When are little black beer cans needed?

[Wheels007]

I see some ESC's come with those black caps "capacitors?" on the ESC to battery wires. When do you need them and how do you know if you need them?

 

[Jimbobjr]

I see some ESC's come with those black caps "capacitors?" on the ESC to battery wires. When do you need them and how do you know if you need them?

That question is ask and answered many times but I’m convinced know one really knows when they need them or what they do...

 

[Notorious J]

I see some ESC's come with those black caps "capacitors?" on the ESC to battery wires. When do you need them and how do you know if you need them?

Those are mini cap packs. The design is to store a little extra energy to make sure the power supply isn't affected when going hard on the throttle. Most rigs run two fans and a servo, which means the bec (battery eliminator circuit) is being taxed more. The capacitors store a bit of energy so that there's less lag when you squeeze hard on the trigger. Speed runners and drag cars use custom ones to help eliminate that lag, which they refer to as ripple. If it sounds like I know what I'm talking about, I don't. I'm just spewing what I think I read about the whole concept while considering building one of those packs myself.

 

[Engineer]

Capacitors discharge energy very quickly so they can be used to supplement energy when there is a large draw. Car audiophiles have been using “stiffening caps” for years and these are in the 1 Farad range.

The sizes that are used in RC cars don’t store that much energy (to see this, plug in a battery to charge the cap, then unplug the battery and turn on the ESC. You can watch the fan spin for a millisecond before the energy in the cap is depleted) and are meant for only addressing very transient voltage sags.

 

[Notorious J]

Capacitors discharge energy very quickly so they can be used to supplement energy when there is a large draw. Car audiophiles have been using “stiffening caps” for years and these are in the 1 Farad range.

The sizes that are used in RC cars don’t store that much energy (to see this, plug in a battery to charge the cap, then unplug the battery and turn on the ESC. You can watch the fan spin for a millisecond before the energy in the cap is depleted) and are meant for only addressing very transient voltage sags.

What I meant to say

 

[Wheels007]

Cool thanks guys. I've been close to pulling the trigger on an EXB or XTR and was wondering if I would need to solder additional items.