The DC power source of a low frequency RFID reader must be electrically quiet with very little ripple. Some power supplies generate too much noise which causes the read range to be shorter and can cause the reader to overheat.
All power sources need to be properly sized by knowing the operating voltage and amperage requirements of the reader. The actual amperage for a particular system will vary depending on the antenna and other factors. The voltage and effective amperage is measured by the datalogger to calculate power requirements.
When setting up a new site it is sometimes easier to use a battery during the installation stage and once the system is running, measure the amperage before configuring the power source.