While I have been flying CL for 60 years, I have never, until now, gotten much interest in Electric power. Recently I have because of concerns over noise complaints (I fly near a residential area) and I have seen a couple electrics that really got me thinking.
So here it is - explain it to me like a five-year-old - I want to know how an electric motor relates to a glow engine (ie. a 2820 is equal to a .40), how to determine the best battery packs, and any other information that a complete newbie should know so that he doesn't get discouraged and go back to glow.
I realize that I am asking a lot and you might not have time (or patience) to explain everything so I will let you know that I am not afraid to read about it from a good book or website that you may know of.
I am OK with people telling me you need a XXX motor and a 150 milliamp battery, but I would like to know the whys along with the whats...
My first electric is a Magician from Pat Johnston. It is just getting started on the workbench now.
Thanks for your time - Eddie
I too flew IC for 60 years and 2020 will be my third 100% Electric.
I have found that it is the prop that pulls the plane both IC and electric. Pitch, diameter and RPM determine how much thrust the motor/engine is going to give you. This is how an electric relates to an IC. If you are powering a 40 size ship with a 10-6 at 9,500 rpm chances are good that any electric motor that can duplicate that will be fine. RPM's come from the kv rating x the voltage. So, if you buy a motor that will run on a 3,4,5 or 6 cell battery you really have a .25, .46 and .60 capable size motor in one electric. Don't get bogged down in the numbers at first. On your first one go with what someone else has used for that plane. Others have already suggested that but hearing it twice is not too much. Trust me, there are enough things to do wrong at first to occupy your attention for a while. I can't emphasize enough how quickly a simple mistake in hooking up a system can wipe out everything. Good news is that they make really great dummy parts for building.
It won't take long to form the habits that saves your wallet from revolting.
There are many brands of motors out there and they can get expensive. A favorite that is also good enough for competition is the Cobra line. The 2820/12 is the 46LA of the electric world. Pick your timer next then get the ESC that works best with it. Again for starters you can't beat Hubin and Castle, like the Cobra they are not top of the line but are good enough for competition.
This is just a personal observation and probably based on good luck instead of careful planning. Batteries are a mystery at first. So many sizes and unlike fuel that you can add some caster or nitro for the day, they are what they are and cant be tweaked. everybody is going to tell you that you need about 30% left on a battery after the pattern. Good luck finding one light enough that will do that. I routinely run mine down to 5% with no problems. It is not good practice so I don't recommend doing it but, if the plane is so nose heavy that you can't do a decent pattern what is the point. I use Turnegy and Zippy which cost about 30% of what you would pay for Thunderpower. (I have purchases a set of 4 5s 3000's for as little as $23 each.) My partners in crime here that use Thunderpower get about 50 cycles before they start crapping out. I am at 60 on my last set of Zippys and they are still marching around like the energizer bunny.
So get something that works, grab some cheap batteries and a few props to play with and put in a couple of hundred flights, monitor battery usage and you will have learned enough to start making informed choices.
Welcome to "The Dark Side"

Ken