study of MAH battery capacity with flight time calculation and battery connection

1. Name : Pranali Ravindra Patil. Teacher name : Krishna
Pandey
Roll no. : A43.
In this experiment, mAH battery capacity as well as flight
time calculation has been studied.
The mAH battery capacity with flight time calculation is the
first part of the experiment.
Whereas, second part contain battery connection module.
To studied about mAh theory ideal quadcopter drone
application has been analysed. In
addition, LiPO battery as an energy source has been explored
for the drone application. The
detail explanation of the experiment has been discussed in
upcoming sections.
A. Part_1: -
Study of mAH battery capacity with flight time calculation

2. 2. Methodology:
• Are LiPo Battery Safe?
There are many reasons why LiPo batteries might catch on fire.
That tends to only happen
when you don’t handle them properly or when they are
physically damaged. If you’re gentle
with your batteries you should be okay.
• The Basics about LiPo Batteries for Mini Quad: -
Lithium polymer batteries (LiPo) have high energy density,
high discharge rate and light
weight which make them a great candidate or RC applications.
By learning the basics about
LiPo batteries, you will be able to read and understand their
specifications.

3. • Battery Voltage and Cell Count (S)
LiPo batteries exist in cells, each LiPo cell has a nominal voltage
of 3.7V. If higher voltage is
required, these cells can be connected in series to form a single
battery.
We don’t normally refer to the battery voltage, but how many cells
in the battery, or how many
“S”.
1S = 1 cell = 3.7V
2S = 2 cells = 7.4V
3S = 3 cells = 11.1V

4. 4S = 4 cells = 14.8V
5S = 5 cells = 18.5V
6S = 6 cells = 22.2V
For example, we call a 14.8V battery a “4-cell” or “4S” battery.
Voltage affects brushless motors RPM directly, therefore you
could use higher cell count
batteries to increase your quadcopter’s speed if your motor/ESC
and other electronics support
higher voltage. But a battery with more cells of the same capacity
is heavier since it contains

5. more cells. To make a 4S 1000mah battery, you could simply
combine two 2S 1000mah, or
one 3S 1000mah with an 1S 1000mah.
Note: - Nominal voltage for LiPo battery cell is 3.7V. However,
it’s not the voltage of the
battery either when it’s fully charged or fully discharged. The
number is come up by
manufacturers, and It’s near the middle of safe voltage range, so I
guess that kind of makes
sense.
LiPo battery is designed to operate within a safe voltage range,
from 3V to 4.2V. Discharging
below 3V could cause irreversible performance lost and even
damage to the battery. Over-
charging above 4.2V could be dangerous and eventually cause fire.
However, it’s advisable to
stop discharging when it reaches 3.5V for battery health reasons.
For example, for a 3S Lipo,
the max voltage is 12.6V, and you should land when the voltage
reaches 10.5V (at 3.5V per
cell).
• LiPo Battery Capacity and Size
The capacity of a LiPo battery is measured in mAh (milli-amp
hours). “mAh” is basically an

6. indication of how much current you can draw from the battery for
an hour until it’s empty.
For example, for a 1300 mAh Lipo, it would take an hour to be
completely discharged if you
draw a constant 1.3A current from it. If the current draw doubles
at 2.6A, the duration would
be halved (1.3/2.6=0.5). If you draw 39A of current non-stop, this
pack would only last 2
minutes (1.3/39=1/30 of an hour).
Increasing your battery capacity might give you longer flight time,
but it will also get heavier
in weight and larger in physical size. There is a trade-off between
capacity and weight, that
affects flight time and agility of the aircraft.
How to choose battery for longer flight time: -
Higher capacity could also give you higher discharge current as
you will see in the next section.
Note that, 1000mAh = 1Ah.
• C Rating (Discharge Rate)
Lipo batteries for quadcopters these days all come with a C rating.
By knowing the C rating
and capacity of a battery, we can in theory calculate the safe,
continuous max discharge
current of a LiPo battery.
C-Rating is yet another crucial aspect that need to be checked
before you decide to settle

7. for any battery for your quadcopter. Batteries with an extremely
low discharge rating often
result in under-performance. However, this does not necessarily
imply that those with the
hightest C-Rating are the best since they are heavier. You need to
get a battery whose C rating
is convenient for your quadcopter.
Maximum Discharge Current = C-Rating *
Capacity
For example, an 1300mAh 50C battery has an estimated
continuous max discharge current
of 65A.
If C rating is too low, the battery will have a hard time delivering
the current to your motors,
and your quad will be under powered. You could even damage the
battery if current draw
exceeds safety rating. When C rating is higher than what’s
required, you won’t gain much
performance improvement. Instead, the battery would be heavier
and you will be carrying extra
weight that reduces your flight time.
• Flight Time Calculation
Quadcopter flight times = (Battery Capacity *
Battery Discharge /Average Amp Draw) *60

8. a) Battery Capacity: For calculator you have to take the
battery’s capacity in amp hours.
To convert from mAh to Ah, battery capacity divide by 1000. For
instance,
1800mAh/1000=1.8Ah.
b) Battery Discharge: It’s common practice to not discharge
your LiPo batteries below
20% mAh during flight; In other words, the effective capacity is
only 80% that can be
used during flight time. For instance, 1.8Ah*0.8=1.44A
c) Average Amp Draw: Before quadcopter battery
calculator you work out the average
amp draw, you have to know two things, one is about your
carrying weight of your
quadcopter which include battery weight. Another thing is the
parameters of quadcopter
motor. Therefore, read your motor instructions, you have to know
how many amps one
motor will be draw to produce 100g of thrust? This is the key
points in the calculation
of Average Amp Draw.
Calculate: - For example, I have a LiPO battery 3s 3300mAh, I
calculated the average amp
draw of quadcopter to be around 20 amps, and I am making an
assumption that 80% of battery
capacity will is used, then the quadcopter flight time is ?.

9. Quadcopter flight times = (3300/1000mAh) * 80% / 20 amps *60
minutes = ?
B. Part_2: - Battery connections
• Connectors
There are several battery connectors, the entire process of
soldering battery connectors can be
tiring and hectic at times. It is always a good idea for one to
maintain a given connector type.
This way, you are able to make fast and quick connections without
having to waste time doing
numerous “trial and error” procedures.

10. • Connection
It’s always important to fly with a full battery. Since you have no
way of knowing the battery’s
current charge during a flight, always error on the side of caution.
The battery will fit
comfortably in between the upper and lower frame, as shown in
Figure 5. Use zip ties or Velcro
straps to hold the battery in place. It’s very important the battery
does not fall off the craft
during flight.

11. Summary:
In this experiment, the study of mAH battery capacity with flight
time calculation and battery
connection has been carried out. In the first part of the
experiment, mAH battery capacity and
flight time calculation has been carried out. In the second part of
the experiment, battery

12. connection with the system using power distribution system has
been depicted (Figure 5 to 8).
In addition, a complete LiPo battery connection with the system
has been shown in Figure 7.