Unfortunately it's not possible to answer any of your questions except one, as there is not enough information. But you can answer most of them with at least guesstimates, using information you may have or can get; thoughts and questions to ask yourself are listed below. If you consider all the questions and information and post it here in detail, we can help you get any answers you don't find after that.
Hey guys,
I want to start a e bike project and I found a electric motor (36v, 800w and spins at 2750 rpm) is that enough?
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And what Kind of battery would you recommend for that motor or would you recommend a stronger motor?
Enough for what specific job (speed, total weight, range, acceleration, etc), under what specific riding conditions (road/path type, wind, slopes/hills, etc)?
To find out what power you need, define those things as well as you can, then go to simulators / calculators like the motor and trip simulators at
Home page , and use the information to guesstimate the worst-case power usage (watts) you have to determine what size/kind motor and controller and battery you need, and the worst-case capacity requirements (wh/km) to determine a minimum capacity for the battery for the range you require.
And how fast would it be?
How big is the wheel it will drive? What is the gear ratio between them? What RPM will the motor spin at with the battery voltage and controller? (need motor kV or RPM/volt, can be guessed with listed RPM / battery voltage x 0.8 (80%))
Another question that I have is that in the listing it says in has a rated current of 29A, what does that mean?
Motor current rating means that it will draw that current from the controller at max allowable motor load at full RPM at the rated battery voltage. If it's loaded down so it can't spin as fast as it should, it will draw more current and heat up more than it should (enough overload will overheat and damage it). At lower loads it will draw less current. The simulators can show you how this works, with some experimentation. (there are instructions on the simulator page for how to use it).
