I use a different type of charger,,,,, but very cheap and easy to come buy,,been using these for almost 18 years now lol,,,,,Okay what I use is the power supply from a old style desk top computer,,you will find it is a smart switching power supply so it will not come on,,, or will shut down in the case of a short,,,,That being said there are at least 50 power wires coming off of one of these and you could power something with each if you choose,,,The main power wires are already separated and color the same ,,,so red with red ,,black with black ,,blue with blue and so on very simple,,,remove the top cover and take a peak where all the wires are coming off of,,is a circuit board and the value of each wire is on the board,,,,12 volt ,,5 volt ,,3,3 volt and black is the ground,,I cut them and mount them to a bus terminal and put a wire on the bus terminal,,with a alligator clip for easy use,,,, I also ad a toggle switch as you will need to use two wires from a much smaller board as they are the wires that would have run to the on /off switch,,to turn the power supply on,,,I used one to power a CN radio and a linear,,which is a amplifier for that type of radio,,,But I use fans from a 12 volt fridge as they can be run on 3,3 volts no trouble,,I also use my power supply to recharge double AA battery and anything else I want,,I used one a while back to perform electrolysis and remove rust from old metals and such ,,,,I Tinker ,,you can run that 12 volt fan in your pict with 3 volts 5 volts or 12 as it is a brush less motor and will run based of the power input the higher the voltage the faster the fan spins,,in that type of motor