Raven505 said:
Hello everyone, I’m going to be building a cruiser for commuting and touring with a bob trailer. I know I’m going to be using a 1500 edge rear hub laced to a 26” rim. I’m wanting more torque then speed.
How much torque? Meaning, what kind of pulling power are you needing, on what kind of terrain, against what kind of winds, with what amount of weight?
If you can go with a winding of that motor that has a higher number, it will have more torque at the same battery voltage as a winding with a lower number. (see http://ebikes.ca/simulator for help understanding, if you need it). (though it will have a slower top speed at that same voltage).
You could be better off with a completely different motor depending on your needs. What is your reason for picking this one?
I’m thinking a 48v 20a battery.
You probably mean 20a
h, as batteries are rated first by capacity (Ah), not current capability (A). You'll want one with more Ah than you need, because as it ages it will deliver less capacity. Determining how much capacity you need will require answers to the above terrain/etc questions, as it can vary widely.
My CrazyBike2 gets about 20-25wh/mile, no pedalling, 20MPH cruising and max, lots of stops and starts, no wind no hills. Same conditions, my SB Cruiser trike takes twice that, around 50wh/mile, so it takes twice as big a battery to go the same distance.
More regular bikes than those could take anything from 10-20wh/mile under the same conditions.
But you will also need a battery that is rated for more *continuous* current (A) than you actually need from it, so it will still be able to sustain that as it ages.
You'll also want a battery from a place you know is reliable (not the cheapest thing you can find on ebay/etc), and that you can take it back to when it has a problem, or else you're going to be fixing it yourself, since replacing it will probably be expensive.
I’m really confused on which controller would be the best fit?
The more torque you want, the more A you want from the controller. But the more A it can provide, the faster it eats your battery under stop/start, hilly, or windy conditions, and the faster it heats up the motor. As long as the motor was meant for this usage, it'll be fine, but if it's too small to shed the excess heat, you'd either have to have a more appropriate motor, or use one of a number of methods to increase cooling of it.
But it does allow you to still do the same acceleration rate you need under any of those conditions, if it's high enough A in the first place.
Sinewave (FOC) controllers are MUCH quieter than trapezoidal (cheapest) types. PUre current (sometiems called torque) throttle controllers are easier to control via throttle than speed/PWM (cheapest) types.
Some have displays and/or are user-programmable to customize them after you get them. Most do not/are not.
The battery continous (not burst) A rating has to match (preferably exceed) that controller A rating.
Watt ratings are irrelevant; nobody rates them the same as anyone else, everyone lies about the ratings or exaggerates them for marketing. Same for batteries, motors, controllers, etc. See http://ebikes.ca Learn page for more info on that. (or many threads around ES).