Every trace on a circuit board is a cap, a resistor, and an inductor. Every wire is a cap, a resistor, and an inductor. Every motor is a cap a resistor and an inductor. Every battery is a cap, a resistor, an ionic impedance, and an inductor.
1F at pack voltage is a massive amount of capacitance, as every time you double the number of caps in series the capacitance is halved. If you start with a 10F 2.7v cap, but the time you have 10 in series to make a 27v cap it's a 1F cap.
I appreciate your input and post count means nothing here, only content. In my job designing EV and grid batteries, that capacitance which seems insignificant from an energy storage perspective still has a massive influence in cell behavior during transient charge/discharge rise times. Resistance and impedance of the cells and interconnects determines thermal loading. Cell inductance and bussing/interconnect geometry, and isolated case capacitance determines the radiated EMF. If I neglected these other aspects which a cell also happens to be along with an electrochemical storage device, my designs would not reflect/simulate real pack attributes and behavior needed for success. For these reasons the capacitance of the cell (as well as resistance, impedance, and inductance) are all real and critical aspects of the cell. This same extent of detail is required in high power EE where it's critical to model/measure every PCB trace's inductance, capacitance, impedance, and resistance to accurately simulate current rise times to understand how optimize switching speeds for current control and shoot-through avoidance deadband (or synchronous rectification timing if you're getting fancy with a controller).
weber wrote: ↑
Apr 26, 2018 4:05 am
liveforphysics wrote: ↑
Apr 26, 2018 3:41 am
That said, having 1F (or any amount of capacitive storage) does still make it a capacitor that gets recharged by an electrochemical process.
I know I've only made 2 posts to this forum and you've made a zillion. And I don't know anything about you except the posts I've read in this thread. And your handle "live for physics" makes you sound like my kinda guy. But if you insist that anything that has capacitance
is a capacitor
, then I'll just trust that everyone else can see the problem with this, and I won't bother arguing any further.
But I will say, my main concern with this is to reduce the suffering caused when people are induced to part with their hard earned cash on the basis of grossly inflated claims, and you're really not helping.
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