Long Distance Ebike Design

DrkAngel said:
jkbrigman said:
- What kind of onboard charger?
Ultimate lightweight charger! ... ?
Experimental!! ... hypothetical!
26s LiCo specific
120V AC through a bridge rectifier supplies a full wave rectified (slightly rough*)
108VDC - 15A-20A, from any standard 110V AC outlet
(Current regulated through BMS ... recommended?)
108V ÷ 26banks = 4.15V
Looks ideal for LiCo cells

LiFe cell count not figured ... but should be applicable also

* Do not add capacitor!
Might produce an initial, damaging, surge of ~170V !!!
I've been building DC led lighting using rectified AC through LEDs in series.

s30 LiFe = 96V (108V charger)
108V ÷ 30banks = 3.60V = safe-maximum charge voltage

15A AC outlet provides ≤1500w charger at ~≥90% efficiency.
20A AC outlet provides ≤2000w charger at ~≥90% efficiency.

Requires AC power cord and ≥20A bridge rectifier (Available for ≥$2)
Current regulation regulated by charge C capacity, BMS or other?
Gauge and length of AC wire could "trim" current?

All charge voltages are based on 120V.
115 or 110V might necessitate alternate cell count. eg. s26-29 AC rectified charger + s1-s4 charger
 
jkbrigman said:
RLT said:
300 miles a day? Pretty ambitious on a bicycle, even a recumbent, just the physicality of riding.

I remember just before I 'left' this forum for other interests, six years ago, Justin Le rode his E-bike across Canada, Coast To Coast. So there is a guy with 'real world experience'.

RLT: You're right, 300 miles is extremely unusual. To me, it's just a number, but something I wanted to think out loud about. The holy grail for me is a "100 mile bike", which really means a 110-120 mile capable machine (you need a little overhead) down to 80% depth of discharge. To be perfectly honest with you, this is a future build I'm thinking about, so I'm trying to make some ideas and variables more concrete before I attempt this.

I don't think of a 100 mile ebike as anything unattainable or mystical: JennyB has documented 100 mile rides on her road bike in which she's using the electric propulsion as only a hill assist. That's a valid "use mode" and something I think is feasible if the bike is light enough (and you aren't carrying too much onboard cargo). If you start carrying 50 lbs or more, you start wanting electric help even on the flats.

And BTW: You are right, Justin has done it (VERY well!) and I have pored over every word in his thread. I'll hunt it back down and replace this sentence with a citation of his thread. I'm hoping, hoping, hoping that somewhere along the way on this thread, Justin will offer some comments!

Alan B said:
You might re-read Kingfish's threads, he's done a lot of this. He's gone toward 2wd with a trailer to carry a lot of batteries, but he's tried many things along the way.

Alan B: You are right, and thanks for the reminder, I'd forgotten Kingfish's threads. I'll edit this posting later and replace this sentence to cite his thread.

Hi, just wanted to add something to this thread. I learned quite a few things browsing trough.

Here's my take. My setup is pretty basic - a mountainbike with a DD 500W limited to 250W &25kph for conformity within the EU and 50V/12Ah EM3EV NMC battery. I use it mainly to get me started from a light, on hills and if the headwind is very strong. The tires are nothing special and the bike doesn't have anything particularly lightweight except for the aluminum frame. With this I do on average 140km - 87miles.
In my use case in order to pass the 100 miles mark I'd just need to buy the bigger 18Ah triangle EM3EV battery. Add some more batteries on the back and 200 miles are possible easily. Also if I did a new build I'd use a smaller motor as the 9c-equivalent is a bit heavy, add low drag tires, replace the suspended fork with something simpler/lighter; for your use case I just think you need more power in order to hit the range due to the higher target speed, so with my bike you wouldn't hit 87mi, but maybe 60; with the 18Wh battery 100mi should be achievable assuming you might pedal a bit.

My 2 cents
 
This winter, if I will not have found already a gas motorbike to convert to Electric and put to good use
the 7 Leaf modules I bought, I will mount 2 Leaf modules (4s1p) on the rear rack of this:

Bici_Energy_bike_torpado1.jpg


... in practice I will obtain an e-bike that is reasonably confy when riding and is capable of real
trips lasting up to 100 - 150 km with reasonable speed and light to no pedaling.
33V full charged with 33Ah pack .... with a standard 11Ah pack I'm already doing 50 km per charge ...
The best thing is that bike+battery would have a cost below 599€ (all bought new).

have good luck and fun!
 
jkbrigman said:
And BTW: You are right, Justin has done it (VERY well!) and I have pored over every word in his thread. I'll hunt it back down and replace this sentence with a citation of his thread. I'm hoping, hoping, hoping that somewhere along the way on this thread, Justin will offer some comments!

If you wish my friend!

It looks like the discussion here has already covered most points really well so here are the tidbits I'd emphasize from my own experience

1) Recumbent: This is a total no brainer and glad to see you have already gone this way. I went in a semi-recumbent (recumbent seat sitting on the back of a stretched MTB frame) which gave the comfort advantages of a proper seat an backrest for which I was ever greatful, but it lacked the aerodynamic advantage you get from a true recumbent bike or trike. Both tadpole trikes and LWB recumbents have plenty of frame area for securing batteries and gear, but a SWB would be a nonstarter of a platform as a distance platform unless you wanted to pull a trailer. You can sit on a regular upright bike for 8, 10, 12 hours a day, tons of people do, you just wonder why when there is such a better alternative.

2) Mid-drive vs. geared hub vs direct drive hub: Here I would still be partial to a direct drive hub motor. The freewheeling nature of a geared hub doesn't give you anything, since I can guarantee you'll be using the motor 100% of the time except when you are going downhills, and then all the freewheel means is that you aren't benefiting from the regen that a DD could provide you. And the lighter weight of a geared hub is totally lost in the mix when you have 2+ kWhr of battery weight and all the gear. It would work, it's just that the usual advantages of a geared hub (better torque/weight ratio and freewheeling) aren't as valuable in this context, and the downsides (increased risk of mechanical gear or clutch failure) are all the more pressing. A mid-motor has its temptations especially in steep hilly terrain, but I really like having fully independent pedal drives and motor drives. That way if the chain snaps, the derailleur hanger breaks off, a chainring bashed etc. you can still motor along fine. On a mid-drive, a failure like this is pretty catastrophic to your progress. But you could no doubt make any of these systems work and all will have more or less equivalent efficiency at the end of the day.

3) Batteries: Definitely use the high Wh/kg energy cells, any of the samsung/panasonic/LG/Sony 2.9Ah 18650's would be fine. This way a 2kWhr battery pack is still a manageable size and weight, and 2KWhr is about the minimum you want for a 100+ mile range with some margin. You're not going to pull more than 1kw from any free/shared/public outlet, which means you won't need to support anything more than a C/2 charging rate, which means there is no need at all for high power cells like A123's or anything like that; you just wind up with a much heavier battery. I took about 1.4 Kwhr on the cross canada bike, and just under 2Kwh on the cargo bikes we rode Vancouver -> SF last year. Couldn't imagine having much less in either case.

4) Chargers: Regardless of what you do for chargers, hook things up as permanent onboard chargers already wired together and to your batteries so that you just have a single extension cord to plug the bike itself in. This way when you pull over for a lunch stop you don't have a tangle of chargers, batteries, power bars, and such to connect together. It raises eyebrows the wrong way and it makes you less inclined to take advantage of short 20-30 minute stops. You want the least amount of overhead to plug in and profit from the first exposed outlet you can find. Also, having a ~50ft extension cord gives a lot more flexibilty to find outlets in one place but position your bike somewhere else that is more convenient to lock up or keep an eye on.

5) Fairings: I have almost no experience of proper fairings, but I have heard from those that do that they can be quite noisy, amplifying every rattle and bump on the route. And overall ambient noise is something that plays into pleasure/pain factor of long distance ebike touring. But a fairing that keeps you dry when riding in the rain, that would help reduce one of the greatest miseries of all when touring on 2 wheels and would be so very well worth it.

6) Redundancy: Always have a backup motor controller and throttle with you, so that if anything goes bonkers with the electronics, or you plug in the pack with reverse polarity and fry the mosfets etc. you can always swap in the new controller and throttle and have the ability to keep powering along. It should be sensorless too so that you aren't disabled by possible hall signal issues. Similarly, the battery should be several independent packs each with their own BMS all wired up in parallel, rather than one single large battery. That way you can suffer through a battery/BMS issue and still have plenty of useable capacity from the other unaffected packs. Things are getting more and more reliable with ebike gear, but it's still not at a point where I'd bet everything on a single system.
 
Sorry. Dupe post deleted.
 
justin_le said:
If you wish my friend!

It looks like the discussion here has already covered most points really well so here are the tidbits I'd emphasize from my own experience...

The king has spoken!

Great points, Justin. I especially like your thoughts on the onboard chargers. I hadn't thought of that, in terms of how simplicity in charging can make or break you. One thing I worry about (I'm working with jkbrigman on planning our own XC trips….eventually) is water ingress in the chargers. If I have them in my backpack, I can be sure they're protected, but on the bike somewhere they're bound to fill with spray when things get wet and wild. I saw Troy, who is currently doing a record breaking XC trip, did a good job of sealing his controller so that's something I'll have to look into.

The other issue you brought up which I agree is really important is considering how much power you can pull. Troy is using coke machines as his own personal cross country charging infrastructure, which is working great. I believe he said he's working with a 1400W charger, though I don't know if he's using it to its full potential. I'm considering running two 48V 20AH NCM packs with 10A chargers, so something like 600W charging each. I'm just worried if I plug in 1200W while a coke machine compressor is running, I'll blow the circuit and some gas station owner is going to be pretty pissed. I wonder if anyone has a good estimation on what a good safety margin is for pulling power out of a multi-use wall outlet like that?
 
LockH said:
Wow. Redundancy:(used to making/having Alt. Plans/Options, "back up plans" - hehe just maybe never so succinctly... :x All words from the Big Cheese (Capital J) 100 percent I'm sure.
 
Justin, thanks for the good word. I'm either working on those points or planning to for the future. it's great to know I'm on the right track!

BTW: I found mrbill's website:
http://mrbill.homeip.net/index.php

The image showing 4.8Wh/mi caught my eye:
http://mrbill.homeip.net/albums/powerPursuitBuild/single-image/20061202-powerPursuitBuild23-photo.html#anchor
 
Those wishing for the ideal onboard charger will soon be satiated I think.

I agree with Justins comments on KISS the chargers and cords situation. I'm still using 300w chargers, and on a tour I drag two of them out and plug them in. Each one charges a portion of my 25-35 ah pack. It does become tiresome if you keep having to bring it all out over and over. At least a 25' cord for sure, so you can get out of the way while charging.

But I haven't worked out the right place to put them on the bike to keep them dry, and ventilated in use. So I'm stuck with the extension cord to the free range plug, then usually two chargers sitting next to or on top of the bike, looking and sounding like I'm using more power than I am.
 
jkbrigman said:
BTW: I found mrbill's website:
http://mrbill.homeip.net/index.php

The image showing 4.8Wh/mi caught my eye:
http://mrbill.homeip.net/albums/powerPursuitBuild/single-image/20061202-powerPursuitBuild23-photo.html#anchor

I ran over Mr Bill with my ebike on the highway, and it must have been faster than he expected, because at 100mph he only had time to say "Oh No..." The playdough sprayed everywhere, so that website must be a clone.
 
dogman said:
I agree with Justins comments on KISS the chargers and cords situation. I'm still using 300w chargers, and on a tour I drag two of them out and plug them in. Each one charges a portion of my 25-35 ah pack. It does become tiresome if you keep having to bring it all out over and over. At least a 25' cord for sure, so you can get out of the way while charging.
I'm planning a girlfriend bike type BMS / charger setup for use with LiPo cells. Something that doubles as an Low voltage / battery level indicator when on the road, and an automatic CCCV charger / ballancer when charging. I'm planning to use a very dumb charger that basically delivers a voltage higher than the pack (a transformer with some diodes will do).
I think what you want for a girlfriend / grandma setup is what Bosch delivers with their ebike: a charger box that connects with a single 2-wire plug to the pack. Ballancing and
battery level indicator should all automatic and located in the pack.
 
Lebowski said:
dogman said:
I agree with Justins comments on KISS the chargers and cords situation. I'm still using 300w chargers, and on a tour I drag two of them out and plug them in. Each one charges a portion of my 25-35 ah pack. It does become tiresome if you keep having to bring it all out over and over. At least a 25' cord for sure, so you can get out of the way while charging.
I'm planning a girlfriend bike type BMS / charger setup for use with LiPo cells. Something that doubles as an Low voltage / battery level indicator when on the road, and an automatic CCCV charger / ballancer when charging. I'm planning to use a very dumb charger that basically delivers a voltage higher than the pack (a transformer with some diodes will do).
I think what you want for a girlfriend / grandma setup is what Bosch delivers with their ebike: a charger box that connects with a single 2-wire plug to the pack. Ballancing and
battery level indicator should all automatic and located in the pack.

I am convinced that is the right path: Informatics display belongs on the bike with the cells, not on the charger. Charger itself should be big, badass and able to deliver as much power as it is called to deliver. Charging with an R/C charger is a very difficult thing without spending huge money on connectors and wire. You save big money on chargers by keeping balancing internal to the battery enclosure.

Make sure, Lebowski, that you include "charge cutoff" in your design. Then the ebiker can use almost any good power supply of the right voltage to charge! It would be awesome to use my Meanwell LED supplies full-time with my packs, having balancing internal to the battery enclosure. What you are describing could work with anything from a Cycle Satiator to a simple linear power supply.
 
Here's ~1.2 kwh worth of 2500 mah 18650 in a 12s12p mocked up in my Long Wheelbase Long Distance build. I'll be starting a build thread shortly after I get my 9C clone 26" rear kit which according to Ebay is scheduled to get here on Saturday.

dh1000_a.jpg


I'm using these type of 18650 cell spacers, I already have the cells and will be assembling the battery when I finish testing and matching them. If I staggered the spacer blocks to fit the battery more closely to the frame I could probably get 3 kwh in there without trying too hard.

18650-battery-holder-cell-bracket-for-DIY-battery-pack.jpg


For suspension I'm going with Schwalbe Big Apples, the widest that will fit in the frame, I have 20" and 16" Big Apples on my Grocery Getter bent in my sig and they do very well at smoothing out the road in addition to having lower rolling resistance than you would think, 26" and 20" with even more weight on them should work even better.

A Cycle Analyst V3 is planned and I'm going to use the potentiometer option as a variable current limit as well as current based throttle control and pedelec as well I think.
 
I'd say wire in an additional + and - directly to the pack bypassing the BMS. This could get you out of a jam quickly if it failed.

The schwalbe tandem tire would be best suited for your load weight.
 
Jonathan in Hiram said:
Here's ~1.2 kwh worth of 2500 mah 18650 in a 12s12p mocked up in my Long Wheelbase Long Distance build. I'll be starting a build thread shortly after I get my 9C clone 26" rear kit which according to Ebay is scheduled to get here on Saturday
...(photos removed for brevity)...
For suspension I'm going with Schwalbe Big Apples, the widest that will fit in the frame, I have 20" and 16" Big Apples on my Grocery Getter bent in my sig and they do very well at smoothing out the road in addition to having lower rolling resistance than you would think, 26" and 20" with even more weight on them should work even better.

A Cycle Analyst V3 is planned and I'm going to use the potentiometer option as a variable current limit as well as current based throttle control and pedelec as well I think.

Jonathan that is a Beautiful Thing, man. I expect you'll do a build thread but please, keep us updated on your progress in this thread, pics and all. I'd like to hear back from you how well the 9c fits in the dropouts on that bad boy.

PLEASE bring-on the Wh/mi numbers. I intend to compete with any and all comers on the lowest possible Wh/mi. Efficiency is the key to shortening the run/charge cycle.
 
I got my kit in but since I'm still working on the battery I haven't done anything with it beyond take a couple of pics.

Battery construction in progress.

9_C_motor_battery_teaser.jpg



Rear motor with 26" rim

9_C_motor_box.jpg


Speed controller.

9_C_motor_speed_control.jpg
 
jkbrigman said:
Justin, thanks for the good word. I'm either working on those points or planning to for the future. it's great to know I'm on the right track!

BTW: I found mrbill's website:
http://mrbill.homeip.net/index.php

The image showing 4.8Wh/mi caught my eye:
http://mrbill.homeip.net/albums/powerPursuitBuild/single-image/20061202-powerPursuitBuild23-photo.html#anchor

That last image was one of my first e-bike rides when I was mostly pedaling. A more realistic figure is something between 8 and 15 wh/mi (5 and 9 wh/km) if you pedal. If you look through the data table for each event in my bike blog, pay attention to the distance, climbing, average speed, wh/mi, and the division of human and motor energy directed to the driven wheel. My rides are usually very hilly by most cyclists' standards, but I have done a few flatter rides.

http://mrbill.homeip.net/bikeBlog.php?latest

To assess the baseline efficiency of my bikes under somewhat controlled conditions I recently rode twice the same route on two different bikes using only motor power.

http://mrbill.homeip.net/bikeBlog.php?latest#effortlessRides.2014.08

My longest one-day ride:

http://mrbill.homeip.net/bikeBlog.php?2014#davisDouble.2014.05.17
 
I got my battery box about 90% built, batteries and controller installed, all the motor and throttle/brake wiring come in through a hole in the middle of the bottom of the box. I still have the removable side cover to make. At t he moment I'm running 12s12p 18650 cells and I left room and mounting options inside the box for 2 more 12p strings to make a total of 14s12p when I can scrounge up more cells. This is just a trial fit, everything will come out again for final wiring and painting.

Next time I will build the battery box first and then put together the batteries, I could have got more cells in there with better planning.

The motor appears to be a 2807 9C when I measure the no load RPM and cross check with the Grin simulator. It was the Ebikeling 1000w 48v DD kit from Ebay and so far everything seems great other than a few loose spokes.

Sooner or later I'll get around to doing a build thread..

battery_box_closed_side_whole_bike.jpg


battery_box_open_side_installed.jpg


battery_box_closed_side.jpg
 
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