Capacitors

[NitroVal]

What does adding extra capacitors do for the ESC? Any downsides to addkng more?

[Ub Hauled]

no downside in adding more, unless you think using more space a down side.
they serve to "equalize" the voltage spikes in the ESC, they keep it more consistent.
It really helps.

[NitroVal]

Do they increase the current iutput at all or allow you to run more cells?
How hard are they to install?

[Ub Hauled]

do not increase the input, do not allow for more cells...
they are easy to install...

they charge up and hold voltage when you hook the main cells.
They will always do that... think of it kinda like a camera's flash, but constant instead of one burst.
They keep charging over and over once the ESC demands the power that's stored in them.

[G Doggett]

Simple explanation - they soak up the voltage spikes that can damage you ESC and motor.
Graham.

[NitroVal]

Ok, so the sole purpose they serve is safety

[Ub Hauled]

Simple explanation - they soak up the voltage spikes that can damage you ESC and motor.
Graham.

Bingo.... thanks...

[Ub Hauled]

Ok, so the sole purpose they serve is safety

safety of your equipment and ultimately you.

[domwilson]

What does adding extra capacitors do for the ESC? Any downsides to addkng more?

They do a number of things.
They are for power conditioning. Minimizing or removing ripple from the power source under high current demands.
In addition, with capacitors in parallel, they increase the filter capacitance of the ESC and lower the ESR (Equivalent Series Resistance).
simplified, in the ESC's circuit, think of them as little reservoirs of electricity. Too much capacitance can be detrimental as it may take too long for the capacitors to charge up.
This can be damaging to your batteries as well as some ESC designs.

[mickvk]

I'll take a shot at putting it in layman's terms as I understand it. When you punch the throttle, there's obviously a spike in demand or draw. That causes a dip in voltage. If the dip is severe, it could cause a ripple and that could cause the ESC to fail.

A capacitor is used to help prevent this. The capacitor "fills" at battery pack speed, but depletes much faster, so it does a good job of handling instantaneous spikes in demand.

The same implementation is done for car stereo amplifiers. It allows the battery to supply a steady current while a bass notes take instantaneous spikes.

Come to think of it, when I use a CD burner on my computer, the same concept is used. The read and write buffers are small fast areas of memory (like a capacitor) which handles variations from the CD burner's rated speed (like the battery pack discharge limit).

[NitroVal]

So how can you tell you need/dont need them?

[Flying Scotsman]

If the ESC was designed for any other use than a boat. It would be prudent to add them and even then you can not go wrong with adding more to a boat designed ESC. Unless it has been enginered and designed by the Germans!

Douggie