Microcontroller-based charging and monitoring controller for PV based dual battery sets

• Published in: Journal of energy storage Vol. 41; p. 102872
• Main Authors: KATCHE, Musong Louis, TSAFACK, Pierre, ARMAND, Tene Deffo Yves, TANYI, Emmanuel, DUCHARNE, Benjamin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2021
• Subjects: Battery charge controller; Microcontroller; MOSFETs; Switching time; Switching time; Microcontroller; Battery charge controller; MOSFETs
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2021.102872

•A control system to manage two sets of batteries with different or the same characteristics has been proposed.•The system provides the possibility of increasing the use time of a battery set in a solar photovoltaic system. This is because the new set of battery will be working with an additional capacity provided by the old battery set which will therefore reduce its number of charge and discharge cycles, hence extending its use time in the system.•Reduction of environmental impact posed during the disposal of batteries. This is because the rate at which batteries are disposed to the environment will be reduced as old batteries with incomplete capacity use will be reused in the system with the help of the designed circuit.•Power flow to the load during switching is not disrupted as observed during testing.•Faster switching times capable of maintaining power flow to the loads (AC and DC) are obtained. Sizing of battery storage capacity in solar photovoltaic (PV) systems is based on required autonomy. Most often, batteries used for such energy storage systems after some time come to a state where they can no longer sustain that required autonomy. When this happens, users can only completely replace the old battery set with new ones for a follow up of required system autonomy. That leads to a waste of the remaining active capacity of the batteries in addition to the fact that disposing the old set of battery also leads to environmental challenges. Moreover, charging and using batteries at the same time is not very good for the battery state of health as this stresses up the batteries hence reducing their life span. In this system proposal, in addition to avoiding simultaneous use and charging of battery set, we give possibility of longer use of the old battery set given that it is globally an addition of battery capacity of the two parallel monitored storage sets. The switching between energy storage sources while running each as a supply source at a time was done for different loads. The control of the switches is done using the PIC16F877A microcontroller while the IRF540 MOSFETs have been used as switches. With the static or direct current loads, a switching time of 8.5 ms was obtained while 33.06 ms was obtained for inductive loads; pending on eventual impact investigation of the above switching on AC loads, the switching time of the system is good enough to maintain supply to the loads during the supply sources interchange.