Tostino's Ebike Rev-3 Recumbent

[dnmun]

nope, heating is I^2 X R = Watts. always better to get your power at higher volts, because it takes less amps.

 

[tostino]

nope, heating is I^2 X R = Watts. always better to get your power at higher volts, because it takes less amps.

I know that is true for heating through wires, I was just wondering if it carried over for FET's. I know that you may not get as many watts at a lower voltage through the same FET's, just possibly a few more amps at the lower voltage than at a higher voltage closer to the FET's limit.

 

[torker]

Wow, Did I read that right? You have run over 40 mph. on an EZ-1 I ask because I have an EZ-1 and 25 seems fast on my toureasy. I can't imagine 40+ on the ez

 

[dnmun]

nope, heating is I^2 X R = Watts. always better to get your power at higher volts, because it takes less amps.

I know that is true for heating through wires, I was just wondering if it carried over for FET's. I know that you may not get as many watts at a lower voltage through the same FET's, just possibly a few more amps at the lower voltage than at a higher voltage closer to the FET's limit.

it is really the same thing. the mosfet has internal resistance when it is turned on and that is just like a wire. the breakdown voltage doesn't have any bearing on the current carrying capacity. the breakdown voltage is the voltage it can withstand when turned off.

that's as much as i know about it, some others here are more educated about how they work.

 

[Doctorbass]

I sadly haven't had time for a distance ride (though I did put 45 miles on the bike today).

However, today nearly ended in disaster. Let me explain.
I woke up today, and noticed my tire had heavy wear. The nylon was showing through in some spots. So I took a ride up to the bike shop to pick up a new tire. I didn't have enough time to change it before I had to go to class, so I just said to my self i'd do it when I got back.
So I make it to class, and almost all the way home, and I had to stop somewhere to do a little job for someone. I finish the job and start heading home again.
I am less than 2 miles away from home, going 40mph with cars behind, and in front of me when I hear a LOUD *BOOM* that sounded like a gunshot at first. My tire had blown out, and my back tire was tracking all over the place. I don't have all that much stopping power from 40mph with no back tire. Luckily, it is a 2 lane road with no curb, and grass to the side, so I get it off the road so I don't get splattered all over someones bumper. At this point i'm still going 35 off road, and trying not to lay it down and eat shit.

I finally manage to get it slowed down and safely stopped where I won't get killed, and see it wore through the tire and into the tube, which bursted open. At this point I call my girlfriend, who comes to pick me and the bike up in her truck .

That was a scare for the day. Don't need another one of those for a while.

Lesson learned, should have just taken the car...It's just not as fun (I guess neither is being dead though)

Tostinos, Nice to see you got a great battery pack of the Makita ! :wink:

I also had a flat on my rear tire.. but guess what.. it's a 80 PSI 2.4" wide tire and i remember i've inflated it to 75.. for "safety margin".. lol.. but i forgot to reduce pressure on hot sunny days like July.. ... Just when i was brigning my ebike to a friend that was curious to try it, suddenly I heard also a big BANG !!!.. just like a 12 caliber gunshot !!
I was on the front of a gouvernment building and few officer and guardian immediatly went out of the building, thinking they had an attack!!.. .
The worst.. I still was not thinking it was my rear tire!!!.. the sound just bounced on the building wall and i thought it was really someone with a gun !!

Then I had my friend that saw the flat and advising me about it... !.. The officer aws so surprized to see it was... my ebike...the cause!!

Doc

 

[tostino]

@torker
Yes, you did read that right. I am hitting 44.8mph hot off the charger on the flats with no wind. It isn't the most stable ride i've ever had . Just a little wobble of your arms will make it go ALL over the road, not to mention leaning. I wouldn't want anyone riding it at that speed other than me. Strangely, I feel pretty safe going that fast (after 700 miles of practice lol).

@dnmum
Thank you for the explanation, I understand.

@Doc
Yeah, the pack is GREAT! It's not the lightest battery ever, but it can sure put out the power without much sag. It's also staying perfectly balanced, which is a plus .

When your tire went out, how fast were you going? Did it feel like your back tire was tracking all over, not following your front?
That must have been quite a scare thinking it was someone shooting! And with cops all over too 0_0. Glad it didn't turn ugly.

 

[tostino]

Just went for a nice relaxing ride today. I've been sick this past week, and needed to get out of the house.

CA log-
Miles: 49.00
AH used: 20.68
WH used: 1140.0
WH/MI: 22.6
Regen: 3.2%
A-min: -37.4
A-max: 74.37
min volts: 47.8
max speed: 44.9
average speed: 23.8
trip time 2:03

The ride was through a park, and on a trail next to an interstate.

I have a video of a ride to the local mall yesterday that I need to put on my computer, and then up here.

 

[dnmun]

impressive. that is 37A regen current? i think the 74A is the highest power you have recorded so far.

now if they would just give us one lane of the freeway so everybody could ride their bikes at 44mph without stop lights.

 

[tostino]

I was actually being easy on the acceleration today. Normally it peaks at 86a. But your right, that is just a peak. After the first second or so, it settles at around 68a until it comes off current limiting.
Edit: and yes, that is the regen current. It spikes that high for the first few seconds when reneging at full speed. At 45 mph if I switch from delta to wye, and turn on the regen it spikes that high. If I leave it in delta, I regen at like 19a for the first few seconds.

 

[dnmun]

that makes sense that it would be 18A for one phase wire connected at a time, versus 37A for two phase wires.

how did you end up gluing the relays? i bet that would be a good place for the JB Weld.

 

[tostino]

that makes sense that it would be 18A for one phase wire connected at a time, versus 37A for two phase wires.

how did you end up gluing the relays? i bet that would be a good place for the JB Weld.

I glued them with Gorilla Glue. That stuff has actually held most things better than jb weld for me. I had a look inside the other day really quick, and they were still held securely in place.
I kinda wonder if the relay contacts are heating up, and how much when under hard acceleration. If I could find some beefier ones, i'd use them, but I couldn't find any that were rated for any higher than the ones I have. I don't think it'll be a point of failure, however, if it is heating a lot, replacing them would give me slightly more usable power by lowering the resistance.

Edit: Charging battery complete. It took 7:05. 41414mah put back into batteries. Charge rate at 6.05a.
I put my packs in parallel to charge, and series to run.

 

[tostino]

I have videos!

One is from a couple days ago, I went to the mall: http://jeeeep.com/Bike/Mall_ride.avi

The other is from this morning on a bike trail at a local park: http://jeeeep.com/Bike/Trails.avi

The video from today, I averaged 38mph, and 39wh/mi.

 

[lifepo4ever]

nice job tostitos !! I will keep this for the video

 

[tostino]

Well I had a crappy day today, my motor isn't working. I opened it up, and one of the phase wires had chafed through the insulation and shorted to the motor case.

I was just going to a friends house to drop something off, and within a couple miles, the motor started making strange sounds. I pulled over and checked that my halls were all making a good connection, and that didn't help, so I turned around and pedaled home.

When I got home, I opened up my case, and I see the phase wire that shorted to where the wires come out of the shaft (on the inside). It had blown a little of the metal away on the shaft from sparking.

I pulled the shorted wire out, and replaced it with a good one (not easy with 12g wires!). Tested it, and the motor still wouldn't spin. I didn't like my original wiring job between the relays, so I decided i'd replace it all with 10g wire, just to make sure it didn't short anywhere else (HUGE pain in the ass). After I put the motor all back together and tested again, it STILL didn't work.

And just now it dawned on me... "Check the halls". Of course, none of them are putting out any voltage no matter how I spin the motor. Duh! That shorted phase blew them because the motor case is connected to their ground.
The series circuit goes:
battery positive > switch on handle bars > full pack voltage to motor case (+ rest of bike) > three relays in series (80ohm each) > 200w 10ohm resistor > hall sensor negative.

So I guess when my phase shorted, it must have had to send the power back through each of the relays, than through the resistor, and into the halls to burn them up.

I guess it's time to make another order of halls! Probably get 20 or so, just so I have plenty of extras.


P.S. I'll put up some pictures of the new wiring in the motor soon for anyone who cares.

Edit: I see where those diodes would come in handy, and why i'm going to put them in when I get new halls!

 

[nicobie]

Are you using teflon coated wire?

.

 

[tostino]

Whatever the standard car wiring is.

Actually I don't know if I mentioned it before, but I had to strip all the standard insulation off of one of the three wires, and I used heat shrink in the insulation place just where it goes down the shaft. That is the wire that shorted (if you couldn't guess).
I had to do the same thing when I replaced it, because there simply isn't enough room for anything else. However, this time, I used double heat shrink, and also put some electrical tape around where it shorted last time for extra protection.

 

[tostino]

Update:
I'm so good with all things electronic, I managed to blow my controller. Completely my fault.
See here if you feel like helping, or just want to read what I did :
http://www.endless-sphere.com/forums/viewtopic.php?f=2&t=14254

 

[tostino]

So i've got everything all back together and working again.

Controller has 12 new 4110 fets, and lowered shunt resistance to 1.8mohm (stock is roughly 3.8mohm), with software amp limit set to 55a battery and 135a phase.


View attachment 1

I also changed the CA connection points on my controller to get a more accurate reading of shunt current, and tried to hook up throttle override, but failed on that.

My motor has all new hall sensors now, and the new wiring should not allow that to happen again.
I also beefed up the wiring going between the relays to 10g instead of 14g.


On top of all that, I got ANOTHER frocking flat. I was using bike store tires, which I thought would be good quality. I was right next to a walmart, 25 miles away from home when this happened though, so I just went in and got a new tire and tube. It is so much better than my previous tires. Really thick, balloon tire.
View attachment 4
It is MUCH bigger, and increased my speed by 1-2mph, with no noticeable loss of torque.

 

[torker]

Awesome upgrades. Got a recent pic of the whole bike showing how you are carrying batts etc? Are the spokes holding up ok with all the weight bias to the back?

 

[tostino]

I just took some pictures of the bike. I went to school today, and my sisters had taken my car, so I had to take the bike even though it was raining out. roughly 26 miles round trip, and it rained both there and back. SUCKY! But the bike worked perfectly.


on the charger


Batts are all in the backpack


hmm what is that?


Front bag for carrying things.


Now I did another "upgrade" in the past few days that I didn't mention yet...

I put a system on my bike:



And the power supply for the speakers

Konions can be used for anything.

Those are OLD OLD OLD speakers from the first computer my mom bought back in 1997 that I had sitting in my closet. They sound piss poor (even when new they did) and are not very loud, but it is all I had available. I hook the speakers up to my mp3 player:




Hope that last part about having a system made you all laugh .
-Adam

 

[torker]

Actually the workbench on the lvrm/bedrm carpet caught my attention. Got to be a bachelor pad. 8) I know when I was single I used to rebuild carbeurators/ cylinder heads etc. on my dining room table. I do like the stereo too..

 

[tostino]

It's my bedroom, and I sadly still live at home. Only 19, and in college.

I'm glad my parents still put up with me , i'd be living under a bridge with my ebike otherwise!

 

[Metallover]

Sweet project!

I am wondering what amp and voltage ratings you have on the relays.. And also, can you refresh me on what all you did to mod the controller?

Is the bike still in commission? How many miles?

 

[tostino]

Sweet project!

I am wondering what amp and voltage ratings you have on the relays.. And also, can you refresh me on what all you did to mod the controller?

Is the bike still in commission? How many miles?

Hey, yes the bike is still working perfectly, and i'll go check the miles now... 1254 miles.

The relays are standard auto spdt relays, rated for 14v and 40/30amp. I beefed up all the traces on the relays to cut down on wasted heat as much as I could though, as you can see in the pictures.
The relays were roughly 80ohm each, so to get them to work with my voltage range, I had to add a 100ohm, 10w resistor in series with them. I had 200ohm at first, but found out that when I got down to 50v, the relays would no longer engage, and I could not use delta.

The controller mods I remember doing are:
Adding a crapload of copper to the mosfet traces on the back of the pcb.
Replacing the fets with 4110's.
Enabled regen.
Modded the shunt down to 1.245mohm to reduce wasted heat.

At stock shunt values, I wouldn't be able to get the power levels over 100a because of software limits, and even if I could, it would waste 38 watts of heat through the shunt. With the shunt now at 1.245mohm, at 100a I am only wasting 12.5 watts of heat.

 

[Hyena]

Good to hear the relays have held up tostino.
I'm looking to do the same with a magic pie and see waht the internal controller can take before failure. I don't think the relays you've used would clear the lower profile case though. I wouldn't have thought normal automotive relays would even clear the lid of the motor you have, but I guess there's more room in there than you realise...