Limitations of Batteries in Powering
Wireless Sensors
Despite the tremendous advances in battery technology and the low
power designs used by leading WSN sensor manufacturers, batteries
do impose limitations for many customers.
1. Battery Life Degradation
at Desired Sensor Update Rates & Environmental Extremes 
The life of batteries powering any wireless sensors is decreased
as the data update rate increases. For many customers running the
update rates of their sensors at the desired level results in unacceptably
short battery life. This requires them to reduce the update rate
and forego the benefits of a more timely and robust data set for
the monitored process or equipment. Moreover, battery life is significantly
impacted by the local temperature environment. Low and high temperatures
found at industrial process facilities will degrade the power the
battery is able to deliver which exacerbate the life of batteries
operating at high data update rates.
2. Battery Replacement Frequency
For customers who do run their sensors at the higher update rates
they incur additional maintenance costs for more frequent battery
replacement. Unfortunately, sensor batteries expense are only one
component of the fully loaded cost of replacing them in wireless
sensor deployments. Very typically the storage and special handling
required of these products as well as the labor and operations disruption
associated with their replacement is several times the battery costs.
Over the life of the sensor can represent substantial expense and
dramatically erode the ROI of wireless sensor deployments.
For many customers neither of these compromises is
attractive.
3. Redundant Power Operation
There are also many instances where WSN’s are deployed in
sufficiently critical monitoring environments that require very
high levels of network and sensor reliability and data availability.
In these applications, providing redundant sensor power capability
wherein there are multiple independent power sources is a highly
desired and in many cases a necessary capability. Perpetua provides
solutions that uses energy harvesting and batteries to improve the
assurance of long-lived data availability.
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