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Lithium-Polymer Battery
Safety and Handling Instructions
Lithium-polymer batteries offer a variety of significant advantages over NiCd, NiMH and Li-Ion batteries for use in R/C electric
flight. It is very important to have a good understanding of the operating characteristics of LiPo batteries – especially how to
charge and care for them safely. Always read the specifications printed on the battery’s label and this instruction sheet in
their entirety prior to use. Failure to follow these instructions can quickly result in severe, permanent damage to the batteries
and its surroundings and even start a FIRE!
WARNING! Lithium-polymer batteries (LiPo) are ENTIRELY DIFFERENT than NiCd and NiMH batteries and must be handled
differently as well!! Great Planes® will not be held responsible for any and all incidental damages and bodily harm that may
result from improper use of ElectriFly™ brand lithium-polymer batteries. In purchasing these products, the buyer/user agrees
to bear all responsibilities of these risks and not hold ElectriFly, its distributors (owners and employees) and/or retailers
responsible for any accidents, injury to persons, or property damage. If you do not agree with these conditions, please return
the battery to the place of purchase.
Before and after every use of your LiPo battery, inspect all cells in the pack as much as possible to ensure no physical damage
or swelling is evident. Such signs can often indicate a dangerous problem exists with the battery that could lead to failure.
SAFECHARGE™ PROTECTION CIRCUIT
Select ElectriFly LiPo battery packs include a very small,
lightweight built-in “SafeCharge” circuit which constantly
monitors the voltage of each cell in the pack during charge. If
any cell in the pack reaches 4.20V (+/- 0.05V), the
SafeCharge circuit will automatically stop the charge process
for all cells in the pack entirely. The SafeCharge circuit
protects every cell in the pack from accidental overcharge, if
accidentally connected to a non-compatible charger, and
helps to make the pack more sturdy and rigid.
ElectriFly LiPo packs which contain the SafeCharge circuitry are
easily recognizable as they have a red 2-pin connector which is
used for charging the battery. Packs with the SafeCharge
circuitry are NOT designed for balancing of the individual cells in
the pack.
WARNING! NEVER apply a current of greater than 1.5
amps, or apply a voltage greater than 20V DC to the charge
lead of any ElectriFly LiPo battery which contains the built-in
SafeCharge circuitry. Otherwise, the SafeCharge circuit can
become damaged, preventing the battery from receiving a
proper charge and rendering all safety features inoperable.
BALANCING PLUGS
Select ElectriFly LiPo battery packs are configured for
balancing. Such packs do NOT include the SafeCharge
protection circuit, and do not include a red 2-pin connector as
described earlier. Instead, balancing packs include a unique
white connector which includes multiple wires (more than 2)
similar to the type of plug shown below.
WARNING! Packs with the balancing connector do NOT
include the SafeCharge protection circuit. NEVER attempt to
charge a pack which has the balancing connector with a
charger that is not capable of balance charging! Failure to do
so could result in damage to the battery and its surroundings,
and result in personal injury.
BATTERY VOLTAGES, RATINGS & APPLICATIONS
LiPo batteries can be assembled in many configurations.
Packs are most commonly found with cells assembled in
series, normally denoted with an “S”. For example, 3 cells in
series are often denoted as “3S”. Each LiPo cell has a
nominal voltage rating of 3.7V (with a minimum
recommended discharge voltage of 2.8V, and a maximum
charge voltage of 4.20V). The more cells assembled in
series, the higher the total voltage of the pack. But
assembling in series does not affect the overall rated
capacity of the pack as shown in the diagram on page 2.
Packs can also be assembled with cells in parallel, normally
denoted with a “P”. Adding cells in parallel increases the total
capacity and maximum discharge current of the pack, but
does not increase total pack voltage. Parallel packs are
almost always found with cells also assembled in series in
addition to parallel. For example, a common “series-parallel”
pack is “3S2P” as shown below, which is (a) 3 cells
assembled in series, plus (b) another 3 cells assembled in
series, and (c) both of those series configurations assembled
together in parallel. Most series-parallel packs are used for
larger aircraft where high current and capacity is needed.
Pack applications can depend on the number of cells in
series and/or parallel, but also pack capacity. Some of the
most common cell sizes and applications are:
CELL
CAPACITY # CELLS APPLICATION
640-750mAh 2S, 3S Slow flyers, foamies, small sport
aerobats and 3D’s
910-1200mAh 2S, 3S Foamies, small sport aerobats and
3D’s, small trainers
1500mAh 2S, 3S Bigger foamies, sport aerobats and
3D’s, trainers, small scale
2100mAh 2S, 3S Sport aerobats and 3D’s,
trainers, scale
3200mAh 2S, 3S Bigger sport aerobats and
3D’s, scale
IMPORTANT WARNINGS: Be sure to follow these important
warning statements regarding the charging of LiPo batteries:
• NEVER LEAVE A LIPO BATTERY UNATTENDED AT ANY
TIME WHILE BEING CHARGED!!
• NEVER charge a LiPo battery while it’s inside the model. A
hot pack could ignite wood, foam, plastic, etc.
• NEVER charge LiPo batteries with a NiCd or NiMH peak
charger! ONLY use a charger specifically designed for LiPo
batteries which can apply the “constant current / constant
voltage” charge technique (cc/cv). ElectriFly offers several
LiPo compatible chargers (www.electrifly.com) which can
be found at your local retailer.
• NEVER charge LiPo batteries at currents greater than the
“1C” rating of the battery (“C” equals the rated capacity of
the battery).
• NEVER allow LiPo cells to overheat at any time! Cells which
exceed 140°F (60°C) during charge can and USUALLY WILL
become damaged physically and possibly catch FIRE!! Always
inspect a battery which has previously overheated and do not
re-use if you suspect it has been damaged in any way.
• ALWAYS discontinue charging a LiPo immediately if at any
time you witness smoke or see the battery starting to swell
up. This may cause the battery to rupture and/or leak, and
the reaction with air may cause the chemicals to ignite,
resulting in fire. Disconnect the battery and leave it in a safe
fireproof location for approximately 15 minutes.
• ALWAYS charge a LiPo battery in a fireproof location,
which could be a container made of metal (such as an
ammunition box), ceramic tile, or a bucket of sand. ALWAYS
have an “ABC type” fire extinguisher available at all times.
Charging LiPo batteries:
1. Use a charge lead that directly mates to the connector on the
LiPo battery marked “CHARGE” or “TO CHARGER”.It is strongly
recommended to use pre-assembled charge leads which can be
found at most hobby retailers. Hand made connectors can be
unreliable and hazardous, providing poor physical and/or
electrical connections. ElectriFly’s “2-Pin/Banana Plug Charge
Adapter” (GPMM3105) is directly compatible with ElectriFly LiPo
batteries which have the red 2-pin charge connector (nonbalanced
packs).
CHARGING THE BATTERY
2. Connect the charge lead to the charger first. Then connect
the battery to the charge lead. NEVER connect the battery to
the charge lead if the charge lead is not connected to the
charger! WARNING! Never allow a battery’s positive and
negative leads to accidentally touch each other. This will
result in a short circuit and cause permanent damage to
your battery and or charger.
a. For
batteries having the RED 2-PIN CHARGE
CONNECTOR: Connect the red positive (+) lead to the
charger’s red positive (+) output jack, and the black negative ()
lead to the charger’s black negative (-) jack. ALWAYS charge
the battery through the connector that is marked “CHARGE” or
“TO CHARGER”. NEVER charge the battery through the
connector which goes to the ESC (marked “DISCHARGE” or
“TO ESC”). For safety purposes, do not cut or modify wires on
the battery in any way
.
b. For batteries having the BALANCING CONNECTOR: You
must know how many cells are in the battery pack, and then
choose an adapter lead which matches your pack. For
example, a 3-cell LiPo configured for balancing MUST use a
charge adapter which has enough wires to monitor the voltage
of all 3 cells in the pack (an adapter designed for 2 or 4 cells
will NOT work properly). A 2-cell LiPo configured for balancing
must use a balancing charge adapter that is designed for 2-cell
packs only, and so on. Failure to choose the proper balancing
adapter could result in improperly charged and improperly
balanced packs.
3. Set the charger’s output voltage to match the nominal
rated voltage of the entire LiPo battery pack. NEVER set the
charger to a voltage which is greater than the nominal
voltage rating of the LiPo pack or allow LiPo cells to
charge to greater than 4.20V per cell at any time!!
Overcharging LiPo cells usually will result in a permanent,
catastrophic failure in the LiPo cells which can result in
permanent damage to the battery and its surroundings, and
cause personal injury!
4. Set the charger’s output current to NO GREATER than the
“1C” rating of the battery. A battery’s “1C” rating equals the
amount of current needed to fully charge the battery in one
hour. For example, a battery with a capacity rating of
1200mAh has a 1C charge current rating of 1200mA (or 1.2
amps). A battery rated at 640mAh of capacity has a 1C rating
of 640mA (or 0.6 amps).
5. Command the charger to start the charge process.
6. ALWAYS monitor the battery and charger during the entire
charge process! NEVER leave the battery and charger
unattended during charge!
7. NEVER continue to charge LiPo batteries if the
charger fails to recognize full charge. Overheating or
swelling of the LiPo cells is an indication that a problem
exists and the batteries should be disconnected from the
charger immediately and placed in a fireproof location!!
8. NEVER apply a trickle charge to LiPo batteries.
9. Using a charger which has a battery temperature monitor
is very helpful for charging LiPo batteries. This can help to
ensure a full charge and also prevent unwanted heating at
the same time. Set the charger’s maximum battery
temperature to approximately 115°F (46°C).
CONNECTING TO AN ESC & DISCHARGING
IMPORTANT WARNINGS: Be sure to follow these important
warning statements regarding the discharging of LiPo batteries:
• NEVER LEAVE A LIPO BATTERY UNATTENDED AT ANY
TIME WHILE BEING DISCHARGED!!!
• ALWAYS discharge LiPo batteries in a fireproof location,
which could be a container made of metal (such as an
ammunition box) or on ceramic tile. Monitor the charge area
with a smoke or fire alarm, and have a lithium approved “ABC
type” fire extinguisher available at all times.
1. ALWAYS connect the battery’s lead marked
“DISCHARGE” or “TO ESC” to the electronic speed control.
NEVER attempt to connect the battery’s “CHARGE” lead to
the ESC.
2. It is strongly recommended to use an ESC which is
designed to handle the low voltage cutoff points for LiPo
batteries (always follow the instructions provided with the
ESC for proper operation). Discharging LiPo batteries below
2.5V per cell can cause permanent damage and limit the
number of times the battery can effectively be used again.
3. NEVER discharge LiPo batteries at currents which exceed
the discharge current rating of the battery as this can often
cause a cell to overheat. Do not allow a LiPo cell to exceed
140°F (60°C) during discharge.
BATTERIES INVOLVED IN A CRASH
It is very important to remember that crash damage to LiPo
batteries is much more dangerous than with NiCd or NiMH
cells. It might appear that no physical damage occurred to a
pack after a crash. However, LiPo batteries can often have a
delayed chemical reaction, and while they may appear to be
safe immediately after removing them from the crash they
can suddenly begin to smolder, emit smoke and catch fire
even after 30 minutes or an hour!! After a crash, remove the
LiPo battery from the model but DO NOT immediately place
it in a car, pocket or flight box. Instead, place the battery in a
fireproof location and observe it for safety reasons. If
possible, leave the battery in the safe location for 24 hours.
CAUTION! Cells may be hot! DO NOT allow the battery’s
internal electrolyte to get in the eyes or on skin – wash
affected areas with soap and water immediately if they come
in contact with the electrolyte. If electrolyte makes contact
with the eyes, flush with large amounts of water for 15
minutes and seek medical attention immediately!
Carefully inspect LiPo batteries which have been involved in
a crash for even the smallest of cracks, splits, punctures or
damage to the wiring and connectors.
STORAGE & TRANSPORTATION
• For long term storage it is recommended to charge the cells
fully, then discharge them to 50-60% of their capacity.
• Store battery at room temperature in cool or shaded area,
ideally between 40-80°F.Temperatures exceeding 170°F for
greater than 1 hour may cause damage to battery and
cause a fire.
• Do not expose battery packs to direct sunlight for extended
periods of time, or place in direct contact with any liquids. If
batteries come in contact with water, immediately dry the
battery with a clean towel.
• When transporting LiPo batteries, store them in a fireproof
container. NEVER leave batteries lying loosely anywhere in
the car (in the trunk, backseat, floor, etc.).
• ALWAYS
make sure all plugs / connectors on the LiPo
battery are covered, to prevent an accidental short. Small
sections of fuel tubing make good insulators.
• NEVER
leave LiPo batteries in the car indefinitely as
temperatures inside the vehicle can easily rise far in excess
of 120°F which could damage the battery.
HANDLING & FIRST AID INSTRUCTIONS
• NEVER allow LiPo batteries to be charged or discharged on
or near combustible materials, including paper, plastic,
carpets, vinyl, leather, wood, inside an R/C model or full-
sized automobile!
• NEVER
put loose cells or packs in the pocket of any
clothing!
• NEVER allow LiPo cells to come in contact with moisture or
water at any time.
• NEVER store batteries near an open flame or heater.
• NEVER assemble LiPo cells or pre-assembled packs together
with other LiPo cells/packs. Only a qualified battery assembly
company should assemble or modify LiPo batteries.
• NEVER allow LiPo cells to become punctured, especially by
metallic objects such as screwdrivers, T-pins, or hobby knives.
• NEVER charge or discharge a LiPo battery without having
an “ABC type” lithium approved fire extinguisher readily
available in case of a fire.
• DO NOT allow the battery’s internal electrolyte to get in the
eyes or on skin. Wash affected areas with soap and water
immediately if they come in contact with the electrolyte. If
electrolyte makes contact with the eyes, flush with large
amounts of water for 15 minutes and seek medical attention
immediately! If a battery leaks electrolyte or gas vapors, do
not inhale leaked material. Leave the area and allow the
batteries to cool and the vapors to dissipate. Remove
spilled liquid with absorbent and dispose.
• ALWAYS
provide adequate ventilation around LiPo
batteries during charge, discharge, and during storage. If a
battery becomes overheated IMMEDIATELY place it in a
fire-proof location until it cools.
• ALWAYS store LiPo cells/packs in a secure location away
from children.
• ALWAYS
make sure that metallic objects, such as
wristwatches, bracelets, or rings are removed from your
hands when handling LiPo packs. Accidentally touching
battery terminals to any such objects could create a short-
circuit condition and possibly cause severe personal injury.
DISPOSAL OF LIPO BATTERIES
Unlike NiCd batteries, lithium-polymer batteries are
environmentally friendly. For safety reasons, it’s best that
LiPo cells be fully discharged before disposal (however, if
physically damaged it is NOT recommended to discharge
LiPo cells before disposal - see below for details). The
batteries must also be cool before proceeding with disposal
instructions. To dispose of LiPo cells and packs:
1. If any LiPo cell in the pack has been physically damaged,
resulting in a swollen cell or a split or tear in a cell’s foil
covering, do NOT discharge the battery. Jump to step 5.
2. Place the LiPo battery in a fireproof container or bucket
of sand.
3. Connect the battery to a LiPo discharger. Set the discharge
cutoff voltage to the lowest possible value. Set the discharge
current to a C/10 value, with “C” being the capacity rating of
the pack. For example, the “1C” rating for a 1200mAh battery
is 1.2A, and that battery’s C/10 current value is (1.2A / 10)
0.12A or 120mA. Or, a simple resistive type of discharge load
can be used, such as a power resistor or set of light bulbs as
long as the discharge current doesn’t exceed the C/10
value and cause an overheating condition. For LiPo packs
rated at 7.4V and 11.1V, connect a 150 ohm resistor with a
power rating of 2 watts (commonly found at Radio Shack) to
the pack’s positive and negative terminals to safely discharge
the battery. It’s also possible to discharge the battery by
connecting it to an ESC/motor system and allowing the motor
to run indefinitely until no power remains to further cause the
system to function.
4. Discharge the battery until its voltage reaches 1.0V per cell
or lower. For resistive load type discharges, discharge the
battery for up to 24 hours.
5. Submerse the battery into bucket or tub of salt water. This
container should have a lid, but it does not need to be airtight.
Prepare a bucket or tub containing 3 to 5 gallons of cold
water, and mix in 1/2 cup of salt per gallon of water. Drop the
battery into the salt water. Allow the battery to remain in the
tub of salt water for at least 2 weeks.
6. Remove the LiPo battery from the salt water and place it in
the normal trash.
Hobby Services
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(217) 398-0007
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