lauradawn said:
I'm converting to a bike as my main car.
I will be going up quite steep hills daily - in fact possibly a climb of a few thousand feet minimum daily.
Can anyone give some good advice as to where to find an affordable and good conversion kit that would handle this with ease - make it all the way with no need for me to pedal at all going up? (a sign to me it's a good system - one that can make it the full 5000 foot plus climb).
I know it will still be expensive, but would like it closer to $1000 than $2000. Less even better!
You'll need gearing to get the most efficiency out of your motor. Doing this, and you can reduce the amount of battery that you'll need to make the climb. For ready made kits, I'd suggest a cyclone. If you think you're upto the mechanical challenge, you can implement your own chain/belt drive using an external motor such as an RC motor or an Agni, Etek, Mac or Perm.
Is there a particular speed that you desire? Can you give a specific distance? Can you give some specific percentage grades? How heavy do you intend your bike + gear + you to be?
Just as a bit of advice, 5000 ft. of elevation change will entail a lot of energy and battery capacity. With a lot of battery capacity comes a lot of cost. It might make more economic sense to go with a motorcycle, especially since they can go quite a bit faster up hills than "typical" ebike kits and your trip times could be cut drastically, depending on your intended travel distance.
Assuming 300 pounds of total weight, the minimum potential energy to overcome would be...
mass * gravitational constant * height =
136 kg * 9.8 * 1524 meters = 564 watt-hours.
If you're going an average of, say, 15 mph... you have about an estimated 15 watthour / mile due to wind losses, rolling resistance, motor cogging, etc.
So, assuming this is over, say, 10 miles, you have 564 watthour + 15 * 10 = 714 watt-hour expended.
If over 20 miles, you have 564 + 15*20 = 864 watthour expended.
But.... how much do you need from your batteries? That's going to be the above figures divided by the motor system's efficiency. At 80%, you could expect 864/.8 = 1080 watt-hours.
Now, you introduce a certain safety margin that takes into account things you didn't take into account (Such as windy days and rolling hills). I'd say, 50% is a good estimate which would also help with battery longevity. So, now you're at 1080 * 1.5 = 1620 watt-hours. At 50 cents per watthour, you're looking at 1620 * .5 = $810 alone. If you want a ready battery solution such as a 60V 30Ah ping, I believe that runs for $1500 (With shipping).
Now you have the motor and other costs. I'd estimate $200-300 on the resourceful/low side assuming you have a bike available and $1000 on the high "easily available" side (Or if you buy retail bikes, I'd expect something like... $6000 since they seem to have a 300% premium on everything).
So, on the low / resourceful side, I might expect it to cost roughly $1200-$1300. On the easily available side, probably around $2500.
But, on a positive note, if this is to serve as a car replacement, it'll be much cheaper in the long run. However, if it's really a "sunny day" supplement and you take the car on the not-so-good days, then the most you're saving on is gas and mileage-related depreciation. If your car is somewhat old, depreciation is pretty minimal. And, assuming 20 mpg up, then a 20 mile distance would only use roughly a gallon a day which is like 250 work days * 3 = $750 / year. A 40 mpg motorcycle would only cost like $375 / year for gas and I'd imagine motorcycles are significantly better with uphill mileage than cars since they have to propel much less weight up the hill, so I might be underestimating a motorcycle's mileage.