Do I Need A BEC?

[BrianG]

Originally Posted by hoovhartid

Thanks brian,

I have a few other questions for you...
would adding capacitors help keep heat down on the esc?

similar to what you suggested in here?;
http://www.rc-monster.com/forum/show...=add+capacitor

It may help. It depends on where the heat is coming from. If it's ripple current caused by the motor, then yes. If it's simply the losses from EFT switching/rdson values, then not so much. That said, it won't hurt to add a coupe/few. The worst that'll happen is it doesn't help.

Originally Posted by hoovhartid

if so, could you recommend which ones to use...maybe something like these?
http://www.mouser.com/Search/Product...u7jrHccg%3d%3d

Personally, I like to add about 50% to 100% more capacitance than is already there. Example, the MM has a total of 990uF IIRC. So, I would add between 500-1000uf of capacitance total. More is better, but you don't get as much bang for the buck, plus the physical size gets cumbersome. Also, more caps of smaller value is better, so instead of one 1000uF cap, use three 330uF, or two 470uF caps. Transient response is better and there is more surface area to shed the heat.

Then, pick a voltage at least 25% higher than the highest peak voltage you plan to use. By "peak", I mean use 4.2v/cell for lipos, 1.4v/cell for NiMH, etc.
Up to 4s (16.8v peak), use 25v caps.
Up to 6s (25.2v peak), use 35v caps.
Up to 8s (33.6v peak), use 50v caps.
Over that, 100v is the next common voltage value.

Originally Posted by hoovhartid

also, how is that different from using something like this?;
http://www.horizonhobby.com/Products...ProdID=SPM1600
?

That is not a low-ESR cap. Also, it's only rated for 10v.

Originally Posted by hoovhartid

sorry for so many questions...
thank you in advance

Jarrad

Parts Express has a decent collection of low-ESR caps to choose from.