Super capacitor in IoT devices enhance battery

#Announcement(IoTStack) [ via IoTForIndiaGroup ]

GSM Protocol Requires 2A Pulse for 0.6msec Every 4.2msec. GSM / GPRS modules are implemented mostly in M2M applications. These GSM/GPRS modules use either Lithium Ion rechargeable battery’s or Lithium Thionyl Chloride Battery non-rechargeable – primary.
Case of Lithium Ion battery:
It is recommended to use a non Aqueous Ultra Low ESR Super Capacitor with lower or equal ESR to the internal resistance of the Lithium Ion Battery (~ 150 mΩ).During the short GSM pick pulse of 2A, the Lithium Ion will deliver a maximum of 1A only.This reduction will prevent serious “Voltage Recovery” effect (after high current pulse, battery voltage does not achieve it’s previous value).

Adding these Super Capacitors will aid preventing the battery to enter “Voltage Recovery”. Without a Super Cap the battery alone needs to provide 2A. This high current causes early discharge of the battery and prevents it getting closer to its shutdown threshold.Between the GSM pulses during 4.2msec the battery can smoothly charge the Super Cap.

Electronics devices, which are designed for short term operation and stay long in stand-by mode need huge energy impulse immediately after wake-up. Emergency alarm systems, RFID transponders, GPS tracking devices, smart meters’ read-out electronics or the recently obliged E-CALL systems of passenger vehicles need a battery with stable voltage, low leakage, being able to pump huge momentary charge into the system.

These requirements are often realized by integrating super-capacitors, that have ten or even hundred times higher energy density than normal electrolytic capacitors, their charge and discharge times are also shorter, and tolerate much more cycles that e.g. rechargeable batteries.

Supercap’s operation is mainly based on electrostatic charge, however there are some special devices, like EVE Energy’s own patented SPC devices featuring chemical working principle. They are mainly in use as a part of a special battery pack. This paper introduces the advantages of such system.

SPC device
The super pulse capacitors produced by EVE are momentary high-current discharge devices that can operate in the operational temperature range of -40°C to +85°C. SPC’s unique chemical lithium structure is based on EVE’s own patents. One of this areas is the gas metering, where SPC with its ATEX approval is an ideal solution for energizing smart-meter’s readout, as the safety valves make the device explosion proof.

The cell voltage is 3.6V, and no passivation appears, which other lithium battery families are suffering from. The self discharge remains under 2%, which makes it possible to stay long in stand-by more and activate fast to pump momentary large charge into the circuit.

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