February 2011 41
by Don Apostolico
Myths
and facts
popular
power option
about a
This arTiCle will address misinformation and
issues relative to the concerns that many aeromodelers have
regarding the operation of Lithium-ion (Li-ion) and Li-Poly
batteries and the practices that modelers use that cause
batteries to prematurely fail, self-combust, or vent (swell up
like a balloon).
Let’s think about the hundreds of millions of people
around the world who are, at this moment, safely operating
Lithium-powered consumer electronics products without
issue. These items include, but are not limited to, cell
phones, MP3 players, iPods, laptop computers, some
Dremel tools, some GPS systems, numerous garden power
tools, Sears battery-powered drills, hearing aids, digital
cameras, and camcorders.
Contrast that mental image with the modeling
community, which is required to charge Lithium batteries in
ammunition or ceramic safety boxes—in case the batteries
blow up or vent while charging—to prevent houses from
burning down.
Why can Grandma Jones, who doesn’t know a volt from
an amp, charge a consumer-product 5000 mA Lithium
battery on the coffee table in the living room, but John Q.
Modeler has to put the battery in a fortified enclosure? The
reasons will become clear as you continue to read.
The current aeromodeling mind-set regarding the danger
of Lithium batteries has been created by no information,
misinformation, product misuse, uninformed opinions,
reporting the symptom rather than diagnosing the
problem, and blaming the battery rather than identifying
the cause.
Blaming the battery has resulted in the impression that
it causes most incidents or accidents. How many cell
phones, digital cameras, or Dremel tools have you heard
about that have blown up and burned down houses? To
make matters worse, inaccurate stories have been passed
around so many times that, for some, symptoms have
become the cause, and fiction has become fact.
I am not claiming that incidents don’t occur; I’m
informing you that Lithium is one of many power sources
that can combust or vent if operated incorrectly. Improper
charging and handling, random failures, and lack of
understanding of batteries often results in mishaps.
Monitoring and caution are the prudent courses of action
for all batteries—not only Li-ion or Li-Poly.
Consumers’ Vs. Modelers’ Charging Requirements: As
far as I’ve seen, aeromodelers are the only consumers
lawyers require to charge batteries in a safety container,
located outside of the aircraft. That practice is not wrong,
but general consumer-product lawyers do not require the
same charging procedures for other goods that use
Lithium batteries.
Above: Judy Apostolico holds the author’s scratch-built, 30%-scale, 48-pound Cessna 310R. It features a JR radio and servos, two JR
receivers, sequencing gear doors, rivets, panel lines, full interior, twin Lithium batteries, and regulators. Don has used Li-ion batteries
in all of his giant-scale models since 1996.
Li t h i u m
B a t t er i es
L i iu att 02sig2_00MSTRPG.QXD 12/20/10 10:35 AM Page 41
42 MODEL AVIATION
Photos by the author
The high-quality Hobbico Accu-Cycle Elite is capable of
charging a variety of batteries. Many battery failures occur
when users select the wrong charge type for a given battery.
The ElectriFly Triton from Great Planes is a quality unit that can
charge numerous types of batteries. However, it does not have a
balance board bus.
The three-output Fromeco Ion Cube is a DC-input, plug-andplay
unit that accommodates only Li-ion and LiFe batteries.
It’s safe and handy to use to charge giant-scale models with
multiple packs.
You must use correctly programmed, compatible chargers
for the specific battery size, milliamp, cell, and wiring
configuration. Do not leave batteries unattended while charging,
and remember that a slower charge rate is battery-friendly
compared to fast-charging.
Practicing these simple procedures for all types of batteries
will reduce the likelihood of an accident. The user is always
responsible for determining whether or not information
presented is applicable to a particular set of circumstances.
If batteries are handled safely, charged properly, and used
correctly, mishaps can be reduced to those statistically
insignificant random failures that any electronic component
experiences from time to time. MA
—Don Apostolico
Caution!
Some consumer products use more current flow than our
giant models do. However, the general consumer industry
rarely sees cases of Lithium-powered products exploding
and catching fire, resulting in damaged homes. The basic
difference is in the way the public uses and charges batteries
compared to how modelers use and charge their batteries.
Some readers might be able to cite an exception. My Ni-
Cd-powered transmitter was destroyed when it caught fire
while sitting on the workbench with the switch in the off
position. And a customer’s NiMH battery self-combusted on
the counter by the cash register.
A battery with any chemistry can catch fire because of
faulty circuit boards or shorting. Let’s not blame the battery
if something else caused the fire.
Why do lawyers require aeromodelers but not the public
to charge batteries in a safe box? The answers are simple.
Members of the public who use a Lithium-powered
product are required, by virtue of its design, to use the
correct (supplied) charger. It is programmed to the correct
charge rate and calibrated to the proper milliamperage/
voltage and proper cell configuration for the particular
battery. This might not be the case with modelers and
their products.
Those in the public realm who use cell phones do not
charge them with a Great Planes Triton or other high-quality
adjustable charger. Grandma Jones can’t dial in the wrong
voltage/amperage, select the wrong battery chemistry, or use
the wrong number of battery cells or incompatible wiring
configurations. By contrast, modelers have the ability to
vary charging and usage parameters that can cause fires.
A lack of operational knowledge makes any mechanical
or electrical item more hazardous for an individual to
operate. The good news is that safety issues can be
addressed through education, so that the operators can avoid
conditions that result in unfortunate incidents.
Following are the major operational issues with
aeromodelers’ Lithium batteries.
• Compatibility: Not all Lithium chargers are compatible
with all brands of Lithium batteries. If you have doubts
about your charger, check the instructions or call the charger
manufacturer before plugging the unit into your battery.
• Dumb or Smart Chargers: If you use a dumb Lithium
charger to charge a dumb Lithium battery, it will catch fire;
02sig2_00MSTRPG.QXD 12/20/10 11:27 AM Page 42
February 2011 43
This 7.4-volt Li-ion battery with two
cells wired in series should be charged
as a two-cell pack at rate of 1C or less.
This is a 7.4-volt Li-ion battery with four
cells. Two series-wired groups are
connected in parallel, to double the
output capacity. It should still be charged
at the 7.4-volt level.
don’t blame the battery. A “dumb”
charger has no ability to regulate the
charge rate. A “dumb” battery has no
smart circuitry onboard to regulate the
incoming charge rate.
Ni-Cd is a dumb battery. Some
Lithium batteries are dumb and some
are smart.
If the battery has an integrated
circuit, it is “smart.” The chip regulates
the charge rate to properly charge the
battery and includes a circuit breaker.
Smart batteries have fallen into
disfavor with many modelers who fly
large aircraft. Imagine performing a
high-G Snap Roll or Blender and
having the circuit breaker blow; down
goes a $6,000 airplane.
If a charger allows a modeler to
select the number of cells, voltage and
current rates, battery chemistry, time,
or cutoff voltage, it is “smart.”
• Wiring configuration: How is your
battery wired? Not all Lithium types
are wired the same. Some are wired in
series and some are wired in series and
parallel. You must know what
configuration you have to safely charge
your batteries, or a fire could result.
Four-cell Lithiums wired in series
parallel are charged as a two-cell on the
7.4-volt setting. If you charge a fourcell,
7.4-volt series parallel pack on the
four-cell (14.8 volt) setting, you will
start a fire.
This is an operator issue—not a
battery issue. Those who are less
experienced in series and parallel
electrical-wiring configuration should
familiarize themselves with basic
electrical data, to get it right the first
time.
Make sure you know and
understand what you are charging
before you make the connections.
Don’t try it to see if it works.
• Current settings: I take regular calls
from aeromodelers who use high-end
programmable chargers, who think that
they have defective Lithium batteries.
Although a new product can be
defective, it is more likely that that
buyer has used the wrong charge
procedure, rates, voltage, or
amperage, or the Ni-Cd setting
instead of Lithium.
Among other mistakes, it is
common to enter the wrong decimal
rate when setting the adjustable
charge rate on a high-end unit.
Instead of dialing in a .5-amp (500
mAh) charge rate, a user might
program 5.0 amps (5000 mAh).
If that is done, the battery could
blow up like a balloon or catch fire a
few minutes into the charge cycle,
and the operator might think that the
battery is defective. A lucky modeler
catches the fire before it burns the
house down. An unlucky modeler’s
house is destroyed.
This is an operator issue. Make
sure that you correctly program the
many variables on a unit.
• High Charge Rates: Heat is the
enemy of all batteries. Many Lithium
units are rated for a 1C (capacity)
charge rate; a 2000 mAh pack 1C
charge rate is 2000 mAh (2 amps). A
Li-ion battery charged at 2000 mAh
will get warm or hot.
Why cook your battery? Do you
fast-charge your cell phone?
A slower charge rate is batteryfriendly,
because it does not generate
the heat that faster charge rates do.
Excess heat makes all battery types
less reliable, shortens their lifespans,
and makes them more prone to
malfunctions caused by internal
changes that occur when they are
charged at high rates.
Li-Poly batteries seldom get
warm if charged at 1C unless there
is a problem. Should that happen,
take the hint and discontinue using
that pack.
My 40% airplanes have 5200 mAh
Li-ion Fromeco packs wired series and
parallel. I charge them at 1 amp. It
takes two to three hours instead of 60
minutes to charge a pack, but if a
flying session ends at 7 p.m., what’s
the point of using a fast charge rate and
cooking the batteries if I’m not going
to go out again until the next day?
Charged and used correctly, I
typically get roughly three years of use
(approximately 1,200 flights) from my
packs. Those who cook their batteries
by fast-charging might blow through
them in a few months or a few charge
cycles and believe that they have a
defective product.
Using multichargers with multiple
chemistry settings and putting a dial on
the wrong chemistry type are common
mistakes that create problems. Make
Operational
Experience
Don’s Hobby Shop has sold and
equipped its own giant-scale models
with Lithium batteries since 1996.
Between then and now I have observed
that danger comes not from using Liion
batteries, but from misusing Lithium
batteries and chargers.
Major mistakes include:
• Using incompatible chargers.
• Setting incorrect charge rates.
• Employing “dumb” chargers with
“dumb” batteries.
• Selecting the wrong settings on
adjustable “smart” chargers.
• Exceeding the current-draw discharge
capacity of a battery.
• Fast-charging batteries faster than the
rated capacity.
• Causing vibration damage by
improperly restraining batteries.
• Subjecting equipment to shock impact
(crashes).
The result of the preceding errors is
often a fire, which many times is a
symptom of aproblem rather than the
problem. A battery might be labeled as
defective, while the true cause of the
mishap often goes unidentified.
I have seen numerous examples of
misuse throughout the 20 years my
store has been in business. The issues
are not new, nor are they limited to
Lithium battery technology. MA
—Don Apostolico
02sig2_00MSTRPG.QXD 12/20/10 11:29 AM Page 43
sure you understand the programming
procedure of your charger before you
connect it.
Using a Ni-Cd or NiMH “dumb” wall
charger or other mismatched charger on a
Lithium battery is a gross mistake, and
there are others. If you exceed the
discharge rate limits of a pack, you will
probably experience venting or a fire.
Purchase a pack that is capable of
delivering the current requirements for
your model.
44 MODEL AVIATION
This fire issue is analogous to burning up a
new digital servo on throttle and then blaming
it for being faulty, when it was the operator
who programmed the servo travel to overdrive
the throttle stops. Then the uninformed
recommend that digital servos not be used on
throttle, because they burn up.
I recommend the opposite. Purchase
digital servos and set them up correctly
(with a current meter) so that they don’t
burn out!
Having flown with and sold Lithium
batteries since 1996 and learning that
handling, storing, and charging any battery
incorrectly can lead to problems, I
recommend exercising caution when
charging or using all batteries.
Be careful when doing your homework;
there is a lot of bad information out there.
Don’t confuse excellent pilot skills with
technical expertise.
Just because your well-meaning friend
can torque roll or says it’s true doesn’t
make it right. You, as the operator, must
take the responsibility to get it right.
Have fun and fly safely. MA
Don Apostolico
[email protected]
Sources:
Don’s Hobby Shop
(800) 972-6273
www.donshobbyshop.com
Fromeco Scale Avionics
(503) 715-0020
www.fromeco.org
Great Planes
(217) 398-8970
www.greatplanes.com
Batteries that are improperly secured
and shift position in an airplane can
contact the plywood formers or a shard of
CA or epoxy glue, which can puncture the
cell; that shorts or vents the battery.
Sometimes batteries are hard-mounted
without foam, and the same damage
occurs. These are operator-setup issues.
A battery that has received impact
damage should never be reused. Internal
damage can cause it to short and cause a
fire. The short might not occur
immediately; you might get several flights
and charge cycles before the final failure
occurs, and then another house or aircraft
is lost.
Experience with tens of thousands of
customers at Don’s Hobby Shop
throughout the years, helping modelers
buy equipment or troubleshoot, has shown
that the overwhelming majority of these
venting problems and fires are caused by
the operator—not the battery.
02sig2_00MSTRPG.QXD 12/20/10 11:30 AM Page 44
Edition: Model Aviation - 2011/02
Page Numbers: 41,42,43,44
Edition: Model Aviation - 2011/02
Page Numbers: 41,42,43,44
February 2011 41
by Don Apostolico
Myths
and facts
popular
power option
about a
This arTiCle will address misinformation and
issues relative to the concerns that many aeromodelers have
regarding the operation of Lithium-ion (Li-ion) and Li-Poly
batteries and the practices that modelers use that cause
batteries to prematurely fail, self-combust, or vent (swell up
like a balloon).
Let’s think about the hundreds of millions of people
around the world who are, at this moment, safely operating
Lithium-powered consumer electronics products without
issue. These items include, but are not limited to, cell
phones, MP3 players, iPods, laptop computers, some
Dremel tools, some GPS systems, numerous garden power
tools, Sears battery-powered drills, hearing aids, digital
cameras, and camcorders.
Contrast that mental image with the modeling
community, which is required to charge Lithium batteries in
ammunition or ceramic safety boxes—in case the batteries
blow up or vent while charging—to prevent houses from
burning down.
Why can Grandma Jones, who doesn’t know a volt from
an amp, charge a consumer-product 5000 mA Lithium
battery on the coffee table in the living room, but John Q.
Modeler has to put the battery in a fortified enclosure? The
reasons will become clear as you continue to read.
The current aeromodeling mind-set regarding the danger
of Lithium batteries has been created by no information,
misinformation, product misuse, uninformed opinions,
reporting the symptom rather than diagnosing the
problem, and blaming the battery rather than identifying
the cause.
Blaming the battery has resulted in the impression that
it causes most incidents or accidents. How many cell
phones, digital cameras, or Dremel tools have you heard
about that have blown up and burned down houses? To
make matters worse, inaccurate stories have been passed
around so many times that, for some, symptoms have
become the cause, and fiction has become fact.
I am not claiming that incidents don’t occur; I’m
informing you that Lithium is one of many power sources
that can combust or vent if operated incorrectly. Improper
charging and handling, random failures, and lack of
understanding of batteries often results in mishaps.
Monitoring and caution are the prudent courses of action
for all batteries—not only Li-ion or Li-Poly.
Consumers’ Vs. Modelers’ Charging Requirements: As
far as I’ve seen, aeromodelers are the only consumers
lawyers require to charge batteries in a safety container,
located outside of the aircraft. That practice is not wrong,
but general consumer-product lawyers do not require the
same charging procedures for other goods that use
Lithium batteries.
Above: Judy Apostolico holds the author’s scratch-built, 30%-scale, 48-pound Cessna 310R. It features a JR radio and servos, two JR
receivers, sequencing gear doors, rivets, panel lines, full interior, twin Lithium batteries, and regulators. Don has used Li-ion batteries
in all of his giant-scale models since 1996.
Li t h i u m
B a t t er i es
L i iu att 02sig2_00MSTRPG.QXD 12/20/10 10:35 AM Page 41
42 MODEL AVIATION
Photos by the author
The high-quality Hobbico Accu-Cycle Elite is capable of
charging a variety of batteries. Many battery failures occur
when users select the wrong charge type for a given battery.
The ElectriFly Triton from Great Planes is a quality unit that can
charge numerous types of batteries. However, it does not have a
balance board bus.
The three-output Fromeco Ion Cube is a DC-input, plug-andplay
unit that accommodates only Li-ion and LiFe batteries.
It’s safe and handy to use to charge giant-scale models with
multiple packs.
You must use correctly programmed, compatible chargers
for the specific battery size, milliamp, cell, and wiring
configuration. Do not leave batteries unattended while charging,
and remember that a slower charge rate is battery-friendly
compared to fast-charging.
Practicing these simple procedures for all types of batteries
will reduce the likelihood of an accident. The user is always
responsible for determining whether or not information
presented is applicable to a particular set of circumstances.
If batteries are handled safely, charged properly, and used
correctly, mishaps can be reduced to those statistically
insignificant random failures that any electronic component
experiences from time to time. MA
—Don Apostolico
Caution!
Some consumer products use more current flow than our
giant models do. However, the general consumer industry
rarely sees cases of Lithium-powered products exploding
and catching fire, resulting in damaged homes. The basic
difference is in the way the public uses and charges batteries
compared to how modelers use and charge their batteries.
Some readers might be able to cite an exception. My Ni-
Cd-powered transmitter was destroyed when it caught fire
while sitting on the workbench with the switch in the off
position. And a customer’s NiMH battery self-combusted on
the counter by the cash register.
A battery with any chemistry can catch fire because of
faulty circuit boards or shorting. Let’s not blame the battery
if something else caused the fire.
Why do lawyers require aeromodelers but not the public
to charge batteries in a safe box? The answers are simple.
Members of the public who use a Lithium-powered
product are required, by virtue of its design, to use the
correct (supplied) charger. It is programmed to the correct
charge rate and calibrated to the proper milliamperage/
voltage and proper cell configuration for the particular
battery. This might not be the case with modelers and
their products.
Those in the public realm who use cell phones do not
charge them with a Great Planes Triton or other high-quality
adjustable charger. Grandma Jones can’t dial in the wrong
voltage/amperage, select the wrong battery chemistry, or use
the wrong number of battery cells or incompatible wiring
configurations. By contrast, modelers have the ability to
vary charging and usage parameters that can cause fires.
A lack of operational knowledge makes any mechanical
or electrical item more hazardous for an individual to
operate. The good news is that safety issues can be
addressed through education, so that the operators can avoid
conditions that result in unfortunate incidents.
Following are the major operational issues with
aeromodelers’ Lithium batteries.
• Compatibility: Not all Lithium chargers are compatible
with all brands of Lithium batteries. If you have doubts
about your charger, check the instructions or call the charger
manufacturer before plugging the unit into your battery.
• Dumb or Smart Chargers: If you use a dumb Lithium
charger to charge a dumb Lithium battery, it will catch fire;
02sig2_00MSTRPG.QXD 12/20/10 11:27 AM Page 42
February 2011 43
This 7.4-volt Li-ion battery with two
cells wired in series should be charged
as a two-cell pack at rate of 1C or less.
This is a 7.4-volt Li-ion battery with four
cells. Two series-wired groups are
connected in parallel, to double the
output capacity. It should still be charged
at the 7.4-volt level.
don’t blame the battery. A “dumb”
charger has no ability to regulate the
charge rate. A “dumb” battery has no
smart circuitry onboard to regulate the
incoming charge rate.
Ni-Cd is a dumb battery. Some
Lithium batteries are dumb and some
are smart.
If the battery has an integrated
circuit, it is “smart.” The chip regulates
the charge rate to properly charge the
battery and includes a circuit breaker.
Smart batteries have fallen into
disfavor with many modelers who fly
large aircraft. Imagine performing a
high-G Snap Roll or Blender and
having the circuit breaker blow; down
goes a $6,000 airplane.
If a charger allows a modeler to
select the number of cells, voltage and
current rates, battery chemistry, time,
or cutoff voltage, it is “smart.”
• Wiring configuration: How is your
battery wired? Not all Lithium types
are wired the same. Some are wired in
series and some are wired in series and
parallel. You must know what
configuration you have to safely charge
your batteries, or a fire could result.
Four-cell Lithiums wired in series
parallel are charged as a two-cell on the
7.4-volt setting. If you charge a fourcell,
7.4-volt series parallel pack on the
four-cell (14.8 volt) setting, you will
start a fire.
This is an operator issue—not a
battery issue. Those who are less
experienced in series and parallel
electrical-wiring configuration should
familiarize themselves with basic
electrical data, to get it right the first
time.
Make sure you know and
understand what you are charging
before you make the connections.
Don’t try it to see if it works.
• Current settings: I take regular calls
from aeromodelers who use high-end
programmable chargers, who think that
they have defective Lithium batteries.
Although a new product can be
defective, it is more likely that that
buyer has used the wrong charge
procedure, rates, voltage, or
amperage, or the Ni-Cd setting
instead of Lithium.
Among other mistakes, it is
common to enter the wrong decimal
rate when setting the adjustable
charge rate on a high-end unit.
Instead of dialing in a .5-amp (500
mAh) charge rate, a user might
program 5.0 amps (5000 mAh).
If that is done, the battery could
blow up like a balloon or catch fire a
few minutes into the charge cycle,
and the operator might think that the
battery is defective. A lucky modeler
catches the fire before it burns the
house down. An unlucky modeler’s
house is destroyed.
This is an operator issue. Make
sure that you correctly program the
many variables on a unit.
• High Charge Rates: Heat is the
enemy of all batteries. Many Lithium
units are rated for a 1C (capacity)
charge rate; a 2000 mAh pack 1C
charge rate is 2000 mAh (2 amps). A
Li-ion battery charged at 2000 mAh
will get warm or hot.
Why cook your battery? Do you
fast-charge your cell phone?
A slower charge rate is batteryfriendly,
because it does not generate
the heat that faster charge rates do.
Excess heat makes all battery types
less reliable, shortens their lifespans,
and makes them more prone to
malfunctions caused by internal
changes that occur when they are
charged at high rates.
Li-Poly batteries seldom get
warm if charged at 1C unless there
is a problem. Should that happen,
take the hint and discontinue using
that pack.
My 40% airplanes have 5200 mAh
Li-ion Fromeco packs wired series and
parallel. I charge them at 1 amp. It
takes two to three hours instead of 60
minutes to charge a pack, but if a
flying session ends at 7 p.m., what’s
the point of using a fast charge rate and
cooking the batteries if I’m not going
to go out again until the next day?
Charged and used correctly, I
typically get roughly three years of use
(approximately 1,200 flights) from my
packs. Those who cook their batteries
by fast-charging might blow through
them in a few months or a few charge
cycles and believe that they have a
defective product.
Using multichargers with multiple
chemistry settings and putting a dial on
the wrong chemistry type are common
mistakes that create problems. Make
Operational
Experience
Don’s Hobby Shop has sold and
equipped its own giant-scale models
with Lithium batteries since 1996.
Between then and now I have observed
that danger comes not from using Liion
batteries, but from misusing Lithium
batteries and chargers.
Major mistakes include:
• Using incompatible chargers.
• Setting incorrect charge rates.
• Employing “dumb” chargers with
“dumb” batteries.
• Selecting the wrong settings on
adjustable “smart” chargers.
• Exceeding the current-draw discharge
capacity of a battery.
• Fast-charging batteries faster than the
rated capacity.
• Causing vibration damage by
improperly restraining batteries.
• Subjecting equipment to shock impact
(crashes).
The result of the preceding errors is
often a fire, which many times is a
symptom of aproblem rather than the
problem. A battery might be labeled as
defective, while the true cause of the
mishap often goes unidentified.
I have seen numerous examples of
misuse throughout the 20 years my
store has been in business. The issues
are not new, nor are they limited to
Lithium battery technology. MA
—Don Apostolico
02sig2_00MSTRPG.QXD 12/20/10 11:29 AM Page 43
sure you understand the programming
procedure of your charger before you
connect it.
Using a Ni-Cd or NiMH “dumb” wall
charger or other mismatched charger on a
Lithium battery is a gross mistake, and
there are others. If you exceed the
discharge rate limits of a pack, you will
probably experience venting or a fire.
Purchase a pack that is capable of
delivering the current requirements for
your model.
44 MODEL AVIATION
This fire issue is analogous to burning up a
new digital servo on throttle and then blaming
it for being faulty, when it was the operator
who programmed the servo travel to overdrive
the throttle stops. Then the uninformed
recommend that digital servos not be used on
throttle, because they burn up.
I recommend the opposite. Purchase
digital servos and set them up correctly
(with a current meter) so that they don’t
burn out!
Having flown with and sold Lithium
batteries since 1996 and learning that
handling, storing, and charging any battery
incorrectly can lead to problems, I
recommend exercising caution when
charging or using all batteries.
Be careful when doing your homework;
there is a lot of bad information out there.
Don’t confuse excellent pilot skills with
technical expertise.
Just because your well-meaning friend
can torque roll or says it’s true doesn’t
make it right. You, as the operator, must
take the responsibility to get it right.
Have fun and fly safely. MA
Don Apostolico
[email protected]
Sources:
Don’s Hobby Shop
(800) 972-6273
www.donshobbyshop.com
Fromeco Scale Avionics
(503) 715-0020
www.fromeco.org
Great Planes
(217) 398-8970
www.greatplanes.com
Batteries that are improperly secured
and shift position in an airplane can
contact the plywood formers or a shard of
CA or epoxy glue, which can puncture the
cell; that shorts or vents the battery.
Sometimes batteries are hard-mounted
without foam, and the same damage
occurs. These are operator-setup issues.
A battery that has received impact
damage should never be reused. Internal
damage can cause it to short and cause a
fire. The short might not occur
immediately; you might get several flights
and charge cycles before the final failure
occurs, and then another house or aircraft
is lost.
Experience with tens of thousands of
customers at Don’s Hobby Shop
throughout the years, helping modelers
buy equipment or troubleshoot, has shown
that the overwhelming majority of these
venting problems and fires are caused by
the operator—not the battery.
02sig2_00MSTRPG.QXD 12/20/10 11:30 AM Page 44
Edition: Model Aviation - 2011/02
Page Numbers: 41,42,43,44
February 2011 41
by Don Apostolico
Myths
and facts
popular
power option
about a
This arTiCle will address misinformation and
issues relative to the concerns that many aeromodelers have
regarding the operation of Lithium-ion (Li-ion) and Li-Poly
batteries and the practices that modelers use that cause
batteries to prematurely fail, self-combust, or vent (swell up
like a balloon).
Let’s think about the hundreds of millions of people
around the world who are, at this moment, safely operating
Lithium-powered consumer electronics products without
issue. These items include, but are not limited to, cell
phones, MP3 players, iPods, laptop computers, some
Dremel tools, some GPS systems, numerous garden power
tools, Sears battery-powered drills, hearing aids, digital
cameras, and camcorders.
Contrast that mental image with the modeling
community, which is required to charge Lithium batteries in
ammunition or ceramic safety boxes—in case the batteries
blow up or vent while charging—to prevent houses from
burning down.
Why can Grandma Jones, who doesn’t know a volt from
an amp, charge a consumer-product 5000 mA Lithium
battery on the coffee table in the living room, but John Q.
Modeler has to put the battery in a fortified enclosure? The
reasons will become clear as you continue to read.
The current aeromodeling mind-set regarding the danger
of Lithium batteries has been created by no information,
misinformation, product misuse, uninformed opinions,
reporting the symptom rather than diagnosing the
problem, and blaming the battery rather than identifying
the cause.
Blaming the battery has resulted in the impression that
it causes most incidents or accidents. How many cell
phones, digital cameras, or Dremel tools have you heard
about that have blown up and burned down houses? To
make matters worse, inaccurate stories have been passed
around so many times that, for some, symptoms have
become the cause, and fiction has become fact.
I am not claiming that incidents don’t occur; I’m
informing you that Lithium is one of many power sources
that can combust or vent if operated incorrectly. Improper
charging and handling, random failures, and lack of
understanding of batteries often results in mishaps.
Monitoring and caution are the prudent courses of action
for all batteries—not only Li-ion or Li-Poly.
Consumers’ Vs. Modelers’ Charging Requirements: As
far as I’ve seen, aeromodelers are the only consumers
lawyers require to charge batteries in a safety container,
located outside of the aircraft. That practice is not wrong,
but general consumer-product lawyers do not require the
same charging procedures for other goods that use
Lithium batteries.
Above: Judy Apostolico holds the author’s scratch-built, 30%-scale, 48-pound Cessna 310R. It features a JR radio and servos, two JR
receivers, sequencing gear doors, rivets, panel lines, full interior, twin Lithium batteries, and regulators. Don has used Li-ion batteries
in all of his giant-scale models since 1996.
Li t h i u m
B a t t er i es
L i iu att 02sig2_00MSTRPG.QXD 12/20/10 10:35 AM Page 41
42 MODEL AVIATION
Photos by the author
The high-quality Hobbico Accu-Cycle Elite is capable of
charging a variety of batteries. Many battery failures occur
when users select the wrong charge type for a given battery.
The ElectriFly Triton from Great Planes is a quality unit that can
charge numerous types of batteries. However, it does not have a
balance board bus.
The three-output Fromeco Ion Cube is a DC-input, plug-andplay
unit that accommodates only Li-ion and LiFe batteries.
It’s safe and handy to use to charge giant-scale models with
multiple packs.
You must use correctly programmed, compatible chargers
for the specific battery size, milliamp, cell, and wiring
configuration. Do not leave batteries unattended while charging,
and remember that a slower charge rate is battery-friendly
compared to fast-charging.
Practicing these simple procedures for all types of batteries
will reduce the likelihood of an accident. The user is always
responsible for determining whether or not information
presented is applicable to a particular set of circumstances.
If batteries are handled safely, charged properly, and used
correctly, mishaps can be reduced to those statistically
insignificant random failures that any electronic component
experiences from time to time. MA
—Don Apostolico
Caution!
Some consumer products use more current flow than our
giant models do. However, the general consumer industry
rarely sees cases of Lithium-powered products exploding
and catching fire, resulting in damaged homes. The basic
difference is in the way the public uses and charges batteries
compared to how modelers use and charge their batteries.
Some readers might be able to cite an exception. My Ni-
Cd-powered transmitter was destroyed when it caught fire
while sitting on the workbench with the switch in the off
position. And a customer’s NiMH battery self-combusted on
the counter by the cash register.
A battery with any chemistry can catch fire because of
faulty circuit boards or shorting. Let’s not blame the battery
if something else caused the fire.
Why do lawyers require aeromodelers but not the public
to charge batteries in a safe box? The answers are simple.
Members of the public who use a Lithium-powered
product are required, by virtue of its design, to use the
correct (supplied) charger. It is programmed to the correct
charge rate and calibrated to the proper milliamperage/
voltage and proper cell configuration for the particular
battery. This might not be the case with modelers and
their products.
Those in the public realm who use cell phones do not
charge them with a Great Planes Triton or other high-quality
adjustable charger. Grandma Jones can’t dial in the wrong
voltage/amperage, select the wrong battery chemistry, or use
the wrong number of battery cells or incompatible wiring
configurations. By contrast, modelers have the ability to
vary charging and usage parameters that can cause fires.
A lack of operational knowledge makes any mechanical
or electrical item more hazardous for an individual to
operate. The good news is that safety issues can be
addressed through education, so that the operators can avoid
conditions that result in unfortunate incidents.
Following are the major operational issues with
aeromodelers’ Lithium batteries.
• Compatibility: Not all Lithium chargers are compatible
with all brands of Lithium batteries. If you have doubts
about your charger, check the instructions or call the charger
manufacturer before plugging the unit into your battery.
• Dumb or Smart Chargers: If you use a dumb Lithium
charger to charge a dumb Lithium battery, it will catch fire;
02sig2_00MSTRPG.QXD 12/20/10 11:27 AM Page 42
February 2011 43
This 7.4-volt Li-ion battery with two
cells wired in series should be charged
as a two-cell pack at rate of 1C or less.
This is a 7.4-volt Li-ion battery with four
cells. Two series-wired groups are
connected in parallel, to double the
output capacity. It should still be charged
at the 7.4-volt level.
don’t blame the battery. A “dumb”
charger has no ability to regulate the
charge rate. A “dumb” battery has no
smart circuitry onboard to regulate the
incoming charge rate.
Ni-Cd is a dumb battery. Some
Lithium batteries are dumb and some
are smart.
If the battery has an integrated
circuit, it is “smart.” The chip regulates
the charge rate to properly charge the
battery and includes a circuit breaker.
Smart batteries have fallen into
disfavor with many modelers who fly
large aircraft. Imagine performing a
high-G Snap Roll or Blender and
having the circuit breaker blow; down
goes a $6,000 airplane.
If a charger allows a modeler to
select the number of cells, voltage and
current rates, battery chemistry, time,
or cutoff voltage, it is “smart.”
• Wiring configuration: How is your
battery wired? Not all Lithium types
are wired the same. Some are wired in
series and some are wired in series and
parallel. You must know what
configuration you have to safely charge
your batteries, or a fire could result.
Four-cell Lithiums wired in series
parallel are charged as a two-cell on the
7.4-volt setting. If you charge a fourcell,
7.4-volt series parallel pack on the
four-cell (14.8 volt) setting, you will
start a fire.
This is an operator issue—not a
battery issue. Those who are less
experienced in series and parallel
electrical-wiring configuration should
familiarize themselves with basic
electrical data, to get it right the first
time.
Make sure you know and
understand what you are charging
before you make the connections.
Don’t try it to see if it works.
• Current settings: I take regular calls
from aeromodelers who use high-end
programmable chargers, who think that
they have defective Lithium batteries.
Although a new product can be
defective, it is more likely that that
buyer has used the wrong charge
procedure, rates, voltage, or
amperage, or the Ni-Cd setting
instead of Lithium.
Among other mistakes, it is
common to enter the wrong decimal
rate when setting the adjustable
charge rate on a high-end unit.
Instead of dialing in a .5-amp (500
mAh) charge rate, a user might
program 5.0 amps (5000 mAh).
If that is done, the battery could
blow up like a balloon or catch fire a
few minutes into the charge cycle,
and the operator might think that the
battery is defective. A lucky modeler
catches the fire before it burns the
house down. An unlucky modeler’s
house is destroyed.
This is an operator issue. Make
sure that you correctly program the
many variables on a unit.
• High Charge Rates: Heat is the
enemy of all batteries. Many Lithium
units are rated for a 1C (capacity)
charge rate; a 2000 mAh pack 1C
charge rate is 2000 mAh (2 amps). A
Li-ion battery charged at 2000 mAh
will get warm or hot.
Why cook your battery? Do you
fast-charge your cell phone?
A slower charge rate is batteryfriendly,
because it does not generate
the heat that faster charge rates do.
Excess heat makes all battery types
less reliable, shortens their lifespans,
and makes them more prone to
malfunctions caused by internal
changes that occur when they are
charged at high rates.
Li-Poly batteries seldom get
warm if charged at 1C unless there
is a problem. Should that happen,
take the hint and discontinue using
that pack.
My 40% airplanes have 5200 mAh
Li-ion Fromeco packs wired series and
parallel. I charge them at 1 amp. It
takes two to three hours instead of 60
minutes to charge a pack, but if a
flying session ends at 7 p.m., what’s
the point of using a fast charge rate and
cooking the batteries if I’m not going
to go out again until the next day?
Charged and used correctly, I
typically get roughly three years of use
(approximately 1,200 flights) from my
packs. Those who cook their batteries
by fast-charging might blow through
them in a few months or a few charge
cycles and believe that they have a
defective product.
Using multichargers with multiple
chemistry settings and putting a dial on
the wrong chemistry type are common
mistakes that create problems. Make
Operational
Experience
Don’s Hobby Shop has sold and
equipped its own giant-scale models
with Lithium batteries since 1996.
Between then and now I have observed
that danger comes not from using Liion
batteries, but from misusing Lithium
batteries and chargers.
Major mistakes include:
• Using incompatible chargers.
• Setting incorrect charge rates.
• Employing “dumb” chargers with
“dumb” batteries.
• Selecting the wrong settings on
adjustable “smart” chargers.
• Exceeding the current-draw discharge
capacity of a battery.
• Fast-charging batteries faster than the
rated capacity.
• Causing vibration damage by
improperly restraining batteries.
• Subjecting equipment to shock impact
(crashes).
The result of the preceding errors is
often a fire, which many times is a
symptom of aproblem rather than the
problem. A battery might be labeled as
defective, while the true cause of the
mishap often goes unidentified.
I have seen numerous examples of
misuse throughout the 20 years my
store has been in business. The issues
are not new, nor are they limited to
Lithium battery technology. MA
—Don Apostolico
02sig2_00MSTRPG.QXD 12/20/10 11:29 AM Page 43
sure you understand the programming
procedure of your charger before you
connect it.
Using a Ni-Cd or NiMH “dumb” wall
charger or other mismatched charger on a
Lithium battery is a gross mistake, and
there are others. If you exceed the
discharge rate limits of a pack, you will
probably experience venting or a fire.
Purchase a pack that is capable of
delivering the current requirements for
your model.
44 MODEL AVIATION
This fire issue is analogous to burning up a
new digital servo on throttle and then blaming
it for being faulty, when it was the operator
who programmed the servo travel to overdrive
the throttle stops. Then the uninformed
recommend that digital servos not be used on
throttle, because they burn up.
I recommend the opposite. Purchase
digital servos and set them up correctly
(with a current meter) so that they don’t
burn out!
Having flown with and sold Lithium
batteries since 1996 and learning that
handling, storing, and charging any battery
incorrectly can lead to problems, I
recommend exercising caution when
charging or using all batteries.
Be careful when doing your homework;
there is a lot of bad information out there.
Don’t confuse excellent pilot skills with
technical expertise.
Just because your well-meaning friend
can torque roll or says it’s true doesn’t
make it right. You, as the operator, must
take the responsibility to get it right.
Have fun and fly safely. MA
Don Apostolico
[email protected]
Sources:
Don’s Hobby Shop
(800) 972-6273
www.donshobbyshop.com
Fromeco Scale Avionics
(503) 715-0020
www.fromeco.org
Great Planes
(217) 398-8970
www.greatplanes.com
Batteries that are improperly secured
and shift position in an airplane can
contact the plywood formers or a shard of
CA or epoxy glue, which can puncture the
cell; that shorts or vents the battery.
Sometimes batteries are hard-mounted
without foam, and the same damage
occurs. These are operator-setup issues.
A battery that has received impact
damage should never be reused. Internal
damage can cause it to short and cause a
fire. The short might not occur
immediately; you might get several flights
and charge cycles before the final failure
occurs, and then another house or aircraft
is lost.
Experience with tens of thousands of
customers at Don’s Hobby Shop
throughout the years, helping modelers
buy equipment or troubleshoot, has shown
that the overwhelming majority of these
venting problems and fires are caused by
the operator—not the battery.
02sig2_00MSTRPG.QXD 12/20/10 11:30 AM Page 44
Edition: Model Aviation - 2011/02
Page Numbers: 41,42,43,44
February 2011 41
by Don Apostolico
Myths
and facts
popular
power option
about a
This arTiCle will address misinformation and
issues relative to the concerns that many aeromodelers have
regarding the operation of Lithium-ion (Li-ion) and Li-Poly
batteries and the practices that modelers use that cause
batteries to prematurely fail, self-combust, or vent (swell up
like a balloon).
Let’s think about the hundreds of millions of people
around the world who are, at this moment, safely operating
Lithium-powered consumer electronics products without
issue. These items include, but are not limited to, cell
phones, MP3 players, iPods, laptop computers, some
Dremel tools, some GPS systems, numerous garden power
tools, Sears battery-powered drills, hearing aids, digital
cameras, and camcorders.
Contrast that mental image with the modeling
community, which is required to charge Lithium batteries in
ammunition or ceramic safety boxes—in case the batteries
blow up or vent while charging—to prevent houses from
burning down.
Why can Grandma Jones, who doesn’t know a volt from
an amp, charge a consumer-product 5000 mA Lithium
battery on the coffee table in the living room, but John Q.
Modeler has to put the battery in a fortified enclosure? The
reasons will become clear as you continue to read.
The current aeromodeling mind-set regarding the danger
of Lithium batteries has been created by no information,
misinformation, product misuse, uninformed opinions,
reporting the symptom rather than diagnosing the
problem, and blaming the battery rather than identifying
the cause.
Blaming the battery has resulted in the impression that
it causes most incidents or accidents. How many cell
phones, digital cameras, or Dremel tools have you heard
about that have blown up and burned down houses? To
make matters worse, inaccurate stories have been passed
around so many times that, for some, symptoms have
become the cause, and fiction has become fact.
I am not claiming that incidents don’t occur; I’m
informing you that Lithium is one of many power sources
that can combust or vent if operated incorrectly. Improper
charging and handling, random failures, and lack of
understanding of batteries often results in mishaps.
Monitoring and caution are the prudent courses of action
for all batteries—not only Li-ion or Li-Poly.
Consumers’ Vs. Modelers’ Charging Requirements: As
far as I’ve seen, aeromodelers are the only consumers
lawyers require to charge batteries in a safety container,
located outside of the aircraft. That practice is not wrong,
but general consumer-product lawyers do not require the
same charging procedures for other goods that use
Lithium batteries.
Above: Judy Apostolico holds the author’s scratch-built, 30%-scale, 48-pound Cessna 310R. It features a JR radio and servos, two JR
receivers, sequencing gear doors, rivets, panel lines, full interior, twin Lithium batteries, and regulators. Don has used Li-ion batteries
in all of his giant-scale models since 1996.
Li t h i u m
B a t t er i es
L i iu att 02sig2_00MSTRPG.QXD 12/20/10 10:35 AM Page 41
42 MODEL AVIATION
Photos by the author
The high-quality Hobbico Accu-Cycle Elite is capable of
charging a variety of batteries. Many battery failures occur
when users select the wrong charge type for a given battery.
The ElectriFly Triton from Great Planes is a quality unit that can
charge numerous types of batteries. However, it does not have a
balance board bus.
The three-output Fromeco Ion Cube is a DC-input, plug-andplay
unit that accommodates only Li-ion and LiFe batteries.
It’s safe and handy to use to charge giant-scale models with
multiple packs.
You must use correctly programmed, compatible chargers
for the specific battery size, milliamp, cell, and wiring
configuration. Do not leave batteries unattended while charging,
and remember that a slower charge rate is battery-friendly
compared to fast-charging.
Practicing these simple procedures for all types of batteries
will reduce the likelihood of an accident. The user is always
responsible for determining whether or not information
presented is applicable to a particular set of circumstances.
If batteries are handled safely, charged properly, and used
correctly, mishaps can be reduced to those statistically
insignificant random failures that any electronic component
experiences from time to time. MA
—Don Apostolico
Caution!
Some consumer products use more current flow than our
giant models do. However, the general consumer industry
rarely sees cases of Lithium-powered products exploding
and catching fire, resulting in damaged homes. The basic
difference is in the way the public uses and charges batteries
compared to how modelers use and charge their batteries.
Some readers might be able to cite an exception. My Ni-
Cd-powered transmitter was destroyed when it caught fire
while sitting on the workbench with the switch in the off
position. And a customer’s NiMH battery self-combusted on
the counter by the cash register.
A battery with any chemistry can catch fire because of
faulty circuit boards or shorting. Let’s not blame the battery
if something else caused the fire.
Why do lawyers require aeromodelers but not the public
to charge batteries in a safe box? The answers are simple.
Members of the public who use a Lithium-powered
product are required, by virtue of its design, to use the
correct (supplied) charger. It is programmed to the correct
charge rate and calibrated to the proper milliamperage/
voltage and proper cell configuration for the particular
battery. This might not be the case with modelers and
their products.
Those in the public realm who use cell phones do not
charge them with a Great Planes Triton or other high-quality
adjustable charger. Grandma Jones can’t dial in the wrong
voltage/amperage, select the wrong battery chemistry, or use
the wrong number of battery cells or incompatible wiring
configurations. By contrast, modelers have the ability to
vary charging and usage parameters that can cause fires.
A lack of operational knowledge makes any mechanical
or electrical item more hazardous for an individual to
operate. The good news is that safety issues can be
addressed through education, so that the operators can avoid
conditions that result in unfortunate incidents.
Following are the major operational issues with
aeromodelers’ Lithium batteries.
• Compatibility: Not all Lithium chargers are compatible
with all brands of Lithium batteries. If you have doubts
about your charger, check the instructions or call the charger
manufacturer before plugging the unit into your battery.
• Dumb or Smart Chargers: If you use a dumb Lithium
charger to charge a dumb Lithium battery, it will catch fire;
02sig2_00MSTRPG.QXD 12/20/10 11:27 AM Page 42
February 2011 43
This 7.4-volt Li-ion battery with two
cells wired in series should be charged
as a two-cell pack at rate of 1C or less.
This is a 7.4-volt Li-ion battery with four
cells. Two series-wired groups are
connected in parallel, to double the
output capacity. It should still be charged
at the 7.4-volt level.
don’t blame the battery. A “dumb”
charger has no ability to regulate the
charge rate. A “dumb” battery has no
smart circuitry onboard to regulate the
incoming charge rate.
Ni-Cd is a dumb battery. Some
Lithium batteries are dumb and some
are smart.
If the battery has an integrated
circuit, it is “smart.” The chip regulates
the charge rate to properly charge the
battery and includes a circuit breaker.
Smart batteries have fallen into
disfavor with many modelers who fly
large aircraft. Imagine performing a
high-G Snap Roll or Blender and
having the circuit breaker blow; down
goes a $6,000 airplane.
If a charger allows a modeler to
select the number of cells, voltage and
current rates, battery chemistry, time,
or cutoff voltage, it is “smart.”
• Wiring configuration: How is your
battery wired? Not all Lithium types
are wired the same. Some are wired in
series and some are wired in series and
parallel. You must know what
configuration you have to safely charge
your batteries, or a fire could result.
Four-cell Lithiums wired in series
parallel are charged as a two-cell on the
7.4-volt setting. If you charge a fourcell,
7.4-volt series parallel pack on the
four-cell (14.8 volt) setting, you will
start a fire.
This is an operator issue—not a
battery issue. Those who are less
experienced in series and parallel
electrical-wiring configuration should
familiarize themselves with basic
electrical data, to get it right the first
time.
Make sure you know and
understand what you are charging
before you make the connections.
Don’t try it to see if it works.
• Current settings: I take regular calls
from aeromodelers who use high-end
programmable chargers, who think that
they have defective Lithium batteries.
Although a new product can be
defective, it is more likely that that
buyer has used the wrong charge
procedure, rates, voltage, or
amperage, or the Ni-Cd setting
instead of Lithium.
Among other mistakes, it is
common to enter the wrong decimal
rate when setting the adjustable
charge rate on a high-end unit.
Instead of dialing in a .5-amp (500
mAh) charge rate, a user might
program 5.0 amps (5000 mAh).
If that is done, the battery could
blow up like a balloon or catch fire a
few minutes into the charge cycle,
and the operator might think that the
battery is defective. A lucky modeler
catches the fire before it burns the
house down. An unlucky modeler’s
house is destroyed.
This is an operator issue. Make
sure that you correctly program the
many variables on a unit.
• High Charge Rates: Heat is the
enemy of all batteries. Many Lithium
units are rated for a 1C (capacity)
charge rate; a 2000 mAh pack 1C
charge rate is 2000 mAh (2 amps). A
Li-ion battery charged at 2000 mAh
will get warm or hot.
Why cook your battery? Do you
fast-charge your cell phone?
A slower charge rate is batteryfriendly,
because it does not generate
the heat that faster charge rates do.
Excess heat makes all battery types
less reliable, shortens their lifespans,
and makes them more prone to
malfunctions caused by internal
changes that occur when they are
charged at high rates.
Li-Poly batteries seldom get
warm if charged at 1C unless there
is a problem. Should that happen,
take the hint and discontinue using
that pack.
My 40% airplanes have 5200 mAh
Li-ion Fromeco packs wired series and
parallel. I charge them at 1 amp. It
takes two to three hours instead of 60
minutes to charge a pack, but if a
flying session ends at 7 p.m., what’s
the point of using a fast charge rate and
cooking the batteries if I’m not going
to go out again until the next day?
Charged and used correctly, I
typically get roughly three years of use
(approximately 1,200 flights) from my
packs. Those who cook their batteries
by fast-charging might blow through
them in a few months or a few charge
cycles and believe that they have a
defective product.
Using multichargers with multiple
chemistry settings and putting a dial on
the wrong chemistry type are common
mistakes that create problems. Make
Operational
Experience
Don’s Hobby Shop has sold and
equipped its own giant-scale models
with Lithium batteries since 1996.
Between then and now I have observed
that danger comes not from using Liion
batteries, but from misusing Lithium
batteries and chargers.
Major mistakes include:
• Using incompatible chargers.
• Setting incorrect charge rates.
• Employing “dumb” chargers with
“dumb” batteries.
• Selecting the wrong settings on
adjustable “smart” chargers.
• Exceeding the current-draw discharge
capacity of a battery.
• Fast-charging batteries faster than the
rated capacity.
• Causing vibration damage by
improperly restraining batteries.
• Subjecting equipment to shock impact
(crashes).
The result of the preceding errors is
often a fire, which many times is a
symptom of aproblem rather than the
problem. A battery might be labeled as
defective, while the true cause of the
mishap often goes unidentified.
I have seen numerous examples of
misuse throughout the 20 years my
store has been in business. The issues
are not new, nor are they limited to
Lithium battery technology. MA
—Don Apostolico
02sig2_00MSTRPG.QXD 12/20/10 11:29 AM Page 43
sure you understand the programming
procedure of your charger before you
connect it.
Using a Ni-Cd or NiMH “dumb” wall
charger or other mismatched charger on a
Lithium battery is a gross mistake, and
there are others. If you exceed the
discharge rate limits of a pack, you will
probably experience venting or a fire.
Purchase a pack that is capable of
delivering the current requirements for
your model.
44 MODEL AVIATION
This fire issue is analogous to burning up a
new digital servo on throttle and then blaming
it for being faulty, when it was the operator
who programmed the servo travel to overdrive
the throttle stops. Then the uninformed
recommend that digital servos not be used on
throttle, because they burn up.
I recommend the opposite. Purchase
digital servos and set them up correctly
(with a current meter) so that they don’t
burn out!
Having flown with and sold Lithium
batteries since 1996 and learning that
handling, storing, and charging any battery
incorrectly can lead to problems, I
recommend exercising caution when
charging or using all batteries.
Be careful when doing your homework;
there is a lot of bad information out there.
Don’t confuse excellent pilot skills with
technical expertise.
Just because your well-meaning friend
can torque roll or says it’s true doesn’t
make it right. You, as the operator, must
take the responsibility to get it right.
Have fun and fly safely. MA
Don Apostolico
[email protected]
Sources:
Don’s Hobby Shop
(800) 972-6273
www.donshobbyshop.com
Fromeco Scale Avionics
(503) 715-0020
www.fromeco.org
Great Planes
(217) 398-8970
www.greatplanes.com
Batteries that are improperly secured
and shift position in an airplane can
contact the plywood formers or a shard of
CA or epoxy glue, which can puncture the
cell; that shorts or vents the battery.
Sometimes batteries are hard-mounted
without foam, and the same damage
occurs. These are operator-setup issues.
A battery that has received impact
damage should never be reused. Internal
damage can cause it to short and cause a
fire. The short might not occur
immediately; you might get several flights
and charge cycles before the final failure
occurs, and then another house or aircraft
is lost.
Experience with tens of thousands of
customers at Don’s Hobby Shop
throughout the years, helping modelers
buy equipment or troubleshoot, has shown
that the overwhelming majority of these
venting problems and fires are caused by
the operator—not the battery.
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