The last step is to insulate & pad the battery box and finally install the battery.
Tools needed in this step
- Double sided tape
- Straight edge
- Scissors and/or knife
- Old PCBs
- Packing Foam
- Wire grommet
- Saw (to cut PCBs to size)
- Rotary Tool
This is the box I bought for the battery. It’s in fact slightly bigger than needed, but it fits on my bike OK and I didn’t want to wait for a custom box to be made.
I started writing how this step wasn’t as dangerous… but there are still lots of ways to short the battery or otherwise injure yourself. Always use common sense and respect the tools and materials you are using.
I’m going to put the cable through a plastic wire grommet in the left hole and block off the right hole. This box is a generic box so it has a bunch of holes, most of which I don’t need and will cover up.
The first thing I did was tape a layer of packing foam to the lid of the box.
There were some extra holes at the bottom of the box, and I wanted something strong to insulate the bottom of the box. I had a bunch of PCBs around so I used those. I put them at the bottom of the box and at the front. The sides have no holes to cover up and the foam will be sufficient insulation.
I used a extra cell to size the inside of the box. It was much easier than test fitting the whole battery. Since the box is bigger than needed, I ended up using quite a bit of foam. It won’t hurt anything.
The last step was to install the battery in the insulated box. Make sure you plan ahead how you will pas the wires through the hole in the box. My wires all have bullet connectors on them, making it easy to install the wires.
Here is the finished battery. Time for a charge and a test ride.
I did test the battery and it works very well. I got 23km on my first ride, which I decent considering how heavy my bike is and the size of the motor. I can easily pick up the battery in one hand making it easy to bring in the house to charge. My first electric bike had an over 30kg lead acid battery pack. Many bikes around here still use lead acid battery packs. They are super cheap and have decent power, but they are way too heavy and unless you want to save a few bucks, LiPo or LiFe is the way to go. This pack is comparable in power and just little under 6kg.