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BATTERIES: CELLS IN COMBINATION
You are likely aware that electrochemical batteries and cells come in a variety
of sizes and shapes, and that many electronic devices require more than one
individual cell or battery. In this activity, you will investigate differences in cells
and a variety of cell arrangements in order to discover a few reasons why
different numbers and arrangements may be needed.
Use the voltmeter to determine the electric potential difference (“voltage”) of
each of these DRY CELLS. See if the cell will light a common Christmas tree bulb.
Dry
Cell
AAA
AA
Electric Potential
Difference, Volts
Lights Christmas
tree bulb?
Dry
Cell
C
D
Electric Potential
Difference, Volts
Lights Christmas
tree bulb?
From these measurements, it is apparent that the __________________________ of the cell does not affect its
__________________________________ nor its ability to _________________________________________.
 Based on your previous investigations, what determines the electrical potential difference of an
electrochemical cell?
 What do you think determines whether or not an electrochemical cell will light a Christmas tree bulb?
Now connect several D-cells into the series, parallel, and combination circuits shown and use the voltmeter to
determine the electric potential difference of each BATTERY.
A Battery of D-Cells in Series (cells are connected positive to negative in sequence):
= _________ V
= _________ V
= _________ V
 What happens to the electric potential difference (“voltage”) when cells are added in series?
 Why would you put cells in series?
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A Battery of D-Cells in Parallel (cells are connected pos. to pos. and neg. to neg):
= ______ V
= ______ V
= ______ V
 What happens to the electric potential difference (“voltage”) when cells are added in parallel?
 Why would you put cells in parallel?
A Battery of D-Cells in Combination:
= ______ V
= ______ V
= ______ V
= ______ V
 What can you say about combining cells in combination?
 Why would you put cells in combination?
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Many times people wonder if it makes a difference where you connect the voltmeter leads when the circuit
elements are connected in parallel. To find out, connect four cells in parallel as before. Connect the positive
and negative leads of the voltmeter at the locations specified below and record the electric potential differences.
A
E
AE = ______ V
AG = ______ V
AF = ______ V
AH = ______ V
B
F
BE = ______ V
BG = ______ V
BF = ______ V
BH = ______ V
C
G
CE = ______ V
CG = ______ V
CF = ______ V
CH = ______ V
D
H
DE = ______ V
DG = ______ V
DF = ______ V
DH = ______ V
What did you find out?
Car batteries are typically comprised of six separate wet cells arranged in series. They are all housed in a
single plastic case and give an overall battery voltage of 12 V.
 What does this total voltage and cell arrangement imply about each individual wet cell that makes up this
battery?
 Why is this different from the common dry cell?
 Tractors, motorcycles, riding mowers, and golf carts sometimes require 8 V batteries and sometimes
require 6 V batteries. How many wet cells are needed to make each of these batteries?
 Why do you suppose transportation vehicles use wet cell batteries instead of dry cell batteries?
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