Solving a power source selection problem

Though there is a great variety of electrochemical power sources there is impossible to find the only one that meets all the requirements of autonomous power sources to any equipment for any purpose. There is always a task to find a compromise to implement the most important requirements with all the limitations the equipment for which a power source is selected has.

When choosing an electrochemical power source (EPS), it is necessary to consider the following moments determined by the operating conditions:

  • Discharge mode: continuous, intermittent, pulse;
  • Load type: constant current, constant resistance, constant power;
  • Operation mode of rechargeable power sources: cycling, buffer mode, storage with periodic recharging;

determined by the characteristics of power sources:

  • required power;
  • electrical characteristics of power source: maximum voltage at the beginning of the discharge, voltage stability under constant load, final discharge voltage, stability of characteristics under changing load modes;
  • design characteristics of power source: weight and overall dimensions, configuration, pin type;
  • service life;
  • storage life and storage conditions, permissible loss of capacity;
  • price initial for the cells and final for the battery pack (for entire service life with large number of operating cycles);
  • special requirements: reliability, resistance to mechanical stress, fire and explosion safety, availability of built-in devices to protect power source from critical electrochemical current states, the ability to replace, easy connection to the battery charger, charging mode for rechargeable power sources;

determined by environmental conditions:

  • environmental conditions: operating temperature range, storage temperature range, humidity.

To solve the problem of selecting a proper power source for a particular application is to determine the priority of criteria that should be taken into consideration.

It is not possible to give a definite algorithm to select a power source suitable for any project.
However, understanding the priority of requirements clearly, comparing main characteristics of power sources of different electrochemical systems makes possible to make a final decision and select the only one you need.