This is a total newbie question, I spent some days reading the forums (this is an excellent site btw), but still need help starting out. I plan to convert a schwinn Meridian trike to electric. I live on a large campus that has hilly grass so I need some power to get around. Also, I will have a small 2-wheel trailer that I will be pulling with a small load.
It seems that the hub motors are very popular, but for my situation (needed to pull weight, and needing more power) is this a good choice. Can I do a hub motor on each of the rear wheels powered by one controller? Also, I am seeing a huge discrepancy in prices for the same wattage of motor, I can find 1000w 48v motors for $135, and then their are (apparently) much smaller motors for 3 times that price. What are the other aspects of the motor I need to look at besides the watts and volts?
Thanks very much.
I would advise at least 3,000 watts, or about 3 1/2 horsepower, as a minimum for what you descrbe, assuming a spped of perhaps 20 to 30 mph is adequate, and the hills are not too steep. It will NOT be very CHEAP to do correctly! (Personally, I would use two "ETEK" brushless motors, with a 72 volt, Lithium battery.(Probably about 4 or 5 thousand dollars, for batteries, motors, and controller/charger) One motor of this type will do, if you are not too heavy, and the trailer load is very light/easy to pull uphill. 60 AH or better batteries are advisable, for good range and service.-Bob
Robert M. Curry
Bob, methinks what you're suggesting is overkill. There's a guy that lives down the street from me, has a three wheel trike motorcycle powered by two etek's one for each rear wheel, and it's a full size motorcycle using car tires, a big frame, a big solar panel array as a canopy, etc. That's what two etek's can do, and that's far more than (I think) is required for an adult trike like he describes.
I haul a small trailer with my bicycle all the time. The motor is an old 36v brushed wilderness energy that has very modest power but then I don't have any hills anywhere nearby. Speed with that setup is generally 15 miles/hr and I don't notice the trailer usually ...
Of course having grassy hills would require more than power than a modest motor like the one on my bicycle. I just offered that as an example. I wonder if one of the 5000 series crystalyte motors @ 72v would be enough?
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Thanks, I was afraid it would be crazy expensive like that, which I cannot afford at this time. It is possible for me to cannibalize a 97 golf cart that is not running because of dead batteries which has a 36v motor and a Curtis controller. Do you think that might be workable?
Thanks reikiman, what about this motor and controller combo, do you think this would give me enough power?
http://www.cloudelectric.com/product_p/mo-me-0708.htm
http://www.cloudelectric.com/product_p/co-axe4834.htm
Yes, if speed is not important, the golfcart motor, suitably geared, and driving BOTH rear wheels should be good for perhaps 15 mph. 60 AH or greater, 36 to 48 volt lithium batteries would be good. Tall grass and skinny tires is not a good combination, especially pulling a trailer uphill!--Bob
Robert M. Curry
That's the same or better as the etek (despite the name difference). Yes that would have the power.
Thinking about this again, climbing grassy hills obviously requires more power than I'm accustomed to where all my riding is on streets.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Thanks Bob,
I'm going to try it with 1 of the mars brushed motor I have linked and see how it goes.
Properly geared, that motor/controller should do the job, if you gear it for low speed. (Perhaps 20-30mph max)--If geared higher, current draw on the uphill climb will be very high!-In any case, do not skimp on amper-hour rating of the battery, use minimum of 60 AH lithium. (100 AH lead-acid would work, but weight & size is too high, especially for hillclimbing with a trailer and skinny tires on grass!)-Bob Curry
Robert M. Curry