My build is nearly done, after much testing and failing.
At the start of my build I was thinking of bringing 2000whrs of juice. I build a temporary pack with 1500whrs, but was already doing 70kmh - so I decided to make a sleeker package. The temporary build soon killed itself anyway. I learnt a lot from this - bringing my experiences into this build.
I'll document the pack building quite extensively, the other components were bought from methods at methtek.com. I would also like to say thank you again methods, not only for supplying me parts - but for offering kind help when I was truing my rim.
It all started with a wooden frame so I'd have some idea of how much room I'd have.
After nearly building a 19s pack, I ditched that and went for 18s. Here is the setup before silicone.
Between every layer of cells there are silicone holding them together. I tested wood glue, acrylic and bathroom silicone beforehand. Wood glue definitely had the strongest adhesion, ripping the green plastic from the cells before letting go. The silicone had good adhesion, but still possibillity for repair. Later in the project, this construction was tested to the breaking point.
All done.
I added balance connectors in the form of a datacable with a clamp-on connector. You can see it sticking out at the bottom. Wrapped it in gaffa tape for added protection and cling film, to make the fiberglass let go. Looking back on this, I would take a different route and start with polyester soaked cloth. Then laying fibreglass outside this after removing the batteries.
Finished, some fibreglass quick tips comes later.
The polyester did something weird to the gaffa tape. It reeked styrene for a long time, eventually I took this off due to other events.
Mock up of how I pictured the pack staying in the frame.
Three cargo straps hold the pack to the frame. I've already done the other siden on this picture.
I allways go to the farmacy and get some cheap syringes. They are really usefull when measuring curing liquid.
Cut a bottle in two. Use a measuring cup with water to make lines on the half bottle.
Remember to cut up fibreglass before you start. Use disposable gloves at all times. The fibreglass is irritating to the skin.
Taking pictures while fibreglassing is next to impossible, so here is the finished result. Totally for the whole pack I used around 0,5square meters of fibreglass and around 2-3dl of polystyrene. This construction method forms a strong package with light weight.
Another mock up. I shortened the cables coming from the controller, but I still have some left.
Then it happened. One cell group dead. And, it was pretty hard to get to. If you count from the right bottom - its third cell croup. This was the test for the silicone. I unsoldered the connections and tried breaking it apart, not going to happen - damn it was much stronger than expected! I ended up using pieces of a plastic ice box to wedge inbetween cells to destroy the silicone. Worked ok, but took a while. Where the red silicone is visible was one of the split points. In this picture you can also see my 'bad boy charger' and my watercooled 2x0.25w 2ohm resistors working as a ~12W discharger. They're holding up
Before this I had a accident with the datacable balancing connector. It shorted within the connector, melting much of the plastic. Luckily they worked as fuses, the crappy cables - but god damn they went out with many bangs. Scary as hell. Never use data-transmission cables as balancing cables! You can see the black areas and some gaffa-tape that has melted. This was not the reason for the dead cell tho.
This is the bike as of today. It is missing top seal of battery pack, some wire shortening and some torque arms. I'm running it on 40A now. The bike is allmost all aluminium - with steel dropout inserts in the behind. Adding more beefy torque arms will be done before turning up the current to 70A.
A closer shot, I seriously need to get this cable mess a bit more stealthy. Consumption running 45kph is about 16whr/km. It climbs hills very good. Total bike weight has been prioritized, batt pack ~9kgs. Motor ~7-10kg and bike something along 10kgs. I'm 66kgs, so all in all it's very fast as it is now. 70kph is the most I've tested it to, it does not go much faster. I'll have to take it on the bathroom scale with me one time.
Just wanted to showoff my regen button as of now. I prefer not holding something in, and so this is perfect. A pushbutton (push to hold, push to unhold) that flows better with the bike will come in the future.
As for the name of the bike, it's cheesy - but I'm Norwegian and at times beardy, so why not :lol:
At the start of my build I was thinking of bringing 2000whrs of juice. I build a temporary pack with 1500whrs, but was already doing 70kmh - so I decided to make a sleeker package. The temporary build soon killed itself anyway. I learnt a lot from this - bringing my experiences into this build.
I'll document the pack building quite extensively, the other components were bought from methods at methtek.com. I would also like to say thank you again methods, not only for supplying me parts - but for offering kind help when I was truing my rim.
It all started with a wooden frame so I'd have some idea of how much room I'd have.
After nearly building a 19s pack, I ditched that and went for 18s. Here is the setup before silicone.
Between every layer of cells there are silicone holding them together. I tested wood glue, acrylic and bathroom silicone beforehand. Wood glue definitely had the strongest adhesion, ripping the green plastic from the cells before letting go. The silicone had good adhesion, but still possibillity for repair. Later in the project, this construction was tested to the breaking point.
All done.
I added balance connectors in the form of a datacable with a clamp-on connector. You can see it sticking out at the bottom. Wrapped it in gaffa tape for added protection and cling film, to make the fiberglass let go. Looking back on this, I would take a different route and start with polyester soaked cloth. Then laying fibreglass outside this after removing the batteries.
Finished, some fibreglass quick tips comes later.
The polyester did something weird to the gaffa tape. It reeked styrene for a long time, eventually I took this off due to other events.
Mock up of how I pictured the pack staying in the frame.
Three cargo straps hold the pack to the frame. I've already done the other siden on this picture.
I allways go to the farmacy and get some cheap syringes. They are really usefull when measuring curing liquid.
Cut a bottle in two. Use a measuring cup with water to make lines on the half bottle.
Remember to cut up fibreglass before you start. Use disposable gloves at all times. The fibreglass is irritating to the skin.
Taking pictures while fibreglassing is next to impossible, so here is the finished result. Totally for the whole pack I used around 0,5square meters of fibreglass and around 2-3dl of polystyrene. This construction method forms a strong package with light weight.
Another mock up. I shortened the cables coming from the controller, but I still have some left.
Then it happened. One cell group dead. And, it was pretty hard to get to. If you count from the right bottom - its third cell croup. This was the test for the silicone. I unsoldered the connections and tried breaking it apart, not going to happen - damn it was much stronger than expected! I ended up using pieces of a plastic ice box to wedge inbetween cells to destroy the silicone. Worked ok, but took a while. Where the red silicone is visible was one of the split points. In this picture you can also see my 'bad boy charger' and my watercooled 2x0.25w 2ohm resistors working as a ~12W discharger. They're holding up
Before this I had a accident with the datacable balancing connector. It shorted within the connector, melting much of the plastic. Luckily they worked as fuses, the crappy cables - but god damn they went out with many bangs. Scary as hell. Never use data-transmission cables as balancing cables! You can see the black areas and some gaffa-tape that has melted. This was not the reason for the dead cell tho.
This is the bike as of today. It is missing top seal of battery pack, some wire shortening and some torque arms. I'm running it on 40A now. The bike is allmost all aluminium - with steel dropout inserts in the behind. Adding more beefy torque arms will be done before turning up the current to 70A.
A closer shot, I seriously need to get this cable mess a bit more stealthy. Consumption running 45kph is about 16whr/km. It climbs hills very good. Total bike weight has been prioritized, batt pack ~9kgs. Motor ~7-10kg and bike something along 10kgs. I'm 66kgs, so all in all it's very fast as it is now. 70kph is the most I've tested it to, it does not go much faster. I'll have to take it on the bathroom scale with me one time.
Just wanted to showoff my regen button as of now. I prefer not holding something in, and so this is perfect. A pushbutton (push to hold, push to unhold) that flows better with the bike will come in the future.
As for the name of the bike, it's cheesy - but I'm Norwegian and at times beardy, so why not :lol:
