The battery can be mounted on the:
Rear Rack Mounting
Some conversion kits have their batteries inside a bag. The bag can be put on the handlebar or can be mounted on the rear rack.
Racks come in many styles so each installation will be different depending on the type of rack used. Make sure your battery is secure and snug so it will not move when riding.
The controller is either:
There should be a recommended place for mounting the controller but use your own judgment to figure out what is the best place. The best and most common places are the:
If the controller is placed near the seat-post it can get in the way when you will try to quick-release the saddle for example. Pay attention that the controller doesn't not interrupt to any other part. Pay extra attention to this in a case of a folding bicycle.
Don't forget that eventually wiring from the handlebars, motor and battery will all cross through the controller so make sure that they can reach the controller location before doing any wiring.
Consider the following in relation to your bicycle before buying any kit:
Many self-build kits come with huge batteries too heavy to carry that mount on a locked rear rack. This gives the obvious appearance of an electric bike and may be an invite to thieves or vandals. Think about how you plan to use your bike and whether you will need to leave it outside. Fitting a smaller battery has the advantage that it can be mounted in an inconspicuous bike bag which can then be removed from the bike whenever necessary.
- There are rear carriers that can hold one or two batteries at either side of the rear wheel.