CroBorg Super Commuter

I use conductive grease on my XT90's and they do come apart more easily than not using it. By the way, Astroflight originally designed the XT 60-90 series. I wonder how they got to China? Licensing? Prolly not.
otherDoc
 
The XT90's come apart pretty easily, a little grease should help.

I ordered some of that superconducting (*) 14 gauge wire from BuddyRC in case I decide to try this. Still not certain I'm going to do it, but might want to and should have the materials in hand just in case.

Here's the challenge. We have four XT90's on the batteries to parallel. In this case 4 #14 wires from the XT90's. Paralleling two #14's is equivalent to 3 gauges larger, or 11 gauge, so doing it again for four brings us to 8 gauge equivalent. So four #14 wires is just right for an 8 gauge equivalent parallel output.

These four 14 gauge wires need to be brought together somehow to keep good balance, and allow charging at each 6S bank. So I could use a sleeve, or I could just use a PP75 to bring them together, it has a built-in crimping sleeve that will take up to #6. I already use PP75's to deliver power to the controller. So two of the four locations are already PP75's. The other two locations are in between the banks of batteries. They are spread out, and there is room for them. With this approach ALL the sleeved joints go away. Those are very stiff and fairly bulky.

There are many ways to do it. But combining four #14's into one XT90 would be difficult. Crimping four #14's into one PP75 is easy. And the lengths can be specifically tailored for each connector's location which will reduce extra wire bulk a lot.

(*) Not really superconducting wire, it is just good fine stranded Silicone insulated wire, with a very optimistic rating. :)
 
I love the travelogue, especially at 4am? lol. In fact, the description of the load on the bike on that stretch is very helpful for those who ride that stretch. Going from 0 to 25 on that grade is really impressive with 6kw. Is the Sabvoton set to not exceed 6kw or can the controller and motor take more for peaks? How fast does to Borg go on the flats at 6kw?
 
The Sabvoton Sinewave Controller is very programmable. Much more so than the Infineon. There is an app, but the interconnect is USB/serial. It is always "live" so it can be read out and programmed while riding, if you had that set up.

It can definitely take more than I'm putting through it. Looks like I'm using about 50% of it. After blowing up a few 24 FET controllers, I'm taking a conservative approach, and these settings are performing well for commuting. Probably would change them for racing, if I did that.

Some Sabvoton Specs I collected from my notes:

24 IRFB4110 FET Sinewave controller, uses hall sensors and FOC
6KW continuous, 12KW peak for 3 min
150A max, 85A continuous battery
phase current 150A rated, 350A max (450A protected)
0-75A slide recharge
hall sensor learning
field weakening 0-100A
phase current control throttle, adjustable ramping w separate up and down rates
bluetooth and usb interfaces
zombiess's units have variable voltage input for regen/ebrake

zombiess recommends 150A battery, 300A phase. (Cromotor@18S)

I'm running 80A battery 120A phase. I don't need the front wheel lifting off the ground. At 80/120A it accelerates smartly and the front suspension unloads a lot. If I pedal hard while under full acceleration I can feel the front wheel bouncing off the ground, so it is not far from lifting. :)

At my settings, even after climbing the hill the Sabvoton is barely warm. The CroMotor warms up a bit more than the controller. But it is only warm.

I have field weakening set to zero. That would raise top speed and allow using more power, but I have not investigated that. It might be useful for a motorcycle, but this is a bicycle... Using FW would also decrease range. I'm generally interested in maximizing range.

On the level I can't run 6KW continuous. That power level only occurs on hard acceleration and steep climbing, even at 15% gradient as the speed ramps up the power drops off due to back EMF. I think it drops down to 3KW or so, hard to look at displays while navigating the potholes and traffic.

Top speed is 32-33 with 18S and 17" Moped rims and Michelin Gazelle 3.0 rear tire. On level ground it is around 1KW. It is hard to tell, I haven't tried to characterize it that carefully. Speed is more than enough for commuting. Torque throttle makes it easy to control.

I would say the only downside to the Sabvoton is the size and weight. It is a bit much for most bicycles. I had to reorganize the battery pack out of the lower Borg battery section because this controller would not fit in the upper rear controller area of the frame. The Adaptto is much smaller, but this has some downsides as well. The Adaptto may be easier to blow up, I've heard. The Sabvoton seems to be very tough. The Adaptto's seem to do quite well, so they are not fragile either. I'll probably try an Adaptto some time too, especially on a bike with less room for a large controller.
 
Alan B said:
I would say the only downside to the Sabvoton is the size and weight. It is a bit much for most bicycles. I had to reorganize the battery pack out of the lower Borg battery section because this controller would not fit in the upper rear controller area of the frame. The Adaptto is much smaller, but this has some downsides as well. The Adaptto may be easier to blow up, I've heard. The Sabvoton seems to be very tough. The Adaptto's seem to do quite well, so they are not fragile either. I'll probably try an Adaptto some time too, especially on a bike with less room for a large controller.


Maybe, but people with Adaptto are running 140A/150A battery and 350/400A phase.
 
Maybe, but people with Adaptto are running 140A/150A battery and 350/400A phase.

Pretty similar to Sabvoton's full ratings of 150A Battery, 350/450A phase maximums.

I haven't seen any Sabvoton's blown up, have seen a few Adaptto's. But this is not very statistical, numbers are very small. Not enough to assign certainty. The Adaptto has a lot more features packed into a small footprint, less mass and less thermal dissipation.

I'll probably use the Adaptto on a mountain bike where there is much less controller space.
 
Yes, not everyone runs as conservatively as I do. Zombiess for one pushed the Sabvoton hard enough to get it quite warm. Given the significant thermal mass and large heatsink the Sabvoton has, that same treatment would probably have overheated the physically much smaller Adaptto which would cause it to reduce power and protect itself. I would compare it to a big block vs small block engine. The small block can put out pretty much the same power but not as easily or for as long. They are both good controllers, and they are using the same FETs so their capability should be very similar. Then there are the issues of the quality of the FET drive setup, the power handling layout, the thermal path, mass and dissipation. Some of these we can easily see, some are buried inside or hidden in the circuitry and so harder to compare.

If I was going to run a controller really hard, I would choose a big heavy one with excellent gate drivers, well designed current path, and a big heatsink rather than something small with limited dissipation and thermal mass.
 
Today I made my first round trip commute without charging. Not that I plan to do that, but after last week's final commute I intenionally didn't charge the Borg, and since the weather was going to be wet on Tuesday I didn't charge it on Monday either. Tuesday morning the weather report had cleared (no rain), so I decided to ride and test out the operation of the battery deeper in the capacity pool. Here's the charging results after a complete round trip commute:

20150324_122307.jpg


You can see it took about 20 amp hours, which previously would have exhausted the battery, but now is only a 2/3 drain.

The voltage did sag to 66V (which is the nominal value) right about 50% of capacity (amp-hours). At 20 amp hours it was 65-67 volts depending on the load.
 
I really wish you could do 2P of the 16AH multistars. They would have yielded better performance. Ive been running 1P and seeing the performance you are seeing but 2P was very stiff to me.
 
icecube57 said:
I really wish you could do 2P of the 16AH multistars. They would have yielded better performance. Ive been running 1P and seeing the performance you are seeing but 2P was very stiff to me.

I don't think they fit into the space well. Do you really think that 2P of 16AH is much different than 4P of 8AH?
 
ahh I see not very different except the amount of connections. What is your max draw. It seems like you maybe at a higher Amperage than I am so Im not seeing the sag as much.
 
icecube57 said:
ahh I see not very different except the amount of connections. What is your max draw. It seems like you maybe at a higher Amperage than I am so Im not seeing the sag as much.

Max 80 amp battery setting. That voltage range includes load as well as regen, so is larger than what you might see with only load. Load is CroMotor fed with the 24 FET Sabvoton. The load is a steep hill, the regen is also a steep hill. Battery was 2/3 discharged and fairly cool in the morning.
 
We've had wonderful weather lately for ebiking. Today it reached into the low 80's in spots, though it was cool this morning. I snugged up the wheel nuts (with NordLock washers) and the curb side nut had loosened just a little - about one "notch". The street side was still locked up. That is with strong variable regen. I need to keep an eye on it, but it is doing well.

I checked battery balance earlier this week. Within one count on the 10mV LSDigit. Excellent!

My BMSBattery charger is taking a long time, it is set for about 2 amps and four hours is about what it takes to finish up, which means if I start it when I arrive home it won't be done till about 10PM, or even later.

Tomorrow I'm going to check out the dark side. :)
 
Today I test rode a Zero FX and DS. For full details, see the separate "Tempted by a Zero FX" thread:

http://www.endless-sphere.com/forums/viewtopic.php?f=10&t=68060

The only thing I'll say here is that the CroBorg is NOT an EMotorcycle. Not even close. Those EMotorcycles are something quite different. The CroBorg suddenly feels very lightweight and nimble, and somewhat slow. The Zeroes were still pulling hard at 70 mph! :)
 
I just dropped to 18s. It feels much better than 24s as far as speed and stability and sustained speed and motor temps. Im running 18s 2p of the 16Ah so 66v 32AH. It feels right... 27lbs of battery in the additive frame bag. It just feels right.
 
icecube57 said:
I just dropped to 18s. It feels much better than 24s as far as speed and stability and sustained speed and motor temps. Im running 18s 2p of the 16Ah so 66v 32AH. It feels right... 27lbs of battery in the additive frame bag. It just feels right.

Excellent. It feels great on the Borg too. Best improvement I've made since the Sabvoton. 2kWh is a great spot for an ebike.
 
Alan B said:
Today I test rode a Zero FX and DS. For full details, see the separate "Tempted by a Zero FX" thread:

http://www.endless-sphere.com/forums/viewtopic.php?f=10&t=68060

The only thing I'll say here is that the CroBorg is NOT an EMotorcycle. Not even close. Those EMotorcycles are something quite different. The CroBorg suddenly feels very lightweight and nimble, and somewhat slow. The Zeroes were still pulling hard at 70 mph! :)
Are any around who thought any different? :eek:
 
Alan B said:
We've had wonderful weather lately for ebiking. Today it reached into the low 80's in spots, though it was cool this morning.

Where do you live? Norther CA right? It's still in the 30's here in DC. Not quite good e-biking weather yet. It's nice here for a few weeks and then it's humid. Oh well...
I've been slowly working on my cro-Borg. One problem I am stuck on is that the cranks rub against the lower battery cover area. Did you have a clearance problem with the pedals? I think I may need some offset cranks. Other than that I'm almost ready to start commuting. Hoping I won't need to charge at work anymore!
 
Cresh said:
Alan B said:
We've had wonderful weather lately for ebiking. Today it reached into the low 80's in spots, though it was cool this morning.

Where do you live? Norther CA right? It's still in the 30's here in DC. Not quite good e-biking weather yet. It's nice here for a few weeks and then it's humid. Oh well...
I've been slowly working on my cro-Borg. One problem I am stuck on is that the cranks rub against the lower battery cover area. Did you have a clearance problem with the pedals? I think I may need some offset cranks. Other than that I'm almost ready to start commuting. Hoping I won't need to charge at work anymore!

Yes, San Francisco Bay Area, not in SF though, I'm in the East Bay, north of Berkeley. Sorry about your weather, we have it pretty good in that department. We do have a drought problem however, the lakes here look bad, we may have to quit showering and brushing our teeth soon. I gave up watering the yard and washing the cars years ago.

I have the ATS Schlumpf two speed crank with 36 tooth chainring and short crank arms to help with ground clearance and spinning faster. The chain just touches the cover, but doesn't seem to drag on it. I didn't have that cover mounted until a few weeks ago when I rewired for the MultiStars. Anyway the Schlumpf cranks seem to clear just fine.

Just above the middle of the first page of this thread there's a configuration list that I keep fairly up to date with what is on the CroBorg.

I don't have to charge at work anymore, however I have a 12A charger there and only a 2A charger at home, so if I don't charge at work it would take about 12 hours at home to put back 20 amp hours that the round trip takes, and I don't like to charge while sleeping. Of course I have parts for another 10A charger but haven't put it together yet. I have a good place at work to charge, so that's nice now, but it will change soon enough.
 
I've been working on the list of components in the Borg, improving and adding detail. Looks like the chainring I ordered is 36T, it is as large as will fit, it almost doesn't fit the covers. I think the chain is touching slightly, not much though.

This posting is about halfway down the first page of this thread for easy reference, here's a link to it directly.

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=34929&p=509398#p509398
 
20150329_184837.jpg


This little project is more work than expected.

I had to repair the switch wiring, it was twisted and torn; remove the cable end retainer link, file a flat for the magnet, find the south pole, cement the magnet on, drill out the cable adjuster to fit the linear output cable, and fabricate a perf board to fit in the small space. Then construct the circuit on the board, wire it up, and cement it into the handle. This is really starting to take shape.

There are just two components on the board - the magnetic sensor and a bypass capacitor across the power leads.

This lever will have two cables; one for the brake switch contact, and the other for the linear output.
 
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