Building a new Electric Bike; for hills!

[davidg11]

Hi all,

New here. But I've been reading a lot, so I hope I don't sound completely clueless. Just partly!

I live in the USA. I weigh 185 lbs. I'll just converting a simple older Mongoose steel framed mtn bike. 26" tires. Range-wise I can't ever see biking more than 13 miles in one round trip excursion (downhill for half of the 13 miles or 6.5 miles). Most of my trips would be around 6 miles round trip (downhill for half of that or 3 miles). And I have a long 1.5 mile 4-5% grade incline in those round trips
that I'd like to get 25 mph uphill on the 4-5% grade 1-2 mile incline and then jumps up to about 8+% grade in the final 1/5 mile.

I won't be making a Frankenstein battery, so I think I will be buying a 48V 10ah ($348) or 48V 15ah ($485) LiFePO4 battery from most likely ping battery unless I hear of another reliable but cheaper battery LiFePO4 pack. Feel free to mention any other battery competitors! (or is there a link?)

I also have decided on a front hub DD motor.

Now the problem is, even after reading a lot, I have no clue what motor or control system I should use. I looked at ampedbikes.com and from what I gather, they make their motor packages for a 36V battery and not a 48 volt battery. Amped has a "500-750W" motor with 9 x 7 windings (zero clue what 9 x 7 means( or what 9C means) or any of these other motor terms I keep reading) and comes with all of the following for $346:

Microprocessor controlled brushless speed controller 22A 35A max (but I have no clue what these controller numbers mean)
Spare Grips.
Brakes with motor cutoff switch.
Thumb Throttle with Battery indicator lights.

I'm trying to also keep this entire system under $800US...but the larger battery does push this ampedbike system, if it is indeedr what I need, up to $830

Now I can do almost the same setup from Cohnismotor.com and the total is $766 but with them it is a 1000 watt motor and THEIR 48V 15ah LiFePO4 battery.

And Cohnismotor's controller is:
Voltage: 48V
Power: 1000W
Size: 21.4*9.5*4.5cm
Net Weight: 0.68kg
Max. Cut-off Current: 30A
Max. Cut-off Voltage: 55V
--------------------------------------


I guess I'm mostly trying to narrow down what overall system I need for my location and trying to understand the difference in motors and controllers for my situation. But price does matter.

I guess after that point, I can concentrate on suppliers.

Any help appreciated! Thanks! Great forum!

 

[LI-ghtcycle]

Welcome!

The first thing you should know, is almost no one uses a 36V kit at 36V. 48V will work fine for that amped bikes kit, or one from ebikes.ca, Ebikekit.com, etc. when you are talking a DD motor.

Geared motors can be optimized for one specific voltage, and if you go over that voltage, they will not give you any more speed, depending on the gearing.

I think you are on the right track going with a DD to start with. 9 x 7 refers to the windings, I don't really understand the specifics myself, but generally, the 9 x 7 is a good choice as it is a good all-around motor, and will give you a flat road speed of 27 MPH and climb an 8% grade at 12 MPH no pedaling, I weigh with-in a few pounds of you, so with an average bike, this should be the same performance for you with that ping 48V.

Getting 25 MPH up hill is entirely possible, but for the last bit that is so steep, to get that same speed will be very expensive, and you better double that estimate if you really need to go that fast up-hill.

I am hoping to accomplish nearly the same goal (I want 20 MPH up a 10% grade) but this will take in the neighborhood of 2000 Watts no matter what method you use.

Don't be fooled by one company selling a 1000 Watt motor and think it is so much more powerful than the other company's 500W. The wattage is really going to depend on the voltage x the amps used, so that "500W" motor at 36V will be pretty much the same as the other company's 1000W at 48V, if you are running the same voltage and amperage.

48V * 30A = 1440W, if the motor can sustain this power level (most any DD hub motor will with the exception of the really small low voltage ones like the 24V cute motors.

The 9 x7 (weather 9C or Other company) is a really good motor for hills since it sheds heat well, and is cost effective. If you really want light however, then you need a mid-drive or RC motor drive with a considerable reduction, i.e. friction drive, or chain reduction drive, etc. Those are not as "plug and play" as a hub motor however, so unless you're pretty handy with metal fabrication, and have some money to burn experimenting, stick with the hub motor at least to start out.

Good luck!

 

[davidg11]

Ok. About 2-3 years back I bought a 36V "250 watt" front wheel DD motor made by Suzhou Bafung Motor Science Co. Ltd. for my front 26" wheel (off Ebay of course). It was paired with a 36V 7amp hour SLA battery. The controller label says 36V, max amp rating 15A, and rated current is 7A, low voltage (and a word I cant read since the label ripped) 31.5V Throttle control 1.5V -4V

I realized immediately the power for hills was pitiful. Though I guess on the flat it was fine enough.

Are you saying watt ratings for motors mean almost nothing, and I could simply replace my old SLA battery with a 48V 15ah lifepo4 battery and replace my old controller with some sort of new controller (no clue what I would need in this modification) and I might not even require a new front wheel motor/system?

I'd certainly save a few $$$ if all I'm doing is replacing an old controller and an old battery.

Thanks

 

[oldpiper]

Ok. About 2-3 years back I bought a 36V "250 watt" front wheel DD motor made by Suzhou Bafung Motor Science Co. Ltd. for my front 26" wheel (off Ebay of course). It was paired with a 36V 7amp hour SLA battery. The controller label says 36V, max amp rating 15A, and rated current is 7A, low voltage (and a word I cant read since the label ripped) 31.5V Throttle control 1.5V -4V

I realized immediately the power for hills was pitiful. Though I guess on the flat it was fine enough.

Are you saying watt ratings for motors mean almost nothing, and I could simply replace my old SLA battery with a 48V 15ah lifepo4 battery and replace my old controller with some sort of new controller (no clue what I would need in this modification) and I might not even require a new front wheel motor/system?

I'd certainly save a few $$$ if all I'm doing is replacing an old controller and an old battery.

Thanks

Well, you should be able to save a few $$$ here, all you really need to do is replace the controller and battery. LI-ghtcycle has good advice. I have an AmpedBikes motor (as does he, IIRC), and they are good hubmotors. If I went with a whole new kit, I'd definitely go with that over the ConHis kit, but your Bafang should be able to do OK. The watt rating doesn't "mean almost nothing," but it is a very conservative rating and you should be able to at least double it without any problems. The controller, on the other hand, does limit the current (pulling/pushing power) and you need something better. Fortunately, they're relatively cheap, and I'd look in the "Items for sale - New" threads here for one of Edward Lyen's controllers. He has a sterling reputation among members here (and members here know what they're talking about, as you've found out by reading the boards). How big? I guess 12 FET, but someone else may suggest something bigger.

Unfortunately, you have exactly the wrong battery to do what you want. SLAs cannot put out much current at all (about 1/20 C, which means that they would discharge completely in 20 hours; for a 7 Ah (amp-hour) battery this means that it can put out 7/20 amps max), and the current is what drives the motor. Since the battery can't put out the current, is you were to put a voltmeter across the battery while you go up that hill (easy enough by connecting it to your charging connector - make an adapter, don't try it with the probes that come with the meter, too easy to short out with dramatic effect ) you would see the voltage take a real dive as you slow down. Plus, your batteries being 2-3 years old, they likely have significantly less than 7 Ah in them now. 7Ah in itself with a good battery is probably pushing it for as far as you want to go on a charge, particularly for an SLA, which only yields about 1/2 its rated Ah at the currents an ebike draws.

To get good climbing, you need something better than an SLA: LiFePO4 or LiPO are the ones mostly commonly recommended here (I have neither at the moment, so I have to quote others). They both have much better current output ("C"s) than SLA (as does just about anything). LiPO can put out much higher instantaneous current, but LiFePO4 is generally thought of as being less of a pain to keep balanced (all cells at the same voltage after a charge) and they have higher charge/discharge cycle ratings (will last longer). The Ping batteries are generally thought of here as the most reliable LiFePO4 ones, I can't remember who has the best rep as to LiPO, although the AmpedBikes lithium battery seems to have gotten some quite good comments. Also, 36V probably won't get you up the hills quite as fast as you want to go (I'm not sure about the LiPO, any others want to fill in here?), you might have to go with 48V, but you could get 36V, see how it goes, then add another 12V (or 24V, 36V, 72V and upgrade everything else again if you aren't satisfied. Just putting 2 packs in series isn't much of a "Frankenstein battery").

As you can see, I can be a bit longwinded, but hope this helps. As always, YMMV.

Cameron

 

[dogman dan]

Wow more longwinded than me.

Yes, if you don't have a really cheap brushed hub motor, you can replace the controller with a "36v" infineon controller such as found in the 9 continent kits, put a 48v battery on it, and have 1000-1200 watts peak power.

The rub is figuring out the phase and hall sensor wiring sequence. It's known for the more common motors, but oddballs, you'd have to sort it out yourself. Not really that hard, but for some, confusing to the point of being impossible.

To Davidg11, you won't be going 25 mph up steep hills. You can if you overvolt, but 6 miles of steep hill overvolted could easily fry a motor. Stick to 48v, and pick a gear where you can pedal briskly, but not to the point of blowing Yourself out. You should be able to climb 15 mph reliably, and get that 6 miles done with minimal effort.

The best hubmotor for climbing really long steep hills is the slower winding 9 continent. 6x10, or 2810 depending on the vendor. This motor is slooow, but really does heat up less climbing 10% than a 2807. The price you pay is top speed, with only about 20 mph on 48v on the flat.

For sale right now for awhile, in Methods ad in the for sale new section of ES. He also has the 8x8/ 2808 motor, that climbs well and is not quite so slow.

Buying the kit alacarte, would likely blow your budget though. Nothing really wrong with the conhis motor plan for the budget concious rider.

 

[LegendLength]

Just ensure you get a controller that supports Cycle Analyst if you wish to use one. I learned that the hard way.

 

[spinningmagnets]

low voltage (and a word I cant read since the label ripped) 31.5V

For a 36V battery pack, the "low voltage cutoff" (LVC) is around that voltage. An LVC prevents you from draining the battery down so low that the battery is damaged.

Some controllers have a sudden LVC, some ramp down the power as you near the LVC as a warning, and others have an adjustable LVC.

Laws vary from state to state, and also very much by country, but the federal law in the US for having a powered bike that doesn't require a license or registration (as an electric moped) is that it must be limited to 20-MPH, and 750W of power (roughly one horse-power).

Its a bit of a "wink and a nudge" to make a bike kit that works very well at 48V (the most popular voltage, which results in about 1,000W of power) but it only puts out 750W and 20-MPH at 36V. But, doing that prevents them from having to do the tapdance that includes a label that says "for off-road use only", and other silly things...

 

[davidg11]

Great guys. Well it looks to me I have really nothing to lose if I keep my OLD "36V 250W" front hub DD motor for now and simply buy and replace a new LIFEP04 battery with a new controller to run it.

Because it sounds like the worst case scenario is if for some reason I don't like my old "36V 250W" front hub DD motor, I can simply replace it and keep the new 48V LIFEpo4 battery and leave the decent controller as is.

I'm not sure if I was making this clear earlier. I will be buying a 48V lifep04 battery to replace that old SLA battery regardless of whatever motor/controller I decide on. I only threw in that info to show that system was terrible on hills.

So the only question I have now is what controller is compatible with my 36V 250W motor which will deliver the power I need to fly up hills without killing the life of the battery prematurely.

So a couple of questions on your controller answers:

"you can replace the controller with a "36v" infineon controller such as found in the 9 continent kits, put a 48v battery on it"

So you are saying I need a 36V controller regardless of the fact that I will be using a 48V battery? Would a 48V controller work? (I've read posts where a guy throws on a infineon 48V 40 amp controller and flies up hills) Are you saying I need a 36V controller because the motor is rated 36V? Or can I, or should I, use a 48V controller?

"one of Edward Lyen's controllers. He has a sterling reputation among members here (and members here know what they're talking about, as you've found out by reading the boards). How big? I guess 12 FET, but someone else may suggest something bigger."

What does 12 FET mean?

I don't mind pushing a new Ping LIFEP04 battery a little. Again, I'm considering buying a 48V 15AH ping lifep04 battery. But just from reading, I don't want to wear out the battery life too prematurely either.

Thanks for your input guys!

 

[oldpiper]

"one of Edward Lyen's controllers. He has a sterling reputation among members here (and members here know what they're talking about, as you've found out by reading the boards). How big? I guess 12 FET, but someone else may suggest something bigger."

What does 12 FET mean?

FET - field effect transistor. Basically, how the majority of the speed controllers are made is that the FETs are there to push power to the motor, each one can take only so much power before it dies. So, more FETs, higher power can be pushed through the system (an exception is Jeremy's "Simple BLDC Controller," which uses a few very high power FETs instead of many regular ones, but he's still developing it, there's an active thread about it) and you can take those hills, but 12 should be plenty for your requirements, with room for future growth, I think (someone correct me if I'm wrong).

Cameron

 

[RallySTX]

Hi David, and welcome to ES. I feel funny now, offering advice, you actually have more experience than me. I have never turned a wheel in anger on an Ebike before. I am still building my first bike. However I have been reading, and asking questions on several sites. Dont worry about the FET number. There are several good 9 FET controllers that will suit your application. They will work with 36, and 48 volts. They offer 20 to 25 amps of power. And they are cheap. I got mine delivered to my home from a local Ebiker for $40. The things to look for in the controller anr it's operating voltage range, it's stated amp capacity, and the types of connectors it has. Many 36 volt controllers came built to handle 48 volts. Mine is this way, but because it isn't programmable it is stuck with a low cutoff voltage. I know you are looking to keep this project under $800, but that will be tough. Consider getting the stuff it takes to do this well, over the amount of cash you spent. I say this because there are extra things that will help you succeed in the long run, that would otherwise not be justifiable. A cycle Analyst from Grin Cyclery is a must have, along with a controller that has a CA connector. My controller has no CA hookup, so I will have to rig up a volt meter to keep an eye on things. Also, I would be very cautious about using a front hub motor on Composite forks, especially with 48 volts. You will need to use tourqe arms to support the axle. I would advise against it at all. Even in the rear, especially with aluminum, you need tourqe arms. I would avoid the Ping batteries, for several reasons. They are large and hard to mount on a bike. They are soft, requiring protection from outside exposure and impacts. They are from China, so returns are a pain, and some are bad. The batteries at Ebikekit with aluminum cases are well made, easy to mount, light, and built strong enough to stack them on a rear rack for extra range or speed. For a no problem, plug and play setup, they win the cheese.
Brian L.

 

[MadRhino]

More fets, means you can feed more power or keep the controller colder when limiting power, which is good for climbing. Then, you have to consider the limits of your battery, because feeding your motor with too high power can quickly kill a 15Ah Ping.

Climbing fast requires either, high power with a fast wind motor, or high voltage with a slow wind motor. The second option is easier, for it produces less heat. Both options require a biger battery, more series for high voltage, more parrallel for higher power.

Lipo's are good for climbing, because they can make a bigger battery with less weight, and they can deliver high power without damage.

The ultimate climbing bike, can't be built with a hub, cause you'll always have to find a compromise between those factors: Heat, speed, torque, efficiency, reliability. Still you can do very well with a hub, when you are good at ballancing compromises and you have a well definite target performance. The best climbing can be achieved with mid drive, because you can gear the ratio to optimize your target performance and change it at will. It keeps your build lighter too, but then, you have to live with noize.

 

[neptronix]

For hills, you want amps, amps, and more amps.
If you are taking steep hills for an extended period of time, you also probably want a DD motor. A DD motor can handle tons of power without breaking unlike a geared where the plastic/nylon gears are the weakest link.

Get something with a programmable infineon controller, preferably a 12 fet. Those controllers can confidently output 35amps.. i believe some people are even running them at 45amps or more.

Stock DD controllers in kits usually put out 17-25amps.. which is decent power until you hit a hill. So no cheap pre-built kit is going to give you the power you want.

For voltage, yeah.. 36v is quite weak. 48v and beyond is what you want for DD motors.

BTW, cell_man is selling his DD kits with infineon controllers for an extra ~$30-$70 or so. You're obviously looking to save money if you're looking at the conhismotor. Well, you might wanna check his out too. They are cheap and you can get a good controller with them. I think this combo will suit your needs.

 

[davidg11]

Hey thanks for all the help and input guys. This site is amazing.

Ok, here is my plan thus far.

I already own a Suzhou Bafang front hub, non-geared DD motor. It is labeled 250W 36V. The only number on the entire thing is BF801D12325. I went to the Suzhou Bafang Chinese website and google searched that "part number?" and have no clue as to its windings, etc...and I'm not dissecting the motor to find out either. But the diameter of the actual motor is just shy of 5 inches or 120mm.
I sent an email to them so I can get a better handle on what I have.

My plan is to pair it with a ping 48V 15AH lifepo4 battery.

Ping states the following specs for this battery:

Rated Discharging Amperage: 15 Amps
Max Continuous Discharging Amperage: 30 Amps
Maximum Discharging Current: 60 Amps
Discharging Cut-off Protection: 40-50 Amps

I do not plan on buying/hooking up a cycle analyst. I do not plan/buying anything for power braking. I do not plan to spend $110-$155 on an Inferion controller because it seems far more controller than I need to drive a motor and throttle control, and it is a far higher price that I'd like to pay. For an electronics/performance/builder enthusiast, I can definitely see its appeal. It seems incredibly robust.

The Lyen 9FET or 12 FET controller sounds interesting because his 9FET is $89, but I can not, for the life of me, find this guys store/web site or link to see what a 12 FET goes for or its specs or its price. If there is a link to him somewhere, please link me!

And the cheapest option...and again, I still haven't a clue if I need a 36V controller or 48V controller (or if it even matters) for the motor and battery I previously mentioned, because if I understand this right, it is all about the amperage drawn (torque) from this ping 48V battery to get up hills.

So given the battery which I will be buying, and the obscure motor I own.... It sounds like I need a controller that can provide 30-40 amps. And with the stats above, it sounds like drawing 35amps would be ideal to draw from a controller.

So that all said, the CHEAPEST controllers that I have found and are sold on Ebay from "e-crazyman" are the following:

A 36V/800W controller with the following claimed stats:

Rated Voltage: 36 Volts
Rated Power: 800 watts
Under Voltage Protection: 31 Volts
Maximum Current: 40 Amps

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=260440247079&si=XD0cOfjYuI8HqjA6wI98V%252F2EL5k%253D&viewitem=

And this costs: $45
---------------------------
OR

they also have a

48V/600W controller with the following claimed stats:

Rated Voltage: 48 Volts
Rated power: 600~800 watts
Under Voltage Protection: 41 Volts
Maximum Current: 30 Amps

And this costs: $68

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300352534034
--------------------------------------------------------------

Now to be honest, I'd love to throw 40amps output from this battery into this motor especially for only $45. But what I do not understand, being a electrical dummy, is whether or not I need a 36V controller or a 48V controller. Do I match the voltage of the controller to my battery choice? or do I match it to what it is labeled on my motor? Or does it simply not matter on a controller if it says 36V or 48V?

I really want to max out that motor, and I do not care if it melts in doing so..just not right away hopefully..lol I have no problem replacing it if need be, because otherwise it will sit as a brick in my garage. If it melts, and I have to buy a better, newer motor so be it. That had been my original intent in the first place.

My only concern is not killing the $485 battery, and I'd be happy with 500+ charges off of it even though the claim is 1000+ charges.

I'd be quite happy to upgrade my old system for a $485 battery and a < $100 controller.

If there is a disadvantage or drawbacks to those two cheap Ebay controllers above, I'd like to hear opinions on it ( he has 2000+ sales on Ebay...a LOT of controllers sold and 100% feedback (zero complaints).

I do like this idea that I can tinker around with the amperage level on a Lyen controller. But the question is whether or not I'd actually do that or not. I'm not a huge "tinkerer". I prefer plug and play and lets hit the road!

Of course I am unable to find a 35 amp controller which is what I think would be perfect, so it is in between the continuous discharging amperage of the battery, but below the cutoff protection of 40-50amps.

I just wanted to add....power/performance on hills is the most important thing here. My range is going to average 6.5 miles for each charge and only 2 miles of that is going to be an upward incline.

Any thoughts/comments/opinions appreciated!

 

[John in CR]

Don't underestimate that hill. 25mph up an 8% grade is going to require 1500-1600W at the wheel, so 2000W or more out of the battery. A 5% grade is going to require 1200-1300W at the wheel, and that's with no headwind. Just a 10mph headwind pushes the power required at the wheel 500-600W higher at 25mph. In addition, to maintain 25mph up an 8% grade, your bike needs to be capable of more than 40mph on the flats.

Getting up a hill 100-200 yards is a completely different animal than one miles in length. Miles means you're looking at continuous duty, and at 50 volts you'll need a proper controller that can handle 40-50 amps, and a battery that can handle it.

My suggestion is to lower that uphill speed target. Also, select a motor wound for torque, not speed. If something more like 15-18mph up that hill is acceptable and 25-30mph max speed on the flats, then yes you can probably pull it off in the price range you're looking at.

John

 

[neptronix]

I already own a Suzhou Bafang front hub, non-geared DD motor. It is labeled 250W 36V. The only number on the entire thing is BF801D12325.

Are you sure it's not geared? I've never heard of a non-geared bafang hub motor. That sounds like a Bafang 8fun, especially at 250watt rated.

In that case, that line of motors is known to be good for 500 watt / 1000 peak, and not a hell of a lot more power than that. That certainly won't do the job for that hill.

My plan is to pair it with a ping 48V 15AH lifepo4 battery.

Rated Discharging Amperage: 15 Amps
Max Continuous Discharging Amperage: 30 Amps

For what you're going to be doing, you're gonna want to pull 30 amps or more for a long period of time. That battery will not cut the mustard, even if you got the 20ah battery, it may barely eek out enough power, but you will abuse the heck out of it in the process and it will voltage sag like crazy. You need lipo or a pack made out of high quality 2c-5c cells, unlike the weak little things in the ping pack that only output ~1c with short bursts of ~2c.

The Lyen 9FET or 12 FET controller sounds interesting because his 9FET is $89, but I can not, for the life of me, find this guys store/web site or link to see what a 12 FET goes for or its specs or its price. If there is a link to him somewhere, please link me!

Those are infineon controllers, and i would reccomend getting the 12fet because you will have wiggle room to do 40amps and probably even above that. He sells things on ES and i don't believe he has a web store, check out the 'for sale - new' section on this board.

ecrazyman are okay controllers, but they have no programmability so you will be in the dark about some things. The upside to the infineons is that you can adjust the amperage they can spit out, rather than be stuck in one amperage and if it isn't working for you, get another controller ... and yes, very very robust.


So here's an idea for you. Since you are looking to save some money, Cell_man has started selling his DD kits with an option to add a 9fet or 12fet infineon controller. The total price if you do sea shipping for the motor + controller should be about $300. That is a setup that will easily pull 2000w-3000w.

I am not sure that level of power will do 25mph up a hill though. But it comes close. The other option is a crystalyte ( spendy ) or 9c ( kinda spendy ), both motors which many users on here have taken all the way up to 5000watt and beyond.

As for batteries, lipo is the cheap way to go but it can be a pain in the butt. Making a pack out of headways would be awesome if you have the room for it on your bike.

I don't know of anyone who makes a 'plug it in and forget it' lithium battery that can sustain high amp draw though... for a reasonable price anyway. At this level of power it is pretty much 'roll your own'.

 

[neptronix]

My suggestion is to lower that uphill speed target. Also, select a motor wound for torque, not speed. If something more like 15-18mph up that hill is acceptable and 25-30mph max speed on the flats, then yes you can probably pull it off in the price range you're looking at.

John

Yeah, what he said.
Looking to head up a hill at 25mph and not spend a lot of $ are contradictory goals :lol:

 

[davidg11]

If geared means on the back of the bike with the motor gears hooked to my chain. No. This Bafang motor is my front rim/tire hooked onto the front forks and nothing else.

Ok, I probably should go over my route and my expectations (and give specifics) since I just did the distance via car and verified via "map my ride". The normal range for me is less than I thought and I'll give a realistic walk through of the grade I'm dealing with.

I start the route going downhill to eventually 0 grade from my house to my destination which is 2.3 miles away. No real use of the motor needed except maybe intermittently for a fun power boost along the way. There would be no charging of the battery at my destination. And the bike/battery would be resting for a couple of hours while at my destination. Then on my return it is 2.3 miles back on the same route.

And my 2.3 mile return trip looks like this

For the first mile it goes from 0% to 2% grade. Then the second .8 mile after that it goes from 2% to 5% grade. And then on the final .5 mile it goes a lot steeper from 5% to 8.5%.

On the first returning mile I want to go 25-30 mph. On the final 1.3 miles I can accept as low as 15mph.

Now knowing all of this, will ping's 48V, 15AH battery specs allow me to do this if get some sort of variable amp controller (like a 12FET) allowing me 30+amp - 40 amp variability?(I think you sold me on Ryen's).

I'm not sure what the 1C-2C means...I mean I understand these ping batteries don't discharge at as high of rate as lipos, but if the "max continuous discharge" rate of pings are at least 30Amps and the BMS amps cutoff is 40-50amps, shouldn't a 30-40amp variable controller do the trick?

 

[neptronix]

No, geared means it has an internal planetary gear reduction.
Having a rear set of gears makes it a rear motor.

30a max means just that; short bursts. Not a mile or more of riding at 30a!
at 25mph+, you will be guzzling energy due to aerodynamics and will be constantly over the 15a limit, think 20-25a.

That battery will technically do the job but it won't last long and it will voltage sag like crazy. I have heard of some people dropping 5-10 volts on a ping when they hit the throttle. That is not acceptable for a high voltage setup in my opinion.

The 'C' rating of a battery relates to how much amperage per ah it can put out. Lipos are 15-90c, good lifepo4 is 3-5c, and those pings are in real life usage, 1-1.5c.

That is why a 15ah ping battery pack is almost maxed out at 15amps, anything above and beyond that is a bonus. It's like driving a car at redline at all times.

 

[MadRhino]

Your expected range is very short, but your expected power is a tad above what can be expected from your components. Your motor is a small geared hub, It may be able to climb a 8% grade for a mile, but won't last very long doing so. You'd better be ready to pedal hard to help it, to give it a chance to survive.

To make it clear: Your planneed setup works, not as powerfull as you expect, and with fragile reliability. It will rely on your human power to make it, or else the Ping will wear fast, and you'll experience the smell of the melting gears sooner or later.

Nevertheless, many of those who are after performance, started in the very same circumstances as you are. Nothing like having to climb everyday, to make you learn what is needed to achieve performance and reliability.

 

[RallySTX]

And yes, you should get a 48 volt controller, because that one will have the low voltage cutoff in the right spot. What Madrhino meant by middrive is what we also call outdrive. This is a small RC motor under the seat area, driving the chain for the rear wheel, or a seperate one on the other side. Hub motors like the ones we have been discussing come in two basic configurations. I bet you are getting that idea by now though. The first is a geared hub, like the one you probably own now. It has plastic internal gears that power it. The other type is called Direct Drive, or DD. They have magnets that make the magic happen. Infineon is the original manufaturer of electronic devices like controllers. Lyen is a site user, simply search for his posts via the search bar. He sells modified controllers, as does Cellman, and Ecrazyman, if I'm correct. That doesn't mean that they're bad, just the oposite in fact! These are but a few of the GO TO GUYS, you will see on this site. Whatever you decide to do, be careful, we want to see and read about your experiences, not your untimely demise! If in doubt, ASK! Here there are no stupid questions, just stupid people like me who forget to ask. Good luck.
Brian L.

 

[John in CR]

You have more than enough battery. The only question is the current it can deliver in that steepest segment of the hill. You definitely want a programmable controller, so you can dial things in just right and not trip the current protection on the battery's BMS. That is going to require some amount of trial an error. Buying some stock controller will either leave performance on the table and struggling up the last part of the hill, and bogging down on a hill stresses the entire system and is very inefficient, OR the controller current limit will be too high and trip the BMS over-current protection leaving you on the steepest part of the hill needing to stop to reset the battery pack. Starting from 0 on the steepest part of your route is what you want to avoid at all cost. If it's programmable then you dial it in with limits just below the trip point on the battery's BMS to maximize the motor power up that last steep section without issue.

Buy yourself a motor in wheel. Check the for sale section, Methods has a variety of good motors. Then pick up variable voltage programmable controller, a throttle, and an ebike tester from Lyen, also in the for sale section. Add in the Ping 48V15ah and you're in business. Then you have a motor and controller that can grow with you, so when you want more performance later, just add a 24V15ah or 36V15ah Ping pack in series with a diode in between to protect the packs from voltage spikes.

 

[MadRhino]

...What Madrhino meant by middrive is what we also call outdrive. This is a small RC motor under the seat area...

...Or a 40hp Agni95.

 

[torker]

You might just get a decent battery first. Most 36 v controllers will handle 48v so yours might work on 48v. If it will then you will be amazed at the difference going from sla probably sagging to lvc . You will actually be adding almost 20 volts since the Lifepo will have around 50 v That alone will really wake it up and may approach the limits of that motor. I wonder if the Cohnismotor Lifepo batterry would be any better than a ping? It is cylindrical cells instead of pouch cells like a Ping. Maybe someone will chime in. http://www.conhismotor.com/ProductShow.asp?id=46

Wow just realized I revived a 2 yr. old thread Doh. I was searching for info on the Cohnis battery and decided to reply
Brainfade