Is over-discharge killing your remote site’s batteries?
It is no secret batteries are essential for the wireless communications industry, off-grid power systems, and various other industry segments where DC power is required. As demand for batteries increases, preventive maintenance to extend battery life and avoid undesirable power outage also becomes a more common practice. Sadly, even among professionals, there are those who are ready to install a battery module expecting it to operate with no maintenance until it reaches its average lifespan. Some even try to ignore the lifespan and continue to run it until it fails completely. Among all the overlooked parameters that ensure proper operation of a battery, such as its temperature and discharge cycles, one is particularly neglected, over-discharge.
BATTERIES ARE NOT DESIGNED TO LAST FOREVER, NOR DOES CURRENT TECHNOLOGY ALLOW FOR SUCH LUXURY. HOWEVER, HOW BADLY DOES OVER-DISCHARGING AFFECT YOUR BATTERY’S HEALTH AND LIFE-SPAN?
Generally manufacturers agree that a battery is considered to be dead when it reaches 80% of its original capacity. Over-discharging is one of the reasons for battery capacity to decrease. From small batteries such as Lithium-ion cell to large lead-acid batteries, no matter the size or application, these devices are susceptible to the harmful effects of operating when undercharged. Batteries that are drained too far are more likely to self-discharge (discharging even though no load is connected) and are more prone to experience an internal short circuit. In lead-acid batteries, for example, undercharged batteries suffer from sulfation of lead, which might severely damage battery plates and significantly reduce battery lifespan.
Why preventive maintenance is so important.
Modern emergency communication systems, for example, are frequently designed to operate at remote tower sites. This kind of remote infrastructure relies heavily on batteries and are often exposed to extreme weather and harsh climate conditions. In these systems, a significant percentage of the total operating costs can be due to battery replacement. Another example is battery strings used as a back-up for wireless network power systems. These batter banks are an expensive piece of the site’s equipment, typically engineered to endure up to 10 hours or more of autonomy in cases of power failure. Theses cost are even higher when proper battery maintenance practices are not used.
FOR THESE REASONS, DEVICES SUCH AS LOW VOLTAGE DISCONNECT SWITCHES ARE USED.
What are Low Voltage Disconnects?
These devices can automatically sense battery voltage levels and manage loads depending on individual battery conditions. Low voltage disconnect switches can be arranged to manage several loads, prolong battery life and prevent damage due to excessive discharge. Industrial versions can have an operating range that allows it to work with 12, 24 or even 48 volts DC, remote voltage sensing, and even password protection against possible non-authorized human interference.
Batteries are probably the most neglected devices in a standby power system, but when properly configured and installed, these disconnects might even extend batteries life beyond manufacturer expectations. Make low voltage disconnects a part of your site infrastructure to improve your preventive maintenance and ensure that your batteries are in top condition.