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Hey guys, as mentioned on our homepage last week I'm planning to ride an electric bicycle right across Canada from Vancouver all the way to Halifax now, about 6500+ km, and want to meet up with as many of you along the way as possible. I actually left last Tuesday for a trial run along Vancouver Island, riding from Sooke to Nanaimo and back here in order to field test the system, had some serious breakdowns on the way so am now back at my shop rebuilding the rig but I'll be leaving for real tomorrow morning (July 31st).

A bunch of pictures and descriptions of the setup to follow.

The bike itself is an Xtracycle conversion that has a recumbent bike seat secured to the free radical, so it rides in a semi-recumbent position with a very comfortable posture and still has most of the storage capability of an Xtracycle. In place of the regular seat tube I've stuck another set of handlebars that links up to the front handlebars. In a pinch, I can slide the 2nd handlebars out, remove the linkage, put the regular seat back in and be back to an old fashioned upright bike, and then the recumbent seat at the back can be used for a passenger. Who's to say I can't pick up hitch-hikers along the way!

Go Justin, go!

Keep us posted on your progress. Hope you make it before winter...

I wanted to be able to do about 100-120 km per charge, and with a heavy setup like this that meant at least 1.4 KWh of battery capacity, figuring about 12 Wh/km, assuming a cruising speed of some 35-40 kph. So with a 36V system that meant getting on the order of 40 amp-hours of battery capacity, and it all had to fit nicely on the frame to leave cargo space in the back for all my gear.

Obviously, the lightest batteries for the job are Lithium Polymer, so that's where more than half the energy is stored. I built what should have been two 12Ah lithium polymer packs, each out of 20 6Ah 6C rated cells. The cells are enclosed in a glued-and-screwed together black ABS case and they are shaped to stack on top of each other along the seat tube inside the front triangle.



Linking the cells together is only a small part of the picture of building up a custom lithium battery pack, wiring the BMS is another job unto itself. One thing I always find disconcerting is that the BMS needs a connection to each individual cell, and these are usually done with thin gage wires that feed and loop around the pack, and in the event that there is any heating or mechanical pinching or whatnot these wires could short together and spell doom for the battery. So I soldered a self resetting polyfuse right at the source of each cell sense lead.



Also, selecting a BMS can be tricky business on a setup that does regen. Most of the BMS circuits we have come across recently have a single port that is shared by both the charging and the discharging leads, and this means that during regen the BMS can cut out and prevent any current flowing back into the pack, and with a regen controller you don't want this to happen. Fortunately I was able to salvage a couple of old BMS circuits with separate charge and discharge ports from some of our trial lithium batteries from a few years ago.



The finished pack is capped off with clear polycarbonate windows so you can see the juicy insides but it is still mostly protected from the elements. Unfortunately, as always seems to be the case, as soon as you attach a BMS to a bunch of lithium cells you loose about 10-20% of the capacity no matter how carefully you try to balance all the cells. So in practice these packs give just a little over 10Ah before the BMS shuts off.

In addition to the lithium polymer pack, I've also got a prototype Lithium Iron Phosphate battery that is made up of cylindrical cells in triangular arrangement similar in layout to the triangular 36V NiCad and NiMH packs we've been getting made for the past couple years. It also fits nicely inside the triangular frame bags from Mountain Equipment Co-op. This unit is nominally 36V 10Ah (made up of 24 'F' type LiFePO4 cells in a 12S-2P arrangement) and it has a proper cell balancing BMS. So far it is working great on the discharge side, but it doesn't handle regen currents very well, so it is always run in parallel with the LiPoly packs that do.

You go boy! You are going to be my hero! this is just awesome. Be careful, keep us posted, and godspeed! I plan to show my middle school kids this blog and show them that mommy's Land Rover at carpool is not the only way to get home from school.

A big part of this trip is to field test a number of components in a seriously demanding manner, and the regen motor controller is chief among them. This unit is quite a few years in the making, I think I'm at PCB revision number 12 or 13 now.



There are a few things this controller does which have been IMO long overdue in the ebike scene:
1) Programmable limits : All of the controller parameters such as maximum battery current, maximum motor current, low voltage cutoff, max regen voltage etc. can be set to whatever value you like within the limits of the controller. With this 6 mosfet version, the battery current limit can be set from 0 - 30 amps, the motor current limit can be set from 0 - 45 amps.
2) Completely Waterproof: The entire controller is potted in epoxy so there is simply no possibility even of water damage. It can be run entirely submersed, in fact the controller would like that for the great heatsinking.
3) Small Size: This thing is about 1/10th the size of the Crystalyte 35A motor controllers so it can actually mount discretely on the bicycle.
4) Proportional Regen: When the regen switch is activated, then the throttle controls the intensity of the regen braking. The regenerative braking is motor current (hence torque) regulated, and you can set the maximum regen motor current in software.
5) Pulse by Pulse Current Limiting: You can short the output motor leads and run the controller full throttle and not blow a mosfet. Nice feature to have when the axle spins out and severs all the motor leads.
6) Current Throttle: The throttle input directly controls the battery current and hence the vehicle power. If you have the battery current limit programmed to say 20A, and ride half throttle, the controller will deliver 10A of power regardless of your speed.
7) Sensored and Sensorless: If there is a hall cable connected it will run as a sensored motor controller, if there are no hall signals present it operates sensorlessly. If the hall senor was initially connected, and then fails in the middle of your ride, the controller will detect this and switch over to sensorless mode without loosing a beat. I don't really need to say much more for people to know what this means for reliability!
8.) Overtemperature Protection: Rather than shutting down when the controller gets hot and leave you stranded on a hill, the controller automatically scales back the motor current limit value as the heatsink warms up, so it will protect itself from getting too hot while at the same time never cutting out completely.

There are a few more things too, but I think that sums up the important ones.

Wow! I'm speechless! But does it clean the house too! Congrats are in order. It looks like one step closer to perfection in controllers!
otherDoc

That controller is full of win. Excellent work. When can we get some 72V versions?

Link wrote:That controller is full of win. Excellent work. When can we get some 72V versions?

Heh, we'll right now I've got the 100V 4110 mosfets in there but am stuck with a 63V capacitor! So I can't do any 72V testing for the time being, but yeah, that is obviously on the agenda!

Justin

Another item we've been working on for a while here are high efficiency bike lights that run off the main battery pack. These 6-LED rear LED lights have a DC-DC converter input stage and will work with anywhere from a 12v to a 100V battery pack, drawing about 1/3rd watt yet still visible from miles away. They're also entirely epoxy encapsulated, you can run them under water, drive over them with a truck, even smack with a hammer and they'll keep on glowing.



For the front lighting system, there is a 12-LED 1 watt white light that is similar to the rear lights above. This current consumption of this is low enough that it is easily run from the power going to the CycleAnalyst, so there is no need to bring additional wiring up to the handlebar, I simply drilled a hole into the CA enclosure and tapped into the power going to that.



However, for going fast the 1 watts of LED doesn't light up the road far enough in advance, so there is also a 10 watt HID light on the bar as well. This is powered from a DC-DC buck converter (not shown) that also runs off the main battery pack.

Awwwsome !! I'll have cold beer waiting for you in the fridge !!

That controller = Daaaaaaaaaaym !!!

4) Proportional Regen: When the regen switch is activated, then the throttle controls the intensity of the regen braking. The regenerative braking is motor current (hence torque) regulated, and you can set the maximum regen motor current in software.

Cool idea!

Nice. That controller is pure eBike p()rn!
Good luck with the ride!

Justin, this is awesome.

Especially the controller. Those features are sorely needed. Let us know when you want beta testers

But out of curiosity, why a Golden motor, rather than, oh, say Crystalyte?

Also, the semi-recumbent setup is interesting. Have you considered just getting a Day 6 and attaching an Xtracycle? Or maybe that would detract from the aesthetic.

Good luck on the journey!

Morgan
http://cycle9.com