the same voltage even after a decade. But unlike batteries, they cannot discharge energy constantly—to power a mobile phone, for example.
What is this nonsense?
- f_devd 3y agoI had to reread it a few times but I think it's just poor phrasing, in the first sentence they are referring to the limited number of recharge cycles of most rechargeable batteries (which is generally much less applicable capacitors). And in the second sentence they are referring to the limited capacity of capacitors.
- hulitu 3y agoIt think they are just rephrasing the famous "Beware of the charged capacitor" /s
- hinkley 3y agoThey’re trying to explain that 1 farad at 1 volt is a watt second. F = W * s / V² AA batteries are around 4 watt hours so that’s somewhere around 6400 farads at 1.5V to do the same work. You need a 7f capacitor just to get within a factor of 1000 of the energy density of an alkaline cell. Ultra caps at present are in that neighborhood. So three orders of magnitude off. Charcoal supercaps are limited to around 2.7 volts, and Maxwell Technologies made a huge deal out of getting their caps from 2.5V to 2.7V. That exponent makes that a 8% increase in voltage but a > 16% increase on power. Nobody mentions the operating voltage of grapheme in this article.