me-bike/escooter upgrade

I am planning on modifying my me-bike, appears to be cheap Chinese's electrical scooter. Picked it up off the side of the road for free!

Specs:
me-bike Classic
Dimension: 1600 x 630 x 1230
Motor: Brushless
Power: 200W with PedalLead Acid
Battery: 48V12AH Charger: 48V1.8A
Max load: 150kg
Max Speed: 25km/h
Range: 40-50km
Charging Time: 3-6h
Tire: 16 X 2.5
Brake system: F & R drum
Extras: Alarm system with two remote controllers

Planned upgrade:
Motor: Brushless non-geared 72v 2000w hub motor https://a.aliexpress.com/_mKfKWQb
Battery: Samsung Lithium battery 72v 20ah https://a.aliexpress.com/_mqSZj6f
Controller: 72v 50ah 2000w https://a.aliexpress.com/_mOuZm9Z

A few questions, do I need a more powerful controller? Will the controller be compatible with my current key ignition, throttle, lights etc
What speed would I be expecting from this build? I live in a hilly town.
Will the drum brake system be efficient?

https://www.manualslib.com/manual/875765/Me-Bike-2014-Classic.html

Your pics won't load for me, must be pretty high resolution. The page keeps the size down so extra pixels only make it more difficult. But there's the manual for those who think they need more info.

So I think your controller is probably fine, if you want bigger it couldn't hurt, but I hardly think you'll use up the motor and controller in this configuration. The brakes are another matter, barely enough on the 200w bike and now you're going 2000w. I know much the same from the Currie, the Voy Electra, the Razor Pocket Mod. Do something about the brakes. One offering: https://endless-sphere.com/forums/viewtopic.php?f=6&t=110311#p1616566

Also, any questions of 'How is this REALLY going to fit?' you have to answer for us. You have the bike and the parts, we don't. A few people may have something that looks similar and offers ideas, but you probably will have to tell us your problems first.

Thanks for the advice, in that case i might look at a 3000w QS motor with disk breaks.

Nice score on that Me-Bike.


Rick