lazarus2405
10 kW
Hello folks! About two months ago I posted a feeler topic here to set me on the right path, and everyone who posted was extremely helpful, informative, and respectful. If only the rest if these here interwebs were so.
Well, I preparing to order my parts within the next two weeks, and I'd like to run everything past the folks in these forums. If you spot any potential problems in my understanding or any room for improvement, by all means speak your collective mind. I've got a lot of questions, so please answer any you can. It'd be a great help to know all I can before placing an order.
The basics: I am starting completely from scratch. The only piece of kit I currently own is a basic steel-frame unsuspended mountain bike, with 15 gears, awful brakes, and 26" wheels with offroad tires.
I plan on running a 5304 motor in a 26" rear wheel at 72v off of 6x12v 18Ah SLA batteries through a 72v 40A controller. I'll be ordering everything I can from ebikes.ca (especially the controller, as I like what I've seen of their customized clyte controllers with plugs for their Cycle Analyst), and what I can't get from there I will be buying off of PowerRideStore (primarily the batteries and electrical connectors).
I'll be connecting everything with Anderson Powerpole connectors so that I can easily remove anything I need, especially the batteries. For charging, I plan on disconnecting all the batteries, reconnecting them in parallel, and using a good 4-stage car battery charger.
I am in the hub motor camp because of its simplicity. I can solder but not weld, so chain systems are out of the question. I'm a university freshman, so this will be my primary form of transportation around campus and around town, but just as importantly it needs to be fun to ride. Do note that I am both young and stupid, which will affect my views on rider comfort and speed, respectively.
For legalities, I plan on keeping a printout of the relevant Federal law (pedals, 750w, 20mph) and using the Cycle Analyst to limit my speed to 20mph and amps to 10 if I ever am somewhere where I feel likely to come under scrutiny... but I plan on finding the bike's limits, on... er... ah... private property... right.
Now, for my questions. If I found an answer, or someone posts one, I'll put it in bold directly following the question.
What gauge wire will I need to wire everything so that I'll have enough headroom for any future changes? I don't want to ever have any issues with my cables not being able to carry peak current.
10 AWG should be fine
I have never soldered things to carry anywhere near this current. Are there any special instructions I need to follow, or perhaps a guide somewhere? I want to do all of this myself, but I also want to do it right.
Make a clean, secure connection. Do not use so much solder that connections will have difficulty fitting into the Anderson casings
As far as I know, Anderson Powerpoles are the best way of making disconnectable high-current DC terminations. Are there better options, or is that the way to go?
They will be more than adequate, and ebikes.ca kit even comes with Anderson connectors on its controllers and motors
I can only seem to find Powerpoles rated for 30A. Can I safely use them? As with the cables, I don't want to have any issues when I push things.
The amperage rating on Powerpoles refers not to what the connection is rated to handle but rather what gauge wire the crimps are designed to accept. The 30A connectors will accept 10 gauge wire.
Would I cause damage by running an even higher voltage? The ebikes.ca site says that their 72V controller will be fine up to 100v, but I'd rather not have to deal with blown MOSFETs.
I talked to Justin at ebikes.ca, and although the capacitors and MOSFETS are rated to 100V, a 96V nominal voltage battery comes off the charger at well over 100V. However, as of 10/23/07, they are expecting a shipment from China in a few days which will include new 72V 50A controllers with MOSFETS with significantly lower resistance (I cannot remember how many miliOhms), which should be easily able to withstand a higher voltage setup.
If not, perhaps would I be better off running, say, 8 batteries with fewer Ah each for 96V and a similar number of watt-hours? Aside from the greater torque and top speed, would using smaller batteries at a higher voltage lead to a lower amp drain and thus be better with respect to Peukert's Law? And would it be more fun?
Running more volts on more batteries with fewer amps and thus fewer amphours will change nothing concerning Peukert's Law. Running more batteries of equal amphours would, however.
For charging, what amperage would you recommend (per battery)? And I shouldn't run into any problems charging in parallel as long as I manually check voltages once in a while, correct?
Specific to the battery. The B&B SLAs I'm looking at charge at 6A.
As you may have noticed, I am stuck on SLA because of its cost advantage per Ah and also because of its (perceived) relative ease of charging. I do not feel that the extra weight will bother me, but I welcome any feedback on the subject. Just know that at this point I am definately not ready to start opening up powertool battery packs or wire my own protection circutry.
What measures will I need to take to protect my batteries, and what factors affect battery performance temporarily and permanently, assuming all SLA cells?
Both rate of discharge vary inversely with usable capacity (Peukert's). Battery capacity varies with temperature on a per-charge basis, and that deep discharges negatively affect battery capacity over a battery's lifetime. SLA's need to be stored charged at room temperature or mildly higher, and a floating charge can be wise. With a quality controller, it is safe to leave batteries plugged into the charger nearly indefinitely.
How exactly does the throttle on these kits work?
The throttle itself controls a voltage between 0V and 5V at a low current, which in turn cues the controller to vary the voltage supplied to the motor accordingly. The controller generally limits the current supplied to the motor, though aftermarket tools like Cycle Analyst can make the limit even lower.
I plan on using an immediate-start controller. What is the Hall effect, and what is a Hall effect sensor in this context? Do I need to buy and install a Hall effect sensor in addition to the controller, or will the clyte controller have that function built in?
The Hall effect is used to determine the rotational velocity of the stator relative to the permanent magnets (I think). The motor has a sensor already mounted and has wires for the sensor exiting the hub for the controller. It requires no additional mounting. By sensing the wheel's RPM, it allows the controller to sequence current so that it can provide power at very low speeds. The Hall effect sensor can be used as to provide information to a computer like the Cycle Analyst, which can calculate fun things like RPM, velocity, distance and such from the data.
How should I fix my braking problem? My bike currently has trouble stopping, and at twice speed with 1.5 times the mass, if I don't do something about it, prayer will be more effective. Considering that the Divine in my experience works imperceptibly and with a sadistic sense of humor, that option seems unviable. Can I buy a kit for rear and front disc brakes that will fit with the motor and not require welding to install? If so, can I do it online or will I need to check my LBS?
My LBS can take care of it. It'll take some welding to repair the front brakes, and they can add beefy rear brakes. Discs are out of the question, as my frame is not designed for them.
With the controllers from ebikes.ca, how is braking handled? I've seen clyte gear with cruise controllers and ebrakes in addition to the throttle, and ebikes.ca doesn't seem to have either. I assume I'll need a way to quickly cut out the motor in traffic, and if possible I'd like to use the motor to regeneratively brake. Will the controller I'm looking at do this, and will I need to do any additional wiring to achieve it?
Getting power off of regenerative braking won't happen, period. Also, kits generally will not use the motor to brake. It can be wired by hand, but it isn't really worth it.
Since the motor is always mechanically engaged, how can I minimize its effects if I want to run the bike on pure muscle power? What can I disconnect make the motor as imperceptible in this state? Or, would it be more transparent to run the motor at a very low power setting to just overcome its own resistance and if so, is there a convenient way to set this?
It's a big, heavy motor. That said, it won't be too bad, as long as the batteries' weight is removed. Peddling it in this manner will not damage the motor.
Will I be able to peddle current into batteries if I both want exercise and have low batteries? Is it possible with the controller I'm looking at, and would trying to do such have any meaningful impact?
No. The reason is that to charge the batteries, the wheel would need to spin so fast that the motor generated >72V, which is nigh impossible on muscle motors.
What tires will I want to use? Obviously I want to use something a lot flatter, but I want it to be durable. I plan on staying on pavement, but I don't want to pop an innertube by riding off a curb. On that note, will I need special innertubes, and will I see any benefit from higher tire pressure?
Higher pressure will be needed to an extent because of the extra weight, but lower pressure to an extent will provide better handling. 60+ PSI is recommended. I actually bought a pair of Town+Country (made by Continental) from my LBS, which are very slick on the center, groovy on the outsides, and very, very puncture resistant.
Will I need a torque arm? My gut says yes, considering that it's a basic bike with no really fancy reinforcement. If I do need one, what should I look for, where should I get it, will I need one for each side of the wheel, and how can I make sure it will fit on the bike?
I shouldn't, as long as I make as sure as humanly possible that the motor is bolted into the dropouts as tightly and flushly as humanly possible. Should I need to modify the dropouts to handle more torque, it'll need to be a custom job, as most likely any aftermarket arms will not be suitable.
What sort of helmet will I need? Is there any point to wearing a bike helmet at 30mph, or should I invest in a motorcycle or motocross helmet?
Generally all bike helmets sold are rated to the exact same safety standard. That said, a full helmet, such as one worn by downhill racers or motocross riders is a very good investment.
Should send any of these questions to the folks ebikes.ca? I've read that they're also helpful, and not only would they better know their own kit but also they would have a more vested interest in answering the questions of a potential customer.
Definitely! I called their store, got Justin, and just went down this list. He was very helpful, and if an answer didn't come from these forums, it was from him. When I order my parts, he's getting my business.
I know that that is a lot of questions, but it's better to get them answered sooner than later. And I've learned that in electronics, attention to detail is very important. Thanks in advance for any and all help you folks can provide.
Addendum: I keep thinking of other things to ask, so I'll keep adding them in as readable of a format as I can.
What is forced air cooling for a controller in this context? Do controllers have heat problems, and if so under what circumstances? Do the FETs have heatsinks on them in general, and if not can they be added?
Well, I preparing to order my parts within the next two weeks, and I'd like to run everything past the folks in these forums. If you spot any potential problems in my understanding or any room for improvement, by all means speak your collective mind. I've got a lot of questions, so please answer any you can. It'd be a great help to know all I can before placing an order.
The basics: I am starting completely from scratch. The only piece of kit I currently own is a basic steel-frame unsuspended mountain bike, with 15 gears, awful brakes, and 26" wheels with offroad tires.
I plan on running a 5304 motor in a 26" rear wheel at 72v off of 6x12v 18Ah SLA batteries through a 72v 40A controller. I'll be ordering everything I can from ebikes.ca (especially the controller, as I like what I've seen of their customized clyte controllers with plugs for their Cycle Analyst), and what I can't get from there I will be buying off of PowerRideStore (primarily the batteries and electrical connectors).
I'll be connecting everything with Anderson Powerpole connectors so that I can easily remove anything I need, especially the batteries. For charging, I plan on disconnecting all the batteries, reconnecting them in parallel, and using a good 4-stage car battery charger.
I am in the hub motor camp because of its simplicity. I can solder but not weld, so chain systems are out of the question. I'm a university freshman, so this will be my primary form of transportation around campus and around town, but just as importantly it needs to be fun to ride. Do note that I am both young and stupid, which will affect my views on rider comfort and speed, respectively.
For legalities, I plan on keeping a printout of the relevant Federal law (pedals, 750w, 20mph) and using the Cycle Analyst to limit my speed to 20mph and amps to 10 if I ever am somewhere where I feel likely to come under scrutiny... but I plan on finding the bike's limits, on... er... ah... private property... right.
Now, for my questions. If I found an answer, or someone posts one, I'll put it in bold directly following the question.
What gauge wire will I need to wire everything so that I'll have enough headroom for any future changes? I don't want to ever have any issues with my cables not being able to carry peak current.
10 AWG should be fine
I have never soldered things to carry anywhere near this current. Are there any special instructions I need to follow, or perhaps a guide somewhere? I want to do all of this myself, but I also want to do it right.
Make a clean, secure connection. Do not use so much solder that connections will have difficulty fitting into the Anderson casings
As far as I know, Anderson Powerpoles are the best way of making disconnectable high-current DC terminations. Are there better options, or is that the way to go?
They will be more than adequate, and ebikes.ca kit even comes with Anderson connectors on its controllers and motors
I can only seem to find Powerpoles rated for 30A. Can I safely use them? As with the cables, I don't want to have any issues when I push things.
The amperage rating on Powerpoles refers not to what the connection is rated to handle but rather what gauge wire the crimps are designed to accept. The 30A connectors will accept 10 gauge wire.
Would I cause damage by running an even higher voltage? The ebikes.ca site says that their 72V controller will be fine up to 100v, but I'd rather not have to deal with blown MOSFETs.
I talked to Justin at ebikes.ca, and although the capacitors and MOSFETS are rated to 100V, a 96V nominal voltage battery comes off the charger at well over 100V. However, as of 10/23/07, they are expecting a shipment from China in a few days which will include new 72V 50A controllers with MOSFETS with significantly lower resistance (I cannot remember how many miliOhms), which should be easily able to withstand a higher voltage setup.
If not, perhaps would I be better off running, say, 8 batteries with fewer Ah each for 96V and a similar number of watt-hours? Aside from the greater torque and top speed, would using smaller batteries at a higher voltage lead to a lower amp drain and thus be better with respect to Peukert's Law? And would it be more fun?
Running more volts on more batteries with fewer amps and thus fewer amphours will change nothing concerning Peukert's Law. Running more batteries of equal amphours would, however.
For charging, what amperage would you recommend (per battery)? And I shouldn't run into any problems charging in parallel as long as I manually check voltages once in a while, correct?
Specific to the battery. The B&B SLAs I'm looking at charge at 6A.
As you may have noticed, I am stuck on SLA because of its cost advantage per Ah and also because of its (perceived) relative ease of charging. I do not feel that the extra weight will bother me, but I welcome any feedback on the subject. Just know that at this point I am definately not ready to start opening up powertool battery packs or wire my own protection circutry.
What measures will I need to take to protect my batteries, and what factors affect battery performance temporarily and permanently, assuming all SLA cells?
Both rate of discharge vary inversely with usable capacity (Peukert's). Battery capacity varies with temperature on a per-charge basis, and that deep discharges negatively affect battery capacity over a battery's lifetime. SLA's need to be stored charged at room temperature or mildly higher, and a floating charge can be wise. With a quality controller, it is safe to leave batteries plugged into the charger nearly indefinitely.
How exactly does the throttle on these kits work?
The throttle itself controls a voltage between 0V and 5V at a low current, which in turn cues the controller to vary the voltage supplied to the motor accordingly. The controller generally limits the current supplied to the motor, though aftermarket tools like Cycle Analyst can make the limit even lower.
I plan on using an immediate-start controller. What is the Hall effect, and what is a Hall effect sensor in this context? Do I need to buy and install a Hall effect sensor in addition to the controller, or will the clyte controller have that function built in?
The Hall effect is used to determine the rotational velocity of the stator relative to the permanent magnets (I think). The motor has a sensor already mounted and has wires for the sensor exiting the hub for the controller. It requires no additional mounting. By sensing the wheel's RPM, it allows the controller to sequence current so that it can provide power at very low speeds. The Hall effect sensor can be used as to provide information to a computer like the Cycle Analyst, which can calculate fun things like RPM, velocity, distance and such from the data.
How should I fix my braking problem? My bike currently has trouble stopping, and at twice speed with 1.5 times the mass, if I don't do something about it, prayer will be more effective. Considering that the Divine in my experience works imperceptibly and with a sadistic sense of humor, that option seems unviable. Can I buy a kit for rear and front disc brakes that will fit with the motor and not require welding to install? If so, can I do it online or will I need to check my LBS?
My LBS can take care of it. It'll take some welding to repair the front brakes, and they can add beefy rear brakes. Discs are out of the question, as my frame is not designed for them.
With the controllers from ebikes.ca, how is braking handled? I've seen clyte gear with cruise controllers and ebrakes in addition to the throttle, and ebikes.ca doesn't seem to have either. I assume I'll need a way to quickly cut out the motor in traffic, and if possible I'd like to use the motor to regeneratively brake. Will the controller I'm looking at do this, and will I need to do any additional wiring to achieve it?
Getting power off of regenerative braking won't happen, period. Also, kits generally will not use the motor to brake. It can be wired by hand, but it isn't really worth it.
Since the motor is always mechanically engaged, how can I minimize its effects if I want to run the bike on pure muscle power? What can I disconnect make the motor as imperceptible in this state? Or, would it be more transparent to run the motor at a very low power setting to just overcome its own resistance and if so, is there a convenient way to set this?
It's a big, heavy motor. That said, it won't be too bad, as long as the batteries' weight is removed. Peddling it in this manner will not damage the motor.
Will I be able to peddle current into batteries if I both want exercise and have low batteries? Is it possible with the controller I'm looking at, and would trying to do such have any meaningful impact?
No. The reason is that to charge the batteries, the wheel would need to spin so fast that the motor generated >72V, which is nigh impossible on muscle motors.
What tires will I want to use? Obviously I want to use something a lot flatter, but I want it to be durable. I plan on staying on pavement, but I don't want to pop an innertube by riding off a curb. On that note, will I need special innertubes, and will I see any benefit from higher tire pressure?
Higher pressure will be needed to an extent because of the extra weight, but lower pressure to an extent will provide better handling. 60+ PSI is recommended. I actually bought a pair of Town+Country (made by Continental) from my LBS, which are very slick on the center, groovy on the outsides, and very, very puncture resistant.
Will I need a torque arm? My gut says yes, considering that it's a basic bike with no really fancy reinforcement. If I do need one, what should I look for, where should I get it, will I need one for each side of the wheel, and how can I make sure it will fit on the bike?
I shouldn't, as long as I make as sure as humanly possible that the motor is bolted into the dropouts as tightly and flushly as humanly possible. Should I need to modify the dropouts to handle more torque, it'll need to be a custom job, as most likely any aftermarket arms will not be suitable.
What sort of helmet will I need? Is there any point to wearing a bike helmet at 30mph, or should I invest in a motorcycle or motocross helmet?
Generally all bike helmets sold are rated to the exact same safety standard. That said, a full helmet, such as one worn by downhill racers or motocross riders is a very good investment.
Should send any of these questions to the folks ebikes.ca? I've read that they're also helpful, and not only would they better know their own kit but also they would have a more vested interest in answering the questions of a potential customer.
Definitely! I called their store, got Justin, and just went down this list. He was very helpful, and if an answer didn't come from these forums, it was from him. When I order my parts, he's getting my business.
I know that that is a lot of questions, but it's better to get them answered sooner than later. And I've learned that in electronics, attention to detail is very important. Thanks in advance for any and all help you folks can provide.
Addendum: I keep thinking of other things to ask, so I'll keep adding them in as readable of a format as I can.
What is forced air cooling for a controller in this context? Do controllers have heat problems, and if so under what circumstances? Do the FETs have heatsinks on them in general, and if not can they be added?
This is where Lithium rules !!! 
