Beginner controller/ cycle analyst questions.

[Kleinbottled]

Let me start saying I'm new to this stuff. I've been reading (mostly here at ES) about E-bikes for a little over a week. It's been getting ALL my spare time. First project is already underway with a battery en route from Li Ping 48v 15ah. Motor will be of the 600-1000w 10t geared hub motor variety. I think I sorta have a bit of an understanding of the motor/ battery combination. However, when it comes to controllers and cycle analysts my head starts to spin a little. I've got a few questions. Links to threads or w/e kind of answers you all can give will be much appreciated.

So I get that my 15ah Ping battery likes to be discharged at <30A continuous ideally. 25A gives me just under 1000w output from the motor according to the simulator at ebikes.ca. This seems just about perfect. Motor should be safe and the battery happy, also being within local law's 1000w limit is a bonus. The obvious thing to do would be the select the appropriate 48v 25a controller and call it a day. But its not that simple is it? I want to run a cycle analyst. If I want to be able to drop the current limit with a CA I want one that has a direct connect ability with the controller right? I have a section almost 2 miles long on my commute that is ~6%. If i wanted to baby my motor/battery up this climb is it better to limit the current thru the CA ( maybe 18-20A ) or to back off the throttle a little? Is the 'speed limit' on the CA controlling throttle setting or current limiter or...?

While we are limiting current it brings up the question of going bigger. If i'm trying to accelerate with traffic downtown I might like to have the little extra shove 30A would give me. Since its not sustained that should be fine for battery/motor, but now we need a 30A controller. Cost not a factor, Is there a significant drawback to using a 30A or 35A controller and limiting it to 25A most the time through CA? Is it hard on the controller to do this? or maybe easier? i.e. reliability concerns. Is it more resistance? enough to matter?

On sort of a side note, the idea of a 'soft-start' seems pretty good. Especially if you have friends that are going to want to try your bike,. But also just to pamper your setup. Would a smooth throttle finger be just as good provided I'm not loaning the bike out? I Know the 35/50a BMC controller has a soft start jumper. I hear the controllers Cellman used? to sell sorta had one built in. What about the ones that come with his mac kits now? Do the Lyen edition controllers have this capability?> Any others controllers do this? Or other ways to implement some sorta of protection from the ham-fisted? Just curious. Thanks

 

[dogman dan]

My approach would be to get a controller from cellman, so you get that soft start. His stuff has been matched up with the motors for the least potential problems. Get one up to 30 amps max. You won't pull 30 amps all the way up that hill, 6% is not so bad. So your ping battery will be fine. short hills much steeper will also be fine. Most likely, you'll see some spikes of high amps, but grinding up a steep hill, you pedal a bit and amps will drop below 20.

You might want more amp limiting if you chose the 6t motor. But one of the beauties of the slower windings is that because they don't waste as much energy into heat on hills, they don't require amp limitng as much. The slow windings hit their back emf limit, and simply stop sucking amps and truning it into heat sooner.

So you'd be fine with the 30 amp cellman controller, and if it doesn't come with a CA plug, just ge a stand alone CA. You are on the right track.

 

[Kleinbottled]

Even 8t would be ~30mph at 50+v on these 700's. If I feel the need to go that fast on my v-brake road bike maybe ill make/buy a 60v pack . Kit is ordered more or less to dogman's specs. Not that I didn't do plenty of my own research, just ended up deciding his way was the right way. Controller is gonna be a 9x4110 fet Lyen edition set at 25A. Kit through Ilia at Ebike-sf. Talked to him on phone and his reputation for being great to work with seems well deserved. He even dug around to find a V-brake ready rim to build for me.(not on his order sheet) Ordered a frame bag from falcon EV after I read that a member here stuffed a ping 48v 15ah in one successfully. Should work for me too, my frame has more space. Can't wait for the parts to start showing up.

I'll be sure to take some pictures to post for you guys. Maybe start a proper build thread. Don't see a whole lot of road bikes on here, some but not many. When I start commuting I'm going to start keeping track of costs. Hopefully I can save enough money in gas to cover my E-bike hobby. Fingers crossed but not holding my breath. Some one once told me some of these components aren't lifetime guaranteed.

P.S. How come ebikes make electricity so awesome?

 

[alfantastic]

Just to give you a heads up on the performance a 48v 15Ah Ping delivers, with a Cellman MAC 10T and his 9 fet 30A controller.
All his latest controller have a direct plug-in CA connection.

Top speed on the flat - 27mph
The controller does appear to be programmed for a soft start. You won't be winning any off line burn-outs, but it allows for a lovely smooth start, and the torque pull from around 10mph is amazing.
No fears of this motor bogging down to overheat stage, unless the hill is 15%+
It'll eat that 6% hill you mention for breakfast.
Ping's 48 15Ah pack custom split into two parts fits snuggly into the Falcon EV bag and fits like a glove into a 19" MTB frame. Controller fits in too
I wouldn't bother limiting either speed or amps with the CA. I found it to be a bit too crude at doing this. Although I personally don't use the controller speed switch function, it does work nicely at limiting the speed.





Click link below for close up of battery pack:

View attachment 1

 

[Kleinbottled]

That's a clean looking build, did you split the pack or did ping do it for you? 27mph is plenty fast. I was getting the exact same number on the simulator before i made my choices. Ill have to back off a little to crusie. Not trying to waste all my charge pushing air aside. I need that juice to push my arse over the hill hehe. To me, the idea of a bicycle pushing someone up a hill at 20mph is somehow more amazing then the idea of going fast on the level.

 

[alfantastic]

That's a clean looking build, did you split the pack or did ping do it for you? 27mph is plenty fast. I was getting the exact same number on the simulator before i made my choices. Ill have to back off a little to crusie. Not trying to waste all my charge pushing air aside. I need that juice to push my arse over the hill hehe. To me, the idea of a bicycle pushing someone up a hill at 20mph is somehow more amazing then the idea of going fast on the level.

Ping split the pack for me for an extra 10$. You couldn't get a more perfect fit in the frame bag, and I have added plenty of foam padding too for shock protection.
I started off a few years ago with a ready made 24v bike limited to 16 mph. It was a bit lame on the hills too, but still gave me a massive grin factor.
You seriously soon get used to the power and want more, so I spent around a year planning my first build you see in the picture.
It is plenty fast for me, but as I say, you will get used to the power. I would recommend over-speccing a build and using a speed switch to tame it.
20 mph up that 6% hill will seem like nothing after a few rides, believe me :lol:

BTW, Cellman confirmed via e-mail a few months back, that the first 2 speed settings on his controller's speed switch, desensitizes the throttle response slightly, improving throttle control on low speed maneuvers. Speed setting 3 is maximum welly.
His controllers really are the mutt's nuts

 

[Kleinbottled]

I believe the Motor/control combo I've selected could push my bike to almost 40mph with a hot 72v lipo pack. But honestly if i want to go that fast its gonna be on something with suspension and more rubber on the road. Oh and disk brakes. I'm not promising I wont lust after more power,.. seems to happen to everyone. It just cant happen on this frame; for safety sake. This build is all about commuting cheaply, stealthily, low power, long-ish range, and hopefully getting some life out of the parts. Ill make a second bike for going fast and having fun if I love it as much as I think I will.
A lot of you ES members seem to have started with low voltage and SLA's. I feel privileged to be starting with 20+mile range lithium and a 25+ mph. It still seems like something from the future. Like it shouldn't be possible.

 

[gurshark]

My approach would be to get a controller from cellman, so you get that soft start. His stuff has been matched up with the motors for the least potential problems. Get one up to 30 amps max. You won't pull 30 amps all the way up that hill, 6% is not so bad. So your ping battery will be fine. short hills much steeper will also be fine. Most likely, you'll see some spikes of high amps, but grinding up a steep hill, you pedal a bit and amps will drop below 20.

You might want more amp limiting if you chose the 6t motor. But one of the beauties of the slower windings is that because they don't waste as much energy into heat on hills, they don't require amp limitng as much. The slow windings hit their back emf limit, and simply stop sucking amps and truning it into heat sooner.

So you'd be fine with the 30 amp cellman controller, and if it doesn't come with a CA plug, just ge a stand alone CA. You are on the right track.

Dogman, this is almost my exact spec for 1st build, except I am thinking about the 8T MAC from cell-man. My commute is 18 miles one way, with a 3-4 mile 4-6% grade at the end. Do you think 8T will be ok with 48V 15Ah Ping, 9FET from cellman? Or would you recommend 10T? I'd like a few extra MPH, but don't want to stress my battery/motor on hills. Other parts of Portland have some bigger hills, but nothing much bigger than 6% (that I would want to go up). I'm on the fence: 8T vs 10T. Cell-man says 10T is 25mph, 8T is 30mph with 48V 15ah ping. Advice?

 

[alfantastic]

I would definitely go for the 10T and 30A 9 fet controller.
Look at the ebike simulator between BMC V2 Torque (equivalent to 10T) and BMC V2 Speed (equivalent to 8T)
The 10T will be much kinder to your Ping than the 8T on a long 4-6% hill, plus you will have a little leeway for anything steeper.
The speed difference between riding the 10T and 8T on a hill isn't much different, because you will hit the current limit on the controller with the 8T very quickly, blunting performance.
My next build will be an 8T, but I'm going to use Cellman's 40A 12fet and A123 triangle pack, as his battery will be able to provide the current rather than kill a Ping.

 

[Kleinbottled]

Just a heads up Alf, Cellman told me he was out of the cells he makes into triangle packs. That's what I wanted initially too. If he starts making em again let me know. Yeah I was looking at the Sim also,.. With MTB frame at 25mph you will see ~29kw/h consumption. At 30mph it goes to ~45kw/h. Fast wind could work, I'm guessing, but you might have to show some restraint and/or help pedal more. Range could a factor. With 10t you could probably motor full throttle with minimal pedaling and still make your 18 miles easy. Is your controller 63v Fet (3077) or 100v(4110) or something else? I think I heard someone talking about 80v fets. Well if they are higher than the 63v type you could save up and get some variety of higher voltage pack for playing around with. 4s more LiFePO4 would be 70+v off the charger and that's 30+mph from the 10t. Learn to play with lipo and your 10t might see 35+ but that's about when people start breaking things a lot on the MAC/BMC it seems like.

 

[alfantastic]

Mine's Cellman's 3077 variety, but I don't plan on going beyond 48v anyway.
I get around 25 miles from my 15Ah Ping at the moment, with plenty of hills and nearly all throttle, so would expect 15-20 with an 8T, meatier controller and only 11.5Ah.
Range isn't a problem for me as I use the bike for recreational use only. Coupled with one of Paul's higher amp chargers, then recharge time would be minimal.
I reckon 2000w on the MAC is on the limits of reliability, even with Paul's soft start controller configs. I feel the sprag would be the first to go above this power level.

LIPO...... mmmmmmmm....... maybe one day

 

[Kleinbottled]

Ahh the range/speed/voltage comments were more directed at gursharks questions. I just wanted to let you know about my inability to order that triangle pack from cellman. Should have made that more clear.

 

[alfantastic]

Ahh the range/speed/voltage comments were more directed at gursharks questions. I just wanted to let you know about my inability to order that triangle pack from cellman. Should have made that more clear.

Thanks for the heads-up. I did read somewhere on this forum that A123 Systems are having a few problems.
Hopefully Cellman will be able to supply in the near future, coz I gots to have that triangle battery

 

[gurshark]

Just a heads up Alf, Cellman told me he was out of the cells he makes into triangle packs. That's what I wanted initially too. If he starts making em again let me know. Yeah I was looking at the Sim also,.. With MTB frame at 25mph you will see ~29kw/h consumption. At 30mph it goes to ~45kw/h. Fast wind could work, I'm guessing, but you might have to show some restraint and/or help pedal more. Range could a factor. With 10t you could probably motor full throttle with minimal pedaling and still make your 18 miles easy. Is your controller 63v Fet (3077) or 100v(4110) or something else? I think I heard someone talking about 80v fets. Well if they are higher than the 63v type you could save up and get some variety of higher voltage pack for playing around with. 4s more LiFePO4 would be 70+v off the charger and that's 30+mph from the 10t. Learn to play with lipo and your 10t might see 35+ but that's about when people start breaking things a lot on the MAC/BMC it seems like.

Thanks for the reply Kleinbottled. Here is Cell_Man's response to my 10T vs 8T question, given my aforementioned commute distance and hills: "The controller determines the max current draw you will pull from the battery and a faster motor will only pull more current if you actually use that higher speed. 48V 15Ah is enough to do 18 miles at about 25mph, or the max speed of the 10T, but probably is a little short to do the same distance on the max speed of the 8T of a little over 30mph.

You don’t need to use full throttle all of the time and there is a programmable 3 speed switch that you can adjust to whatever you wish. If you use an 8T on speed 2, it will behave very much like a 10T on speed 3. It is a good idea to use a Cycle Analyst, that way you know the complete situation with regards battery remaining and power used."

So I guess I could limit the speed to get the full 18 mile range, and not limit it for shorter, faster (more fun) rides, but I still wonder if the 8T will heat up too much on the long uphill, or stress the battery too much, even if I limit the speed with the 2nd setting of the speed switch. Any thoughts?

Let me just say that ES is an awesome resource, and I appreciate all of the knowledge and sharing that bounces around here. What a great community.

 

[Kleinbottled]

Gurshark,

I'm far from an expert but here's my two cents anyways. 10T will be more kind too your ping like Alf said. 8t motor will draw max 30a current more of the time. Not so much on hills (where both motors would be maxed), but on the flats and accelerating. On the flat land, 25mph will draw about 15 amps (or 1c) from your battery. This is a comfortable discharge rate for lifepo4. 31 mph is ~29 amps right at the battery's maximum discharge rating. Also 10t stops drawing full current at full throttle around 21mph; any time you are above that your battery is in happy land. 8t pulls the full 30a at wot till about 30mph; meaning anytime you are full throttle you are full amp draw. I would suspect your battery wont last as many cycles on an 8t as a 10t. Now how much shorter I can't even guess, it would depend a lot on how you ride. If you get 900 cycles instead of 1000 maybe who cares eh?> Dunno, maybe someone with more experience can chime in here.
My plan for when i wanna go 30+ on my setup, which i probably will someday, is to buy a smaller capacity, higher voltage, higher discharge pack, probably based on inexpensive RC lipo. A 10t can take one well into 30-35 with higher voltage packs. And then I can swap my ping back in to have my ideal commuter. Don't think you should worry too much about cooking the 8t on 30 amps if you have your heart set on it. Battery might take a little more abuse though.

 

[999zip999]

Love the Ping batteries at 15ah or bigger. Also get the 5a charger. Li ping is great nice guy.
The three switch is great and get all the extra's C.A. ect. all wired up now. It's the shipping that's costly.