oatnet
1 MW
Greetings!
I am new to this hobby, I was messing around with Brushless hub motors from Panterra electic scooters and discovered the bicycle hub motor. I am most of the way through building a standard upright bike using a used 'goldenmotor' front wheel and SLAs and looking forward to lightweight cruising with it.
Meanwhile, I just aquired a used crystalyte 408/4011 dual speed front wheel with a 72v controller and I am thinking about building a hill climber/speed/range machine despite my 250lb mass. My area is dry and sunny year round, my commute to work is only a handful of miles, so I might be able to dump my primary car.
I've done a fair amount of internet research and I'm hoping this community's real-world experience can confirm or correct my conclusions:
I decided to go with 72v to be able to max out RPMs and provide the biggest 'pipe' for current flow.
I decided to go with a single pack, cramming as many ah as I can.
I decided to go with NiCad. As a newbie I am not yet comfortable with Lithium (or the price!) and Nimh doesn't appear to have the cycle life (or durability and price) of NiCad. Nicd seems to be pretty durable and forgiving with a long life cycle. I like being able to drain it dry and overcharge it without damaging the battery (accidents happen); plus if I need high charge/discharge rates I may reduce the pack's cycle life but won't kill it. I know that it isn't as light as Nimh or Lithium, but their weight savings would be a small percentage of rider/bike weight so I am figuring the difference will be minimal. I exepct that it will take a lot of amps to generate the torque to move this heavy bike/rider combo up hills, so the 3c discharge rate on a cheap battery is appealing. The only remaining downside I see to Nicd (for my application) appears to be environmental hazards - but I expect to recycle/dispose of the batteries properly, just like I do with all of my other batteries.
Does this make sense to you experience PEV'rs or am I missing something?
Also, with a dual-speed motor, I figure at lower mph I can run the 4011 winding to max RPM for effeceincy, and for high speeds I have the 408 winding. I know it isn't a Phoenix, but ON PAPER it looks like it covers a broad range of low torque and high RPMs. I have seen postings from people who didn't get the variety they hoped out of the dual-speed motors, but they all seem to be running 36/48v and 20 amps, so I'd expect the motor to be current-starved for both windings - I hope 72v/20a will supply 1440 watts and that will be enough to make a difference, do you folks think it will?
Please let me know what you think!
John
ps - has anyone checked out these 13000mah nicd f-cells on ebay ( Item number: 110108786513)? 8000mah is the highest I've seen elsewhere, 13000 @ 3c would provide almost 40 amps of current and 930 watt-
hours, enough for me to commute for over a week between recharges. They are not tabbed and the seller has no documentation on them, but boy would I like 13000 ah of Nicd in a single pack...
I am new to this hobby, I was messing around with Brushless hub motors from Panterra electic scooters and discovered the bicycle hub motor. I am most of the way through building a standard upright bike using a used 'goldenmotor' front wheel and SLAs and looking forward to lightweight cruising with it.
Meanwhile, I just aquired a used crystalyte 408/4011 dual speed front wheel with a 72v controller and I am thinking about building a hill climber/speed/range machine despite my 250lb mass. My area is dry and sunny year round, my commute to work is only a handful of miles, so I might be able to dump my primary car.
I've done a fair amount of internet research and I'm hoping this community's real-world experience can confirm or correct my conclusions:
I decided to go with 72v to be able to max out RPMs and provide the biggest 'pipe' for current flow.
I decided to go with a single pack, cramming as many ah as I can.
I decided to go with NiCad. As a newbie I am not yet comfortable with Lithium (or the price!) and Nimh doesn't appear to have the cycle life (or durability and price) of NiCad. Nicd seems to be pretty durable and forgiving with a long life cycle. I like being able to drain it dry and overcharge it without damaging the battery (accidents happen); plus if I need high charge/discharge rates I may reduce the pack's cycle life but won't kill it. I know that it isn't as light as Nimh or Lithium, but their weight savings would be a small percentage of rider/bike weight so I am figuring the difference will be minimal. I exepct that it will take a lot of amps to generate the torque to move this heavy bike/rider combo up hills, so the 3c discharge rate on a cheap battery is appealing. The only remaining downside I see to Nicd (for my application) appears to be environmental hazards - but I expect to recycle/dispose of the batteries properly, just like I do with all of my other batteries.
Does this make sense to you experience PEV'rs or am I missing something?
Also, with a dual-speed motor, I figure at lower mph I can run the 4011 winding to max RPM for effeceincy, and for high speeds I have the 408 winding. I know it isn't a Phoenix, but ON PAPER it looks like it covers a broad range of low torque and high RPMs. I have seen postings from people who didn't get the variety they hoped out of the dual-speed motors, but they all seem to be running 36/48v and 20 amps, so I'd expect the motor to be current-starved for both windings - I hope 72v/20a will supply 1440 watts and that will be enough to make a difference, do you folks think it will?
Please let me know what you think!
John
ps - has anyone checked out these 13000mah nicd f-cells on ebay ( Item number: 110108786513)? 8000mah is the highest I've seen elsewhere, 13000 @ 3c would provide almost 40 amps of current and 930 watt-
hours, enough for me to commute for over a week between recharges. They are not tabbed and the seller has no documentation on them, but boy would I like 13000 ah of Nicd in a single pack...
