Is it possible to make my own charging cable?
To be able to do this job, you need to know the following: 


Voltage required by the device: you need to stick to the exact rating.
Current required by the device: to choose a charger that can at least supply that amount of current.
Polarity of charging terminal: so you don't mix the positive and negative and damage the device.
Have or be able to get a very similar terminal in shape to make a secure connection.


To know this information, you can either find it on the device, user manual of the device or just Google it for that specific model.