Building a battery box for my new Ebike Project

Lazaros

10 µW
Joined
Mar 26, 2015
Messages
5
Hi All
This is my experiences in making a battery enclosure for my new ebike build.
I had my last bike stolen just after building it. https://endless-sphere.com/forums/viewtopic.php?f=3&t=69277
When I finally got over the loss I embarked on a new build.

The new bike specs

The bike - Giant Anthem X3 2012
Motor - Crystalyte Rear HS4065RD
Controller - Infinion 12 FET Lyen Edition
Battery - High Energy 29E Samsung 50V 16.5Ah TRIANGLE PACK
Cycle Analyst V2.3[/list]

This time time I wanted to build an enclosure rather than using a bag for the Battery, the controller, motion alarm and all the wiring.
Since I have quite a bit of experience with making surfboards and on the sound advice of a mate I decided on making it out of fiberglass.
I settled on a fiberglass shell around a aluminium spine.
I wanted the aluminium spine so that I had something to bolt things to and to bolt the whole thing to the bike frame.

Here is how I went about it and the finished installed enclosure.
I forgot to photograph a few steps but important stuff is there.

Step 1: Measuring up the available space in the triangle

Anthem_X_3.jpg

I forgot to take a pic of the bike before I started the build but this is the same bike showing the available area I had to work with.

Step 2: Make a template.
ShapeTemplate.JPG

There was a bit of trimming to get it right so that the template sat neatly in the frame. I also allowed about 2mm all the way around the template for the fiberglass layers.

Step 3: Creating the Aluminium Spine.

I chose 50mm x 3mm aluminium bar for the spine. It is thick enough to be rigid but thin enough to shape.
50mmAluminium.jpg


Step 4: Shape the Aluminium Spine

I used the template as a guide to shape up the spine. I created the spine in 2 pieces so that I could get all the bends right and then joined the two pieces using more aluminium bar and pop rivets.
MetalFrame1.jpg

The final shape after much bending and filing. I bent the bar in metal vice using a hammer and block of wood.
MetalFrame2.jpg

Close up showing the join

Step 5: Making the foam molds for glassing
I used surfboard foam for the shape mold. A mate had a broken board which was perfect for what I needed.
Surfboard.jpg

I stripped off the old fiberglass and then cut up the foam to roughly the shape of the spine.
Using the spine as a template I drew a line inside the spine directly onto the blocks of foam.
This gave me a line for creating a rebate so that I could attach the foam to the spine.
FoamInsert1.jpg

I allowed about 20mm of foam to sit inside the spine.

Step 6: Attaching the foam sides.

I attached the two sides to the aluminium spine and held them in place using a hot glue gun and making sure none of the glue was on the outside.
Foam2.jpg

and
Foam3.jpg


Step 7: Shaping the foam sides
Using a combination of rasp, sandpaper and floor sanding screens I shaped up the sides and got to my final thickness (95mm).
Door1.jpg


Step8: Drawing up and cutting out the recess for the door on the side.
So I had this bright idea of having a door on one side for access (really wished I had measured up first.)
I drew up the door, allowed for the recess then and then used a router to create a recess.
Once that was done I cut out the foam I did not need.
Door2.JPG

The side with the door finished and ready for glassing.

Step 8: Glass the recess first.
I had to glass the recess the 'Door' would sit in first so that I had something to glass up to when I completed the shell.
DoorLipGlassing2.JPG

For this part of it I used UV catalyst instead of standard catalyst with the laminating resin.
I did this so that I had plenty of time to work getting the glass right and removing any bubbles from between the resin soaked fiberglass.
Once i had it right I took it out into the sun and the resin went off right away.
When the resin had hardened slightly I used a razor blade to cut away the excess fiberglass ready for the next step.

Step 9: Glass the rest of the enclosure

I used a combination of 4 ounce and six ounce weight fiberglass for the shell. Two layers of 6 ounce and two layers of 4 ounce.
This gave the shell strength but still remains light.
I had heaps of off-cut fiberglass material left over for a board I built which I cut it into strips.
Before laying down the fiberglass I coated the foam with soft furniture wax and a hair dryer to melt it into the foam as a releasing agent (It worked a treat!)
For this stage I used standard catalyst with the laminating resin so I had to work a bit quicker.
I did one layer at a time per side till I got to 4 layers all up.
Glassing1.JPG

Laying down the 6 ounce fiberglass

Glassing2.JPG

Taking special care around corners to add cuts so that the material will fold down and around the corners when the resin was brushed in.
Glassing3.JPG

Same around the nose of the enclosure

Step 10: Dig out all the foam and remove all the sharp edges

Once the resin had fully set I used a rasp to remove all the rough edges and prepare the surface for a rough sand.
Glassing4a.JPG


Glassing4.JPG


With the rasping a rough sanding out of the way it was time to dig out the foam.
It came out really easily once i made the first cuts into it.
With the foam out I also cleaned up the edges around the lip that the door would go onto.
Glassing6.JPG

The final enclosure

This where I had my F#@K!!!!!! moment.
I tried to fit the battery template I had made through the 'doorway'
PapPow.JPG

F@$%#^^*^$#@_+(+(!!!!!!!!!!!!!!

Step 11: Fixing my F@#kup

Since i obviously needed a lot more room I decided to go with a full side cover.
I carefully cut away the left side so that I ended up with a separate shell that fit perfectly to the rest of the enclosure.
Cover1.JPG


I then filled in the hole with more fiberglass.
Cover2.JPG


Once that was all done and the whole filled in I temporarily reattached the cover to the rest of the shell using a hot glue gun in a few spots to hold it in place.
I then ran around the spine of the enclosure with masking tape that came right up to the edge.
The final step was to lay down strips of glass to build a 'lip' on the lid that slid over the rest of the enclosure.
This is the final outcome of the that part of it.
CoverInside2.jpg


Step 12: Fitting the enclosure and marking out the mounting holes.
Fitting2.JPG

Fitting1.JPG


Step 13: Final sanding and cutting access holes and final filler resin.
This was the last of the really dirty work.
I sanded the whole enclosure with 100 and 120 grade sandpaper.
This is done to get rid of any major lumps and bumps and to round it all off.
It is also at this stage that any air pockets in the glass would appear.
I marked out and cut the holes needed for wiring, ignition key, frame mounts, and pre-charge switch.
With that all done the last thing to do was apply a coat of filler resin to fill in the scratches and provide a smooth surface for painting.
Cover4.JPG

The side cover with final filler coat applied

Step 14: Final fine sanding and painting.
The last step in making the enclosure was to sand the whole thing with 1000 and 1200 wet and dry sandpaper under flowing water.
Apply a coat of etch primer
Apply the final paint. I used acrylic car paint in a spray can for this part.
Painting1.JPG

Ignition key hole and front wire entry visible.

Painting2.JPG

The large hole is for the phase wires and hall sensor wires to the rear motor. The small rectangular hole is for the battery charging connectors.

Step 15: Installing the battery enclosure.
The enclosure is bolted to the frame down-tube through the two holes for the bottle holder with a 10mm spacer between the frame and enclusure.
A enclosure is fixed to the rear frame pole with a cable tie and held in place up front by a rubber grommet.
The whole structure is rock solid and there is no movement at all.

Instal1.jpg

The controller is bolted tight to the aluminium spine which helps dissipate heat.
The battery is held in place with a velcro strip and internal frame supports.
The motion alarm sensor is mounted up front and the speaker under the battery.


The side cover slips over the whole thing and is held in place with 5 hex head 5mm stubs that screw into the aluminium spine.

The finishedbuild
FinishedBike.jpg


LeftSide.jpg


LeftSideRear.jpg


RightFront.jpg


RightSideCloseUp.jpg


Switches.jpg


That's about it, now all that is left is to go for a ride!!!!
 
Nice one Laz, new bike looks great.

good to see you rebound from your loss.
 
Reads well.but getting no pics on my side.
 
Thanks for all the replies. I am really enjoying this build. Goes like a rocket and rides really well.
Not sure why images are not showing up. I have just had a look and they are all there.
 
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