Load test or capacity test of a GMDSS battery

Shipaxis Technical Services


LOAD TEST OR CAPACITY TEST OF A GMDSS BATTERY (24VDC)

Over the years of experience as a radio surveyor, it has been observed that the most common mistake that the ship staff does is the maintenance of the GMDSS battery (reserve source). This emergency source is often misunderstood for compliance. In a nutshell let us have a look into what is this emergency source is all about:


As per SOLAS regulations it is mandatory for all vessels built after 1995 to have on board an emergency generator. Older ships might have an emergency generator or a battery bank as emergency source. When we speak of sources of energy it is as below:

  1.  Main source of energy - Main Generator.
  2. emergency source - This supplies power to emergency lights and other applications on board and it is  not the one supplying power to GMDSS equipment.
  3. The reserve source of energy is normally a 24V DC - lead acid battery which primarily caters to the communication equipment needs only. The AH capacity of this battery is normally in the range of 180 - 220 Ah (Ampere hour).
  4. This reserve source should be in a position to supply 24V DC for a period of 1 - 6 hours depending on the availability of Emergency generator. It should be 1 hour if the vessel is fitted with emergency generator or 6 hours if it is not fitted with emergency generator.
  5. The efficiency of the battery depends on many factors, viz: regular charging on/off load test etc. 
During Radio Survey or GMDSS SRC, it is most common that  the Class surveyor is questioning about the log book of GMDSS battery and it is often seen that a sheet of paper is being produced (by the electrical officer) as a log.This is to be avoided as far as possible. At this stage, let us skip the rig morale of going through the procedures of maintaining the battery as most of the people are aware of the same. 

The video below demonstrates in brief as to how to calculate the load of the battery. 



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Comments

  1. ManasiMarch 14, 2023 at 10:09 AM

    reat post.Thanks for sharing.
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