Basic commuter bike

[Wax]

Hi there. New to the forum with some questions I really can't seem to get / find answers too

I have a 250 watt rear hub motor brushed , 2nd hand but working just fine

I'm trying to build a bike to ride to work with out making a hot rod. I'm sure that will come later

It was originally a 18v engine I'm was thinking about stepping it up to 24v or maybe 36v with a 500watt controller
I was looking at some 10s 4000mah battery.
I am doing a 12 mile round trip to work and home , so I figure I would need at least two to get there and back

Any recommendations as to requirements , am I on the right track here.
Thank you in advance

 

[wesnewell]

Read this.
https://endless-sphere.com/forums/viewtopic.php?f=3&t=66302

 

[Drunkskunk]

Welcome to the forum.

Unlike brushless motors, brushed motors don't take overvolting quite as well. 24 volts is a 33% increase. that should be ok. 36 volts is a 100% increase in voltage. Likely that wouldn't. Adding a 24V 500w controller is adding more than 2.5 times more power to the motor than it was designed for. That might work just fine for a while. However, I wouldn't count on it to work reliably. So if you're looking to have a reliable commuter, this isn't the way to go.


The capacity of battery you stated would be ok if you keep the speed down around 15 mph. That's also about as fast as a 250W motor should go for any distance. Much faster would burn the motor up. But Lipo isn't a safe chemistry. It's also not the cheapest, by the time you include the chargers and monitoring equipment necessary to use it properly.

There are better options.
While this battery is too powerful for your motor, it's an example of a much safer, cheaper, better option, with capacity to get you reliably to work and back at much higher speeds: http://lunacycle.com/batteries/48v-samsung-18650-battery-pack-10ah/ With a basic charger and shipping in the U.S, it's $340 for a 480wh battery.

And since I'm recommending a better battery, another ~$200 on ebay will get you a 500-1000w brushless kit that should be reliable for decades, and more powerful out of the box than the absolute best you could get out of that brushed motor just before it melts.

 

[Wax]

That's awesome and just the answer I wanted
I'm hearing ( and very politely ) don't wast your time with the set up you have lol

Thank you and I will just ebay a kit, I had suspected this may be the case.
I to in another field have to tell people the same sort of thing a lot of the time. This being the case I may get hold of a 48v 1000w system as you don't have to use it all but you sure as heck will not have an issue with hills after this.