Paper Battery PowerResponder User manual

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Proprietary!Information©!Paper!Battery!Company!!!!!!www.paperbatteryco.com!
For!more!details!on!applications!or!to!obtain!samples,!contact:![email protected]!
PowerResponder™!Application!Note!#150301!
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PowerResponder™,Fast,Charger,Kit,,
Reference,Design,and,Quick,Start,Guide!!
The Paper Battery company is pleased to provide a fast charger evaluation platform for the PowerResponderTM
line of supercapacitors. The kit contains a wall adapter, fast charge board and reference circuit diagrams as
requested and includes two PowerResponder™ cells. The kit will enable customers to quickly and effectively
evaluate PowerResponderTM and provide design guidance when integrating PowerResponderTM cells into their
products.
NOTE: This kit cannot be used for charging lithium-ion batteries, which are unsafe under fast charge conditions
Theory of operation:
The PowerResponderTM product line is a hybrid, high energy supercapacitor and can be charged at much higher
current in less time than conventional lithium ion batteries. The Paper Battery Company has data on cycle life
impact showing thousands of cycles with less than 20% loss of capacitance. PowerResponderTM devices fail in
open circuit mode after a gradual, easily measureable, and thus predictable, decrease in capacity. There is no
risk of flammability or thermal run-away from the PowerResponderTM cells.
Our fast charger kit includes a standard off-the-shelf 36 Watt AC line adaptor providing 18 Volts at 2 Amperes.
The charging subsystem is a microprocessor controlled CC/CV buck converter with an integrated LED fuel gauge.
Block Diagram of the Fast Charger Board:
Current and voltage set points are configurable with the onboard potentiometers. The default configuration is 5A

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Proprietary!Information©!Paper!Battery!Company!!!!!!www.paperbatteryco.com!
For!more!details!on!applications!or!to!obtain!samples,!contact:![email protected]!
PowerResponder™!Application!Note!#150301!
!
Constant Current/ 4.0V Constant Voltage – corresponding to 20 Watts of charging power.
The plot below illustrates a constant current fast charge of our 350 Farad PowerResponderTM product at 5A. A full
charge is achieved in 105 seconds.
Note that the PowerResponderTM products should not be discharged below 2.5V which will result in premature
degradation of the device. Our usable energy numbers in product specifications are always quoted from 2.5V to
4.0V to accurately represent the available energy.
Multiple PowerResponderTM cells can be charged in parallel as this rapid charge system is capable of delivering
up to 10A continuous and 16A intermittently for multiple cells in charged in parallel. Cell + and Cell – output
connectors are provided as large plated-through holes to solid copper conducting- planes.
When initially powered on the LED fuel gauge will be a dim blue color. Pressing the charge button will initiate a
charge sequence whereby the microprocessor will use the constant current charging set point as determined by
the CC potentiometer while observing the open cell voltage at 1 second intervals to determine when 4.0V has
been achieved. This method allows automatic charge termination regardless of the PowerResponderTM capacity
attached for charging.
During charging, the fuel gauge will display a red to green color graduated indicator ranging from 2.5V (all LEDs
off) to 4.0V (all LEDs on). At completion of full charge, the LEDs will return to the blue color state.
A note on conventional Constant Current/Constant Voltage charging:
Traditionally CC/CV charging has been employed as a very reliable method of assuring the most energy stored in
a battery or capacitor device.
The reason for the Constant Voltage interval is largely due to the device’s internal resistance. At a constant
current, Ohm’s law dictates that the internal resistance will create a voltage proportional to the applied current. As
charging current increases, the effect of this voltage differential becomes more prevalent.

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Proprietary!Information©!Paper!Battery!Company!!!!!!www.paperbatteryco.com!
For!more!details!on!applications!or!to!obtain!samples,!contact:![email protected]!
PowerResponder™!Application!Note!#150301!
!
By way of example, the PowerResponderTM 350 Farad product has a series resistance of 80 milliOhms. If we
charge the device at 5 Amperes, and use a cutoff voltage of 4.0 Volts – the charger will terminate charge at 3.6
Volts owing to the 0.4 Volts developed across the cell’s internal resistance. Ohm’s law states that V=IR, so 5
Amperes * 0.08 Ohms yields 0.4V of potential. Upon removal of the charging current, the cell voltage will drop to
a lower voltage which is dependent on the amount of charge that was provided to the device.
This short constant current charge is then followed by a constant voltage interval which assures that the device
stores the maximum amount of usable energy. In applications where the capacity of the device being charged is
unknown, the fast charge board adds additional charge and monitors cell voltage until the desired top-off value is
achieved. For lithium batteries, this constant voltage charge stage can take several hours, but for the
PowerResponder™ product, a few more seconds of constant current are adequate to attain full charge.
Specific implementation:
The Paper Battery Company’s fast charger board is a buck converter with an external current sensing loop
imposed onto the controller such that the output voltage collapses to maintain constant current.
The fast charge board is provided with a 36 Watt AC adaptor, but it can also be powered by any 9-20VDC source
with sufficient current rating for the desired charging power.
The image below illustrates the actual charging loop implementation: The specific buck converter used here has a
5 amp internal switch. It should be noted that any buck converter or other type of regulator can easily be used.
Linear regulators are not recommended as the power dissipation in the device may become prohibitively high.
The microprocessor is strictly optional in any implementation. The main purpose of the microprocessor in this
system is to turn off charging after the desired voltage has been achieved. In typical applications,
PowerResponder™ cells will be charged up to between 3.8V and 4.0V.

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Proprietary!Information©!Paper!Battery!Company!!!!!!www.paperbatteryco.com!
For!more!details!on!applications!or!to!obtain!samples,!contact:![email protected]!
PowerResponder™!Application!Note!#150301!
!
The following table summarizes the key features of the fast charger board:
Minimum
Nominal
Maximum
Input voltage range
6VDC
18VDC
20VDC
Input current range
0A
2A
5A
Output voltage range
0
4.0VDC
19V
Output Current Range
0
8A
16A
The diagram below shows the board as shipped with all relevant input and outputs labeled.