Qulbix Q76R Frame Kits & Complete Bikes PRE-ORDER

here's a crappy video of my build which is mostly done now
[youtube]oHXEQKNUoQI[/youtube]

@Offroader : yeah grey is pretty nice ! Quick question : are you planning on welding or soldering the connection between each cell ? I'm not that into making my own battery but my understanding was that spot welding was recommended as there's a risk of shorting the cells when soldering (if the solder flows to the negative)
 
TheBMallory said:
here's a crappy video of my build which is mostly done now
Click to expand...


Looks nice. I liked how the illuminated lightning bolt turned out. Nice work.
 
280 cells, damn. I guess I won't have any problems with 22s10p then.

I think I will actually use your pictures to plan the cell layout, very helpful, thanks.

My Q76R is almost here. Then the build will commence!
 
TheBMallory said:
@Offroader : yeah grey is pretty nice ! Quick question : are you planning on welding or soldering the connection between each cell ? I'm not that into making my own battery but my understanding was that spot welding was recommended as there's a risk of shorting the cells when soldering (if the solder flows to the negative)
Click to expand...

I am actually going to both spot weld and solder. I would not solder direct to the cells as you will probably damage them. You will have to buy a spot welder to build your pack. I bought one from the forum that works with a 12 volt car battery.

What I plan to do is solder wire to the center of a nickel strip, and then weld the nickel strip to the battery. I'll show pictures when I get to that step. This is the best way to pass the current as you need 1/4 less copper than nickel.



jmz said:
280 cells, damn. I guess I won't have any problems with 22s10p then.

I think I will actually use your pictures to plan the cell layout, very helpful, thanks.

My Q76R is almost here. Then the build will commence!
Click to expand...

Yes the layout does help to see exactly what will fit and mark which cells will be used. I recommend unless you are going to max the battery pack at 281 cells, I would avoid using the cells in the top left as they fit a little close to the frame and unless you build the pack perfectly tight they may cause problems. In the picture I would design the pack to avoid using those cells in the top left marked in yellow X. Without them you will have enough room around the rest of the pack for clearance.

I'm going to use them and the pack should fit, but I believe I may have to file a tiny bit of frame, like 1 mm, where those cells hit because my pack ins't perfectly tight. I might be able to also insert the pack on a slight angle and not have to do this. I'll have to see when I have the pack completely glued which is taking a long time.


 
I finally glued the pack. It took a very long time. Probably like a full day to get it done. There is a small learning curve with this, so you do get faster.

What made it take longer is I put an extra layer of kapton tape where the cells in series touch other cells. I think this was probably a waste of time to be honest. I saw someone do it with one of their pack builds so I figured maybe it is worth it, but I question what will an extra layer of kapton tape really do if the hot glue fails and the cells are able to move around.

One tip I can give you is don't buy the cheapest Glue gun. You need to lay the glue on thick and fast before it dries, spend an extra $5 or $10 on a better one.

The pack weighs 30 LBS or 13.6 KG. I'm wondering if maybe I went too big with this pack and having second thoughts about if I need all that capacity. My old pack of 2.3 KW was not sufficient all the time so I wanted a larger pack. I want to start taking the bike into Manhattan and have enough battery power to do a lot of riding there before returning home and 2.3 KW was just not enough.

3.5KW seems to be so much. The only problem is the added weight of such a large pack, however this 3.5KW pack is still 6 lbs lighter than my 2.3KW lipo pack, which weighs 36 lbs or 16.3 KG.

Another thing that bothers me is after gluing the pack it got a bit larger (I knew I should have glued it together in the frame opening), and now doesn't fit in the frame opening. It will require me to file so slightly the frame opening for it to fit. I just hate the thought of filing down a brand new frame. You won't see the where I had to file it because the side covers will cover up the area. I don't think it will weaken the frame any because I only need to file a very small amount.




 
Nice work, just as I said, one will always think that gluing will take 30-60minutes but in the real world it takes one day for such a pack.
Now it is cutting the strip, welding and then soldering and then soldering balance leads, soldering the main leads and then package everything :) I would say another 3 days or a week if you have a day time job.
 
For those interested, I decided to order the charge plug that fits the charge port.

Since the one that comes with the bike is 2 pole connector and rated for 20 amps continuous charging, I decided to just buy the 4 pole version rated at 40 amps and also the 4 pole charge plug. I will just solder the charge wire to two prongs for positive and two prongs for negative.

http://www.neutrik.com/en/speakon/speakon-chassis-connectors/nl4mp-uc

http://www.neutrik.com/en/speakon/spx-series/nl4fx
 
Allex said:
hah I wonder why everybody started to go with speakons, two years ago no one would look at those 8)
Click to expand...


Is there anything wrong with those? I never used a charge port, but to be honest I'd rather have a simple one plug connector rather than deal with bullet connectors.

The Qulbix kit comes with this charge port, but doesn't have the plug.
 
Allex said:
Nah nothing wrong but I did notice the popularity gain after my initial instalment along with my adaptto gear.
Click to expand...

right you are!
before i used the 2-pole 16A powercon and thought thats the "best" available.. :D
 
Allex said:
Nah nothing wrong but I did notice the popularity gain after my initial instalment along with my adaptto gear.
Click to expand...

thx alex :)

Offroader said:
For those interested, I decided to order the charge plug that fits the charge port.

Since the one that comes with the bike is 2 pole connector and rated for 20 amps continuous charging, I decided to just buy the 4 pole version rated at 40 amps and also the 4 pole charge plug. I will just solder the charge wire to two prongs for positive and two prongs for negative.

http://www.neutrik.com/en/speakon/speakon-chassis-connectors/nl4mp-uc

http://www.neutrik.com/en/speakon/spx-series/nl4fx
Click to expand...

i use 2 pole, they are good for up to 40a, tested. pm me if you need a pair.
 
I decided to completely dismantle my hot glued pack. I wasn't happy that I couldn't fit it inside the battery compartment without filing it and decided I didn't want to do that.

I made a lot of mistakes when hot gluing the pack and made it too large. The problem was it was my first time doing this and I had to make sure every cell was perfectly tight.

With a good tip from a forum member I was able to use a little isopropyl alcohol and that loosened the hot glue bond and I had the pack dismantled in an hour.


By chance I found a better cell layout that gives a tiny amount more room evenly around the pack and still fits 280 cells.

I also ordered a much better hot glue gun and I am considering hot gluing the pack inside the battery compartment opening to make sure it stays perfectly tight.

 
Ah, what in pain in the backside. Hope the new layout glues up well for you. Little for error given max battery approach. Wish you the best of luck for take 2 :lol:
 
offroader said:
I also ordered a much better hot glue gun and I am considering hot gluing the pack inside the battery compartment opening to make sure it stays perfectly tight.
Click to expand...

Smart. If you can glue the pack inside the frame no need to grind down frame. Care to do a timelapse or a video when gluing the batteries?
 
The connector that comes with the Q76R is a Neutrik type right?

I have some 4-pole CN Linko connectors that seem really solid, and they fit in the exact same hole layout.

http://www.cnlinko.com/product_show.php?id=1181&pid=475

http://www.cnlinko.com/pdf/YM-20.pdf
 
Just an update, words can't describe how difficult building this pack is. I don't recommend anyone to build a 280 cell pack as it increases the difficulty exponentially.

The tolerances when gluing the pack need to be perfect to fit inside the frame so you don't have any choice but to glue with the pack compressed together which adds to the difficulty.

If I only could reduce cell size by 3 it would have helped a lot.

Problem is I wanted 20s, and because of that I could only have 20s12p or 20s14p, there is no way to distribute the load evenly through the cells with 13p. I probably should have considered 19s14p to be honest.

Because the pack isn't square I need to then solder wires between all series connections.

I did finally glue the pack together and I can fit it inside the frame, but just barely.

I will now need to custom mill plastic battery holder along the bottom of the frame to make it flush with the frame opening. Battery needs to slide in and out without falling down into the frame because I won't be able to get it out easily.

My recommendation is if you are going to build such a large pack to build it in multiple pieces instead of one large pack.
 
Quokka said:
Offroader, how do you think your original 20s 12p would fit?
Click to expand...

20s12p no problem. Honestly anything with about 274 and lower will fit easily but probably best to build pack compressed.

260 cells and lower dont need to compress pack as there will be plenty of room.

But 20s12p would fit easily. How do you intend to build such a pack? I have drawn a 20s12p pack design using copper wires soldered to nickel strip.
 
offroader said:
Problem is I wanted 20s, and because of that I could only have 20s12p or 20s14p, there is no way to distribute the load evenly through the cells with 13p. I probably should have considered 19s14p to be honest.
Click to expand...


Can you elaborate on that? I do not follow what you mean.
 
i believe he means the placement of the cells is so complex that it would be hard to keep the resistance of the connection form one p-group to the next similar (so that every single cells sees the same current).

offroader, i can imagine that it takes a lot of time to build that pack.
now, do you still have the space for insulation between the s-groups for better protection against a short?
i normally use some tape with about 0.2mm thickness for having a larger gap here. with the shrinktube only there is almost no distance here.
 
Planning my battery layout thanks to Offroaders useful pictures. 22s9p should be a cinch.

By using regular 3x3 parallelogram sections, this should give very closely balanced impedances for each cell with a two-layer grid of 0.3mm nickel. I also have some beautiful 0.15mm copper sheet that I might be able to use for some of the irregular connections, though I will have to test if my spot welder is capable of making a dent in it.

The only question would be whether it would be better to have the cross-group interconnects (red) as the top layer or the bottom layer. Using the bottom layer should give a lower resistance, as the main current only has to pass through one nickel-nickel junction. In theory, at least when making straight-line interconnections between groups of cells, the total impedance from both the top and bottom interconnects will be the same, and only negligible current will flow in the 'balancing' layer (blue).

https://imgur.com/Wj4rNtF
 
jmz said:
Planning my battery layout thanks to Offroaders useful pictures. 22s9p should be a cinch.
Click to expand...

wouldn't it be possible to place 22 of 9p groups side by side into that frame (from left to right)?
doing so, THAN would make welding and gluing the pack a cinch, because you could use one single 25mm nickel strip for making p and s connection at once :wink:

you only would need to beef up the nickel where you solder the main leads, like this:

qpjsqO.jpg


By using regular 3x3 parallelogram sections, this should give very closely balanced impedances for each cell with a two-layer grid of 0.3mm nickel.
Click to expand...

with this design, the resistance only would be similar between the groups from left to right.
the connection from the bottom up would be not (group at the corner to the one overlying or below).
 
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