NABCEP Battery Focus Test with all Correct & 100%
Verified Answers |Latest Update |Already Graded A+
Finding the Critical Design Month ✔Correct answer-1) Determine Efficiency of PV System
2) Determine Average Peak Sun Hours for Each Month
3) Multiply #1 and #2 for each month
4)Determine Average Daily Loads for Each Month
5) Divide Figures from #3 by #4
The largest number is the critical design month
How do you size a load ✔Correct answer-Find the critical design month and multiply it for 120%
- this should satisfy the load without going beyond a 80% discharge.
Voltage limitations for battery banks in residential PV ✔Correct answer-Must be LESS THAN 50
volts. --> Almost always 48 Volts
Nominal Battery Voltage ✔Correct answer-The voltage of the battery based on the number and
types of cells in the battery.
NOTES:
The most common nominal cell voltages are as follows:
- Lead Acid: 2 Volts per Cell
- Alkali Systems: 1.2 Volts per Cell
- Li-ion Systems: 4 Volts per Cell
Sealed Battery (Sealed Cell) ✔Correct answer-A sealed battery has no provision for the addition of
water or electrolyte or for external measurement of electrolyte specific gravity.
Racks and Trays must be treated to be.... ✔Correct answer-resistance to deteriorating action by
electrolytes
Temperature Affects on Discharge Rate and Capactiy ✔Correct answer-
What is the started discharge rate for PV systems ✔Correct answer-C/20 (this is a 20 hour
discharge rate)
What temperature are batteries rated for? ✔Correct answer-78 Degrees Fahrenheit
What happens when ambient temperature exceeds the battery's rated temperature? ✔Correct
answer-When the temperature is above 78 degrees the battery life will reduce drastically.
What happens when ambient temperature are below the battery's rated temperature? ✔Correct
answer-When the temperature is below 78 degrees the battery life will extend drastically.
How does temperature factor into sizing a battery bank? ✔Correct answer-Oversizing a battery
bank will increase the life of all batteries by preventing overdischarge due to temperature.
, Optimal Depth of Discharge should average about 25%
Whats the temperature coefficient for battery systems? ✔Correct answer-For every 2 Volts there is
a -.005V/degree Celsius adjustment factor.
You could also look at it this way:
-.0025 Volts per Volt per degree Celsius
Or even like this....
-1%/Degree Celsius
Whats the best way to test the battery's true health? ✔Correct answer-A Load Tester
Functions of a Charge Controller ✔Correct answer-1) Protects Batteries from Overcharging
- MPPT Controller converts excess input voltage into current
- Standard controllers lose excess input voltage (above battery voltage)
2) Diversion - Diverts excess energy to a competent load once batteries have reached a full state of
charge
3) Load Control - Disconnects and reconnects loads to protect battery from over discharge
4) Linear Charge Controllers: Used to maximize current to a load and provide a constant voltage such
as a well pump.
How do you size a charge controller ✔Correct answer-STC Rated PV Array Watts = Battery System
Operating Voltage x Charge Controller Rated Output Current
When are charge controllers not needed... ✔Correct answer-When
1) the PV Source Circuit is matched to the voltage and current requirements of the interconnected
battery cells
and
2) the maximum charging current multiplied by 1 hour is less than 3% of the rated battery capacity
expressed in amp hours (or as recommended by the battery manufacturer).
EXAMPLE:
200 Amp-hours battery can have an unregulated input current of no more than 6 amps.
Learn? ✔Correct answer-PVIP 6 - Slide 17
Sizing Output of MPPT Charge Controllers ✔Correct answer-Based on Maximum rated continuous
output current of charge controller for selected output voltage range.
The voltage range will be based on the maximum voltage output of the charge controller for a
selected output voltage range.
Verified Answers |Latest Update |Already Graded A+
Finding the Critical Design Month ✔Correct answer-1) Determine Efficiency of PV System
2) Determine Average Peak Sun Hours for Each Month
3) Multiply #1 and #2 for each month
4)Determine Average Daily Loads for Each Month
5) Divide Figures from #3 by #4
The largest number is the critical design month
How do you size a load ✔Correct answer-Find the critical design month and multiply it for 120%
- this should satisfy the load without going beyond a 80% discharge.
Voltage limitations for battery banks in residential PV ✔Correct answer-Must be LESS THAN 50
volts. --> Almost always 48 Volts
Nominal Battery Voltage ✔Correct answer-The voltage of the battery based on the number and
types of cells in the battery.
NOTES:
The most common nominal cell voltages are as follows:
- Lead Acid: 2 Volts per Cell
- Alkali Systems: 1.2 Volts per Cell
- Li-ion Systems: 4 Volts per Cell
Sealed Battery (Sealed Cell) ✔Correct answer-A sealed battery has no provision for the addition of
water or electrolyte or for external measurement of electrolyte specific gravity.
Racks and Trays must be treated to be.... ✔Correct answer-resistance to deteriorating action by
electrolytes
Temperature Affects on Discharge Rate and Capactiy ✔Correct answer-
What is the started discharge rate for PV systems ✔Correct answer-C/20 (this is a 20 hour
discharge rate)
What temperature are batteries rated for? ✔Correct answer-78 Degrees Fahrenheit
What happens when ambient temperature exceeds the battery's rated temperature? ✔Correct
answer-When the temperature is above 78 degrees the battery life will reduce drastically.
What happens when ambient temperature are below the battery's rated temperature? ✔Correct
answer-When the temperature is below 78 degrees the battery life will extend drastically.
How does temperature factor into sizing a battery bank? ✔Correct answer-Oversizing a battery
bank will increase the life of all batteries by preventing overdischarge due to temperature.
, Optimal Depth of Discharge should average about 25%
Whats the temperature coefficient for battery systems? ✔Correct answer-For every 2 Volts there is
a -.005V/degree Celsius adjustment factor.
You could also look at it this way:
-.0025 Volts per Volt per degree Celsius
Or even like this....
-1%/Degree Celsius
Whats the best way to test the battery's true health? ✔Correct answer-A Load Tester
Functions of a Charge Controller ✔Correct answer-1) Protects Batteries from Overcharging
- MPPT Controller converts excess input voltage into current
- Standard controllers lose excess input voltage (above battery voltage)
2) Diversion - Diverts excess energy to a competent load once batteries have reached a full state of
charge
3) Load Control - Disconnects and reconnects loads to protect battery from over discharge
4) Linear Charge Controllers: Used to maximize current to a load and provide a constant voltage such
as a well pump.
How do you size a charge controller ✔Correct answer-STC Rated PV Array Watts = Battery System
Operating Voltage x Charge Controller Rated Output Current
When are charge controllers not needed... ✔Correct answer-When
1) the PV Source Circuit is matched to the voltage and current requirements of the interconnected
battery cells
and
2) the maximum charging current multiplied by 1 hour is less than 3% of the rated battery capacity
expressed in amp hours (or as recommended by the battery manufacturer).
EXAMPLE:
200 Amp-hours battery can have an unregulated input current of no more than 6 amps.
Learn? ✔Correct answer-PVIP 6 - Slide 17
Sizing Output of MPPT Charge Controllers ✔Correct answer-Based on Maximum rated continuous
output current of charge controller for selected output voltage range.
The voltage range will be based on the maximum voltage output of the charge controller for a
selected output voltage range.
