MikeFairbanks
100 kW
I want this to top out at about 8mph but have a lot of Torque. I have the standard ebike kit with a 9c and a 22 amp controller. What would you recommend in an SLA setup? I want simple and cheap. Car battery?
How do I make this slow and strong?
- Thread starter MikeFairbanks
- Start date
nebriancent
100 W
i would need a little more info on the motor
but i would say 24v eg. 2 sla batteries in series should give you your desired speed with most motors
but do be advised amperage is what will give you the torque you want
other options would be a geared motor or a mid drive motor
LFP has a lot of exp in the mid drive motor setups .. and he seems to swear by them
nice thing with this approach is you can keep your battery amps lower , raise your voltage , and gear you chain drive differently to give you a very efficient setup
or course you will lose some efficiancy in the chain or belt but it should be minimal
but i would say 24v eg. 2 sla batteries in series should give you your desired speed with most motors
but do be advised amperage is what will give you the torque you want
other options would be a geared motor or a mid drive motor
LFP has a lot of exp in the mid drive motor setups .. and he seems to swear by them
nice thing with this approach is you can keep your battery amps lower , raise your voltage , and gear you chain drive differently to give you a very efficient setup
or course you will lose some efficiancy in the chain or belt but it should be minimal
nebriancent
100 W
in conclusion
slow- lower voltage
torque - higher amperage than your controller can deliver
slow- lower voltage
torque - higher amperage than your controller can deliver
MikeFairbanks
100 kW
Hmmm, any suggestions on a local supplier that is common in most cities to get a controller that would work with a 9C hub motor?
John in CR
100 TW
The only solution for slow and powerful is to gear it down. Much smaller wheel or as mid-drive with a 2.5 to 1 or greater gear reduction. Going very low in voltage will lead to horrible efficiency and low power.
MikeFairbanks
100 kW
What about if I put the limiter on (250 watts) and run 3 12-volt, 5ah SLA batteries?
Remember, this is only for flat surface riding inside a building and will be plugged in when not in use (literally, plugged in even while parked in various parts of the building).
Would 36-volt, 5ah SLAs work to move it with a heavy load? I found some really cheap batteries locally.
Remember, this is only for flat surface riding inside a building and will be plugged in when not in use (literally, plugged in even while parked in various parts of the building).
Would 36-volt, 5ah SLAs work to move it with a heavy load? I found some really cheap batteries locally.
Samd
10 MW
Run it as a mid drive and use the gear ratio at rear?
MattyCiii
100 kW
I bought a front wheel, 5 x 12 wound 9c motor awhile back when Methods had a 'rare low kv motor sale'. I bought it for low speed/high torque, which that wind should deliver. But my plans changed and the motor is sitting in the basement. I think it's laced into a 406mm rim, and it is the "front wheel" version vice rear, so it might be a good fit for your application. If you think it would meet your needs, I'd be willing to sell at a "clean out the basement" discount.
dogman dan
1 PW
Jump on that deal Mike. then swap the motor cores so you have the 2812 motor in a 26" wheel. Then sell the 2807 motor in the 20" rim.
It's your only solution. Then it could run only about 12 mph at full 36v speed. Or even slower with the jumper plugged in.
You should be able to get in and out of the deal for no more than shipping will cost you.
It's your only solution. Then it could run only about 12 mph at full 36v speed. Or even slower with the jumper plugged in.
You should be able to get in and out of the deal for no more than shipping will cost you.
John in CR
100 TW
Inside a building is dead flat unless you have some wheelchair ramps. It's not likely that you need the strong part, so 36V programmed for 30% throttle may work fine. If you've got ramps and heavy loads like full filing cabinets or heavy desks on dollies, then you'll have to gear way down. Even Dogman's precious high turn count motors won't cut it except maybe in a 16" rim.
What's the actual use inside the school? I'm sure there are plenty of ways to skin this cat.
What's the actual use inside the school? I'm sure there are plenty of ways to skin this cat.
REdiculous
10 kW
mid-drive and use the highest voltage your controller allows, or just one step under it. You should get 1kw at 48v, iirc, and at 36v you should get about 1HP...
I'd look for a deal on SLAs in the 18-20ah size. The more common 12ah size is probably too small if you want real power from just a few/four. Car batteries are out, imo, since you'd need 4 to reach 48v and that's probably gonna be heftier than SLAs.
I'd look for a deal on SLAs in the 18-20ah size. The more common 12ah size is probably too small if you want real power from just a few/four. Car batteries are out, imo, since you'd need 4 to reach 48v and that's probably gonna be heftier than SLAs.
dogman dan
1 PW
Still think a slow wind motor would do the trick. 800w should be plenty of power. I wasn't recomending it for moving the piano, just a guy and the mop or whatever.
Obviously a mid drive can do more, but a slow wind hubbie that is BEING OFFERED CHEAP sounds like a solution to me. Recover all but your shipping cost by reselling the fast hub.
Obviously a mid drive can do more, but a slow wind hubbie that is BEING OFFERED CHEAP sounds like a solution to me. Recover all but your shipping cost by reselling the fast hub.
REdiculous
10 kW
dogman's probably right and if you need someone to buy the "spare", count me interested. :wink:
MikeFairbanks
100 kW
I'd love to do a slow wind motor, but I don't have a clue as to what that actually means in terms of performance. I get the basic idea that it has more torque and less speed, but let's say I hook it up to a 36-volt, 12ah setup. What kind of top speed would it have? I don't mind it going above 8-10, but I'd be much happier with a very strong 15 than a weak 24mph.
dogman dan
1 PW
Not more torque. But you can have the same torque, without having the need to keep the motor turning as fast. So it tolerates a bigger load at a slower top speed, similar to a smaller wheel. The fast motor at the same slow speed will get hot if it's loaded up a lot. People call it more torque because it feels that way to the rider. But it's the same torque, if not even less due to differences in the copper fill.
Bottom line, with a 2812 front motor on that trike, you'd have all of the same power you had before, but your top speed of 12 mph or so means you have much much much more controll over the bike in situations where slow speeds are used. The Fast motor can be ridden slow on the flat of course, but you have to really watch your throttle hand to not overspeed in a tight spot. Since your top speed is so slow, you'd also get better range out of any cheap battery. Cruising wattage would be less than 300 at full speed.
As a bonus, if you did try to tow that piano, it would not melt as fast.
Really, the slow wind motor is merely a substitute for using a smaller rim. So you can keep the 26" wheel meaning you still have a front brake, but still get a slow top speed with good hill climbing performance.
Bottom line, with a 2812 front motor on that trike, you'd have all of the same power you had before, but your top speed of 12 mph or so means you have much much much more controll over the bike in situations where slow speeds are used. The Fast motor can be ridden slow on the flat of course, but you have to really watch your throttle hand to not overspeed in a tight spot. Since your top speed is so slow, you'd also get better range out of any cheap battery. Cruising wattage would be less than 300 at full speed.
As a bonus, if you did try to tow that piano, it would not melt as fast.
Really, the slow wind motor is merely a substitute for using a smaller rim. So you can keep the 26" wheel meaning you still have a front brake, but still get a slow top speed with good hill climbing performance.
