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Posted on 3 April 2013 at 10:19 pm (CET)
Category: Batteries, Parts
Posted on 3 April 2013 at 10:19 pm (CET)
Category: Batteries, Parts

Today I received the BMS (Battery Management System). Had to get this all the way from America since we don't have anything like this here. Or well, only 3-4x more expensive. Pretty quick delivery, bit less than 2 weeks. Also didn't have to pay much tax for import, way less than expected.
The BMS is there to take care of the batteries so you can't under- or overcharge (very important for lithium batteries). The batteries also get balanced while charging so that you can get the maximum capacity out of them for a bit higher range.

Here you can see the whole system. All the small printboards will come on each of the batteries and are connected in series. I ordered a few extra just in case I'd destroy one making a wrong connection.

E-Streetquad Some more important parts, the BMS


On bottom left is the head-end board as they call it. The whole loop of battery boards will be connected to this and this one basically manages everything.
In the middle is a sensor that can measure the current, voltage, temperature and some more things. It sends all this information to the display you can see on top right. On this display you can also see the capacity of the batteries.

E-Streetquad Some more important parts, the BMS


Head-end board coincidentally fits in the small box that I got with the charger. This was actually meant for the little relais but I can place this in there as well now.

E-Streetquad Some more important parts, the BMS


Last week I still got some more parts, will post them here as well since it's all part of the project.

E-Streetquad Some more important parts, the BMS


Black cable glands in trade for the wrong gray ones. Rubber insulator caps for the terminals of the controller and motor. Some more cable shoes with different sizes (will still have to order more of the big M6 ones since the batteries also need M6 instead of M10). Orange heat shrink only for color coding on the black cables I received for the charger and DC-DC converter since this is also high voltage.
Then there's still a small charger that can charge one 3.2V lithium battery at a time. I will need this to charge all of the batteries for the first time to get them balanced. The batteries will all be connected in parallel for this. After that the BMS will keep them balanced. Came all the way from Czech Republic, just can't get these things here. This won't be fitted to the quad bike but it does make sure the batteries are immediately ready for use.
Also 2 steel blocks. I will have these routed together with the motor mount so they'll get a bit smaller, sloped and lighter. After that I can get them welded on the rear swing arm and the motor mount will be attached to these blocks.

The plate for the motor mount is also ordered already. It was pretty hard to find the correct size. I again couldn't find it here so I ordered it in Germany.

Posted on 25 March 2013 at 12:49 am (CET)
Posted on 25 March 2013 at 12:49 am (CET)

A while ago a friend of mine came by, he is in the metalworking business. Together we went looking for the best solution to mount the motor and if he could make a mount for it. He already had a few ideas but he would go and make a drawing of it first. Ended up being a few drawings since a few modifications had to be made.

Meanwhile I received the final drawing and I'm checking if it can actually be fitted this way. First off, here's the drawing.

E-Streetquad Trying to find the best way to mount the motor


E-Streetquad Trying to find the best way to mount the motor


The 2 blocks that you can see will be welded on the rear swingarm.

Here you can see where the motor will be placed. As you can see there is no need for modifications with the suspension, it fits perfectly in there.

E-Streetquad Trying to find the best way to mount the motor


And I again made a paper model to see if the motor mount would fit. Still think it's the best way to measure.

E-Streetquad Trying to find the best way to mount the motor


Only on the bottom left it will get a bit more sloped and only 2 mounting holes for mounting on the swingarm since the frame on the left side of the motor is in the way.

E-Streetquad Trying to find the best way to mount the motor


The motor mount can be made now. Will have to get the materials myself first, after that it would probably take around 2 weeks to make it. It'll probably become the best looking part on the quad bike.

Posted on 9 March 2013 at 10:06 pm (CET)
Posted on 9 March 2013 at 10:06 pm (CET)

Today I made a test setup to check if the controller and motor work well. First I setup the controller on my computer, very easy to do and can't really set anything wrong because of the clear descriptions. I then cut some cables out of the old wire harness, didn't really have anything else to use. To be sure I also added the keyswitch so I could turn it on and off.

E-Streetquad Controller and motor test


Thankfully everything worked perfectly. Also made a short video so you can see the motor spinning. When turning on the controller you always have to wait before you can control the motor because the capacitors are being charged up. If this wouldn't happen and they directly get high voltage it could damage them. After this is done the contactors (big relais) close, the motor can be controlled and you can 'drive'.


Sorry it's so short, had a bit more footage but something went wrong with filming. By the way, this is with 2 12V batteries in series, so 24V. But in the controller I set a limit for the motor of 13V 10A. Did this because I wasn't sure the small Chinese wires I used would survive with higher voltage and current. But I must say I'm impressed, it was already pretty hard to keep the motor in place with 1 hand when I fully opened the hall sensor, already noticed the torque quite well. I did see 16V going to the motor and 18A so the limit isn't working perfectly. So this was 288W (0,288kW). Still hard to imagine how it'll be like with 25+kW but it's looking good.

Posted on 8 March 2013 at 12:14 am (CET)
Category: Electric motor, General
Posted on 8 March 2013 at 12:14 am (CET)
Category: Electric motor, General

Tonight I detached the rear swing arm partially and fitted the motor. I knew that it would be a close fit but it really only has a few millimeters to spare.
Seen from the side it all fits well, some space left even.

E-Streetquad Fitting the motor


Seen from the rear, not a lot of space but I think it's enough to still be able to mount the sprocket on there. The sprocket will stick out of the axle just a bit to get the chain aligned with the rear sprocket.

E-Streetquad Fitting the motor


But then on the other side, I think it's 2-3 mm of space there. It's just barely enough as long as there won't be any play in the swingarm.

E-Streetquad Fitting the motor


I'm happy that it fits just like I planned. Now I have to get some mounts made.

I also still received the new banjo bolt with sensor for the brake lights. So I replaced this one as well.

E-Streetquad Fitting the motor

Posted on 6 March 2013 at 10:07 pm (CET)
Category: Electric motor, Parts
Posted on 6 March 2013 at 10:07 pm (CET)
Category: Electric motor, Parts

Today I got a package with a total weight of 18kg, what could it be?

E-Streetquad Motor has finally arrived


Finally received the motor from LMC Ltd., with some more important parts.
Here's the motor, think it's pretty cool how you can get so much power out of such a small motor. But it's pretty heavy for the size, it weighs 11kg.

E-Streetquad Motor has finally arrived


And the other parts.

E-Streetquad Motor has finally arrived


On the left 2 contactors (big relais) to switch positive and negative to the motor, so to be able to drive in reverse. Much bigger than I expected, will have to see where I could best place this.
On top the emergency switch with lock, with a press of the button the 72V towards the controller can be disabled with this. Just in case I can't turn off the controller with 12V (keyswitch/killswitch) if anything goes wrong. Or for safe maintenance. The key is needed to turn it on again.
At the bottom another contactor, this was intended for a different controller at first. The controller I have now already has 2 built in. But to be sure I still kept it in my order. Planning to use this in the middle of the battery pack now so it's a bit safer to work with (36V DC is a lot safer than 72V).
On the right the main fuse with fuse holder. Yet again a problem though, it doesn't fit. The bolts are just a bit too thick, the fuse doesn't fit on it. Comes all the way from England so it'll be hard to send back to get a new one. Will have to see how I'm going to solve this, otherwise I'll just buy a different fuse holder here.

First thing I'll do now is remove the rear swingarm to find out the best way to mount the motor on there (can't get it in without removing since the motor is just a bit too big to fit through the frame). I can only mount the motor on one side so it'll have to be pretty sturdy.
After that I'll have some mounts made for the motor and controller and I can finally start adding things onto the frame and connect all cables. At least up to the batteries since I won't have them yet for another 7 weeks or so.