November 2009 103
Red Scholefield | redscho@The Battery Clinic bellsouth.net
Also included in this column:
• Parallel operation of Li-Polys
• A123 update
• Triton EQ chargers
• Dave Platt goes electric
Electric aeromodeling history
Above: A Li-Poly cell interconnection PC
board.
Right: The author’s LiFePO4 (A123)
discharge comparison after three years of
usage.
An early 1960s electric model with homemade battery, shown in the inset.
FOLLOWING IS A post by Simon Chaddock
that I picked up on one of the modeling forums.
“I cannot claim to have matched the electric
achievements of Col. Taplin but I did make a
very light electric flyer in the early 1960s. Not
RC but it did fly—just. 40 inch span it weighed
just 2.5 ounces complete! Apart from its ever so
delicate light weight construction the clever bit
was the miniature bichromate battery, made by
my dad.
“Not really a safe plane battery as it used
Sulphuric acid as the electrolyte and potassium
bichromate (a deep purple dye) as the
depolarizer! It was however capable of
producing a good burst of current (for a short
time) so much so that the electrolyte could boil.
“In fact my Dad made two batteries. The
second battery (inset) was same size (1 inch x 1
inch x 1.25 inches) and weight (1oz) as the first
but more powerful as it had 5 thinner plates per
cell instead of 3. It could deliver 6 amps at 2
volts for 10 seconds or 1 amp at 3 volts for a
minute.
“It’s so much easier to fly electric now!”
This begs the question, Who is or was Col.
Taplin?
Reader Inquiries: Gary Ritchie of Olympia,
Washington, wrote:
“Here is a question I’d like to see you
address in a future column. Let’s say you
have a 5s LiPo pack and one cell goes bad.
How can you safely disassemble the pack and
rebuild it as a viable 4s pack?”
Technically, it can be done—if one is
proficient at desoldering. The problem is
trying to release the tabs from the cells that
are usually interconnected by a small PC
board. These tabs are fragile and can be easily
damaged if subjected to stress.
You will need some way to remove the
solder. This is usually done with a tool called
a “solder sucker” or, more properly, Vacuum
Desoldering Tool, which is available in most
electronic supply houses, such as RadioShack.
These cost less than $10 and are a must if you
do much soldering work on PC boards.
Heat Kills: Eric Richardson wrote:
“Having moved to Ft. Worth, TX from the
upper Midwest it’s my practice to store my
aircraft in the garage on trickle charge.
“Recently while pre-flighting I noticed one
of my battery packs was below flight
voltage—so packed up and went home. I
cycled all flight packs on my Triton and each
failed to hold a charge.
“Question: what is the common practice or
suggestion for storing batteries in hot
climates? I’m guessing the high temperatures
Fig3
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 103
in the garage accelerated battery life as they were only 3 years old.”
Storing on trickle charge in a hot environment will accelerate
separator deterioration, meaning that your packs will develop internal
shorts. Don’t store on trickle charge and don’t store in a hot place. I
remove my packs and store them in the refrigerator (40°) until I need
them.
Battery life is cut in half for every 17° above room temperature
(68°). So if you are storing at 90°, you are cutting the life; mean time
between failure is approximately seven years. You will be down to less
than half of that when you start seeing your packs fail.
Parallel Li-Poly Operation: There has been much discussion about
this on some RC forums—and almost the same amount of
misinformation, particularly about charging. Li-Poly packs can be
charged and discharged safely in parallel, as long as each pack has the
same number of cells.
One caveat is that charging packs in parallel is a problem if you
want to balance at the same time. Don’t
attempt it!
Although I strongly recommend
balancing, and I do it on every charge, it’s
unnecessary on every charge. So if you want
to bring up a couple of packs by charging
them through the power lead at the field, you
can feel reasonably confident that you will not
harm your packs. But make sure to balance
them when you return to the shop.
I never recommend charging Ni-Cd or
NiMH in parallel. Discharging is okay and is
a good way to increase capacity if you need it.
Lithium packs are essentially constantvoltage-
charge systems. You charge them to a
fixed level (4.2 volts per cell). Ni-Cd and
NiMH packs can be damaged unless the
charge is controlled and set to terminate based
on a voltage-peak profile.
No Ni-Cd or NiMH packs are identical.
One might peak before the other when in
parallel. The one that peaks first starts
declining in voltage, and the charger will try
to increase current to that pack and limit
current to the other. This situation can cause
thermal runaway if the charger has enough
current capacity.
LiFePO4 (A123) Update: Three years ago, I
built and installed my A123 packs made from
36-volt DeWalt packs. I am running them in
4S2P and 4S1P configurations and flying
year-round here in Florida.
These packs have nearly 200 charges and
are still giving good-capacity discharges, as
you can see in one of the photos, where early
discharge 7/06 is compared to one today—
7/09. I do balance on each charge—not that I
think they need it on every charge, but the
FMA Direct Cellpro 10s does it anyway.
There is an excellent discussion by Ken
Myers on his Electric Flyers Only Web site,
covering LiFePO4 technology. Look for the
address in the source list at the end of this
column.
Is Your Glider-Launching Arm Getting
Weak? I was getting along fine launching my
2-meter sailplanes until a flying buddy, Andy
Druga, fell in love with the Bird of Time. I
was uncomfortable hand-launching this
beauty, since Andy’s skills in recovering from
a bad launch matched the probability that I
would not mess it up.
104 MODEL AVIATION
Great Planes’ ElectriFly Triton 2 EQ charger cycle plot showing
protocol.
Andy Druga’s Bird of Time goes electric. The model’s launcher is detailed in an inset.
Dave Platt, who is a master builder, with his first electric-powered model: the twinmotor
TWOCAN that he designed.
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 104
Remembering the dark past of CL Speed
models, I came up with a launch dolly. The
Bird lifted off after roughly a 10-foot roll. Since
then, we have successfully launched 2-meter
Speed 400-powered gliders as well.
My design takes all of the guesswork out.
Set your glider on the dolly and head it into the
wind. I found that you can even control it with
rudder if correction is needed. We have had
many suggestions about how we could
motorize the dolly and bring it back to the pit
area instead of having someone retrieve it.
Construction involves 14 pieces of 1/2-inchdiameter
PVC pipe: six 8-inch pieces, four 10-
inch pieces, two 4-inch pieces, and two 2-inch
pieces. You will also need six Ts, two elbows,
two end caps, and PVC cement.
Make sure that all joints are straight. Give
some thought to the assembly process, so you
can take advantage of laying the parts flat as
you put them together.
The verticals with the Ts added first are the
last part to use in joining the front to the rear of
the dolly. Add 4-inch wheels, and you are
ready to launch.
Triton EQ Chargers: You can review
chargers when you receive them, checking to
make sure that they meet all stated performance
numbers. I reported that in September’s “The
Battery Clinic” column.
Now that I have had the Tritons working on
my charging bench for several months, serving
a number of my charging requirements, I am
happy to report that performance has been
flawless.
One thing that has bothered some users is
that the charge currents might not be what you
select. The chargers are limited in the amount
of power they can produce in charging;
therefore, if you are charging packs with a
higher cell count, you cannot charge them at
the maximum stated current rating. Discharge
currents are power-limited too.
The Triton 2 EQ is limited to 100 watts
charging and 20 watts discharging. The Triton
EQ is somewhat reduced, with the maximum
charge power set at 63 watts in DC mode and
50 watts maximum for the AC power mode.
Discharge is limited to 5 watts maximum.
The Triton 2 EQ manual covers this nicely
on page 19, while the Triton EQ manual avoids
pointing it out other than in the specifications.
This means that while the Triton 2 EQ
states an 8-amp charge capability, you can use
only 8 amps on packs with a voltage that is no
more than 12 volts. With anything higher than
that, the 100-watt power limit kicks in. The
same is true for the Triton EQ. There is nothing
wrong with your charger; just read the
instructions.
The Triton 2 EQ and EQ follow the
accepted peak-charge procedure, monitoring
the voltage during the charge and then sensing
when it peaks. A discharge/charge cycle is
shown.
Notice that as the peak is reached, the
charge current is pulsed, so sensing is between
the open-circuit voltage and the charge voltage,
which gives a much more accurate termination
than simply monitoring the voltage while on
charge.
The curves were plotted using an
inexpensive recording digital voltmeter with an
RS232 connection to my shop computer. These
come in handy if you are doing battery
investigations and your charger/discharger does
not have a computer interface.
Dave Platt’s First Electric: I had the
opportunity to visit the prestigious RCACF
(Radio Control Association of Central Florida),
for its July 4 electric fly-in. It was well
attended, considering the temperatures
exceeded 95°.
Dave Platt, a master modeler, was there
with what he claimed was his first venture into
electric-powered flight. His original-design
TWOCAN, a sleek, twin-motor model,
featured contrarotating propellers, a military
theme, and retracts. It featured crisp
performance.
Have a nice building season, you lucky dogs.
We miss them here in Florida. MA
Sources:
The Battery Clinic
12219 NW 9th Ln.
Newberry FL 32669
www.hangtimes.com/redsbatteryclinic.html
Electric Flyers Only
http://homepage.mac.com/kmyersefo
RCACF
www.rcacf.com
Edition: Model Aviation - 2009/11
Page Numbers: 103,104,106
Edition: Model Aviation - 2009/11
Page Numbers: 103,104,106
November 2009 103
Red Scholefield | redscho@The Battery Clinic bellsouth.net
Also included in this column:
• Parallel operation of Li-Polys
• A123 update
• Triton EQ chargers
• Dave Platt goes electric
Electric aeromodeling history
Above: A Li-Poly cell interconnection PC
board.
Right: The author’s LiFePO4 (A123)
discharge comparison after three years of
usage.
An early 1960s electric model with homemade battery, shown in the inset.
FOLLOWING IS A post by Simon Chaddock
that I picked up on one of the modeling forums.
“I cannot claim to have matched the electric
achievements of Col. Taplin but I did make a
very light electric flyer in the early 1960s. Not
RC but it did fly—just. 40 inch span it weighed
just 2.5 ounces complete! Apart from its ever so
delicate light weight construction the clever bit
was the miniature bichromate battery, made by
my dad.
“Not really a safe plane battery as it used
Sulphuric acid as the electrolyte and potassium
bichromate (a deep purple dye) as the
depolarizer! It was however capable of
producing a good burst of current (for a short
time) so much so that the electrolyte could boil.
“In fact my Dad made two batteries. The
second battery (inset) was same size (1 inch x 1
inch x 1.25 inches) and weight (1oz) as the first
but more powerful as it had 5 thinner plates per
cell instead of 3. It could deliver 6 amps at 2
volts for 10 seconds or 1 amp at 3 volts for a
minute.
“It’s so much easier to fly electric now!”
This begs the question, Who is or was Col.
Taplin?
Reader Inquiries: Gary Ritchie of Olympia,
Washington, wrote:
“Here is a question I’d like to see you
address in a future column. Let’s say you
have a 5s LiPo pack and one cell goes bad.
How can you safely disassemble the pack and
rebuild it as a viable 4s pack?”
Technically, it can be done—if one is
proficient at desoldering. The problem is
trying to release the tabs from the cells that
are usually interconnected by a small PC
board. These tabs are fragile and can be easily
damaged if subjected to stress.
You will need some way to remove the
solder. This is usually done with a tool called
a “solder sucker” or, more properly, Vacuum
Desoldering Tool, which is available in most
electronic supply houses, such as RadioShack.
These cost less than $10 and are a must if you
do much soldering work on PC boards.
Heat Kills: Eric Richardson wrote:
“Having moved to Ft. Worth, TX from the
upper Midwest it’s my practice to store my
aircraft in the garage on trickle charge.
“Recently while pre-flighting I noticed one
of my battery packs was below flight
voltage—so packed up and went home. I
cycled all flight packs on my Triton and each
failed to hold a charge.
“Question: what is the common practice or
suggestion for storing batteries in hot
climates? I’m guessing the high temperatures
Fig3
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 103
in the garage accelerated battery life as they were only 3 years old.”
Storing on trickle charge in a hot environment will accelerate
separator deterioration, meaning that your packs will develop internal
shorts. Don’t store on trickle charge and don’t store in a hot place. I
remove my packs and store them in the refrigerator (40°) until I need
them.
Battery life is cut in half for every 17° above room temperature
(68°). So if you are storing at 90°, you are cutting the life; mean time
between failure is approximately seven years. You will be down to less
than half of that when you start seeing your packs fail.
Parallel Li-Poly Operation: There has been much discussion about
this on some RC forums—and almost the same amount of
misinformation, particularly about charging. Li-Poly packs can be
charged and discharged safely in parallel, as long as each pack has the
same number of cells.
One caveat is that charging packs in parallel is a problem if you
want to balance at the same time. Don’t
attempt it!
Although I strongly recommend
balancing, and I do it on every charge, it’s
unnecessary on every charge. So if you want
to bring up a couple of packs by charging
them through the power lead at the field, you
can feel reasonably confident that you will not
harm your packs. But make sure to balance
them when you return to the shop.
I never recommend charging Ni-Cd or
NiMH in parallel. Discharging is okay and is
a good way to increase capacity if you need it.
Lithium packs are essentially constantvoltage-
charge systems. You charge them to a
fixed level (4.2 volts per cell). Ni-Cd and
NiMH packs can be damaged unless the
charge is controlled and set to terminate based
on a voltage-peak profile.
No Ni-Cd or NiMH packs are identical.
One might peak before the other when in
parallel. The one that peaks first starts
declining in voltage, and the charger will try
to increase current to that pack and limit
current to the other. This situation can cause
thermal runaway if the charger has enough
current capacity.
LiFePO4 (A123) Update: Three years ago, I
built and installed my A123 packs made from
36-volt DeWalt packs. I am running them in
4S2P and 4S1P configurations and flying
year-round here in Florida.
These packs have nearly 200 charges and
are still giving good-capacity discharges, as
you can see in one of the photos, where early
discharge 7/06 is compared to one today—
7/09. I do balance on each charge—not that I
think they need it on every charge, but the
FMA Direct Cellpro 10s does it anyway.
There is an excellent discussion by Ken
Myers on his Electric Flyers Only Web site,
covering LiFePO4 technology. Look for the
address in the source list at the end of this
column.
Is Your Glider-Launching Arm Getting
Weak? I was getting along fine launching my
2-meter sailplanes until a flying buddy, Andy
Druga, fell in love with the Bird of Time. I
was uncomfortable hand-launching this
beauty, since Andy’s skills in recovering from
a bad launch matched the probability that I
would not mess it up.
104 MODEL AVIATION
Great Planes’ ElectriFly Triton 2 EQ charger cycle plot showing
protocol.
Andy Druga’s Bird of Time goes electric. The model’s launcher is detailed in an inset.
Dave Platt, who is a master builder, with his first electric-powered model: the twinmotor
TWOCAN that he designed.
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 104
Remembering the dark past of CL Speed
models, I came up with a launch dolly. The
Bird lifted off after roughly a 10-foot roll. Since
then, we have successfully launched 2-meter
Speed 400-powered gliders as well.
My design takes all of the guesswork out.
Set your glider on the dolly and head it into the
wind. I found that you can even control it with
rudder if correction is needed. We have had
many suggestions about how we could
motorize the dolly and bring it back to the pit
area instead of having someone retrieve it.
Construction involves 14 pieces of 1/2-inchdiameter
PVC pipe: six 8-inch pieces, four 10-
inch pieces, two 4-inch pieces, and two 2-inch
pieces. You will also need six Ts, two elbows,
two end caps, and PVC cement.
Make sure that all joints are straight. Give
some thought to the assembly process, so you
can take advantage of laying the parts flat as
you put them together.
The verticals with the Ts added first are the
last part to use in joining the front to the rear of
the dolly. Add 4-inch wheels, and you are
ready to launch.
Triton EQ Chargers: You can review
chargers when you receive them, checking to
make sure that they meet all stated performance
numbers. I reported that in September’s “The
Battery Clinic” column.
Now that I have had the Tritons working on
my charging bench for several months, serving
a number of my charging requirements, I am
happy to report that performance has been
flawless.
One thing that has bothered some users is
that the charge currents might not be what you
select. The chargers are limited in the amount
of power they can produce in charging;
therefore, if you are charging packs with a
higher cell count, you cannot charge them at
the maximum stated current rating. Discharge
currents are power-limited too.
The Triton 2 EQ is limited to 100 watts
charging and 20 watts discharging. The Triton
EQ is somewhat reduced, with the maximum
charge power set at 63 watts in DC mode and
50 watts maximum for the AC power mode.
Discharge is limited to 5 watts maximum.
The Triton 2 EQ manual covers this nicely
on page 19, while the Triton EQ manual avoids
pointing it out other than in the specifications.
This means that while the Triton 2 EQ
states an 8-amp charge capability, you can use
only 8 amps on packs with a voltage that is no
more than 12 volts. With anything higher than
that, the 100-watt power limit kicks in. The
same is true for the Triton EQ. There is nothing
wrong with your charger; just read the
instructions.
The Triton 2 EQ and EQ follow the
accepted peak-charge procedure, monitoring
the voltage during the charge and then sensing
when it peaks. A discharge/charge cycle is
shown.
Notice that as the peak is reached, the
charge current is pulsed, so sensing is between
the open-circuit voltage and the charge voltage,
which gives a much more accurate termination
than simply monitoring the voltage while on
charge.
The curves were plotted using an
inexpensive recording digital voltmeter with an
RS232 connection to my shop computer. These
come in handy if you are doing battery
investigations and your charger/discharger does
not have a computer interface.
Dave Platt’s First Electric: I had the
opportunity to visit the prestigious RCACF
(Radio Control Association of Central Florida),
for its July 4 electric fly-in. It was well
attended, considering the temperatures
exceeded 95°.
Dave Platt, a master modeler, was there
with what he claimed was his first venture into
electric-powered flight. His original-design
TWOCAN, a sleek, twin-motor model,
featured contrarotating propellers, a military
theme, and retracts. It featured crisp
performance.
Have a nice building season, you lucky dogs.
We miss them here in Florida. MA
Sources:
The Battery Clinic
12219 NW 9th Ln.
Newberry FL 32669
www.hangtimes.com/redsbatteryclinic.html
Electric Flyers Only
http://homepage.mac.com/kmyersefo
RCACF
www.rcacf.com
Edition: Model Aviation - 2009/11
Page Numbers: 103,104,106
November 2009 103
Red Scholefield | redscho@The Battery Clinic bellsouth.net
Also included in this column:
• Parallel operation of Li-Polys
• A123 update
• Triton EQ chargers
• Dave Platt goes electric
Electric aeromodeling history
Above: A Li-Poly cell interconnection PC
board.
Right: The author’s LiFePO4 (A123)
discharge comparison after three years of
usage.
An early 1960s electric model with homemade battery, shown in the inset.
FOLLOWING IS A post by Simon Chaddock
that I picked up on one of the modeling forums.
“I cannot claim to have matched the electric
achievements of Col. Taplin but I did make a
very light electric flyer in the early 1960s. Not
RC but it did fly—just. 40 inch span it weighed
just 2.5 ounces complete! Apart from its ever so
delicate light weight construction the clever bit
was the miniature bichromate battery, made by
my dad.
“Not really a safe plane battery as it used
Sulphuric acid as the electrolyte and potassium
bichromate (a deep purple dye) as the
depolarizer! It was however capable of
producing a good burst of current (for a short
time) so much so that the electrolyte could boil.
“In fact my Dad made two batteries. The
second battery (inset) was same size (1 inch x 1
inch x 1.25 inches) and weight (1oz) as the first
but more powerful as it had 5 thinner plates per
cell instead of 3. It could deliver 6 amps at 2
volts for 10 seconds or 1 amp at 3 volts for a
minute.
“It’s so much easier to fly electric now!”
This begs the question, Who is or was Col.
Taplin?
Reader Inquiries: Gary Ritchie of Olympia,
Washington, wrote:
“Here is a question I’d like to see you
address in a future column. Let’s say you
have a 5s LiPo pack and one cell goes bad.
How can you safely disassemble the pack and
rebuild it as a viable 4s pack?”
Technically, it can be done—if one is
proficient at desoldering. The problem is
trying to release the tabs from the cells that
are usually interconnected by a small PC
board. These tabs are fragile and can be easily
damaged if subjected to stress.
You will need some way to remove the
solder. This is usually done with a tool called
a “solder sucker” or, more properly, Vacuum
Desoldering Tool, which is available in most
electronic supply houses, such as RadioShack.
These cost less than $10 and are a must if you
do much soldering work on PC boards.
Heat Kills: Eric Richardson wrote:
“Having moved to Ft. Worth, TX from the
upper Midwest it’s my practice to store my
aircraft in the garage on trickle charge.
“Recently while pre-flighting I noticed one
of my battery packs was below flight
voltage—so packed up and went home. I
cycled all flight packs on my Triton and each
failed to hold a charge.
“Question: what is the common practice or
suggestion for storing batteries in hot
climates? I’m guessing the high temperatures
Fig3
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 103
in the garage accelerated battery life as they were only 3 years old.”
Storing on trickle charge in a hot environment will accelerate
separator deterioration, meaning that your packs will develop internal
shorts. Don’t store on trickle charge and don’t store in a hot place. I
remove my packs and store them in the refrigerator (40°) until I need
them.
Battery life is cut in half for every 17° above room temperature
(68°). So if you are storing at 90°, you are cutting the life; mean time
between failure is approximately seven years. You will be down to less
than half of that when you start seeing your packs fail.
Parallel Li-Poly Operation: There has been much discussion about
this on some RC forums—and almost the same amount of
misinformation, particularly about charging. Li-Poly packs can be
charged and discharged safely in parallel, as long as each pack has the
same number of cells.
One caveat is that charging packs in parallel is a problem if you
want to balance at the same time. Don’t
attempt it!
Although I strongly recommend
balancing, and I do it on every charge, it’s
unnecessary on every charge. So if you want
to bring up a couple of packs by charging
them through the power lead at the field, you
can feel reasonably confident that you will not
harm your packs. But make sure to balance
them when you return to the shop.
I never recommend charging Ni-Cd or
NiMH in parallel. Discharging is okay and is
a good way to increase capacity if you need it.
Lithium packs are essentially constantvoltage-
charge systems. You charge them to a
fixed level (4.2 volts per cell). Ni-Cd and
NiMH packs can be damaged unless the
charge is controlled and set to terminate based
on a voltage-peak profile.
No Ni-Cd or NiMH packs are identical.
One might peak before the other when in
parallel. The one that peaks first starts
declining in voltage, and the charger will try
to increase current to that pack and limit
current to the other. This situation can cause
thermal runaway if the charger has enough
current capacity.
LiFePO4 (A123) Update: Three years ago, I
built and installed my A123 packs made from
36-volt DeWalt packs. I am running them in
4S2P and 4S1P configurations and flying
year-round here in Florida.
These packs have nearly 200 charges and
are still giving good-capacity discharges, as
you can see in one of the photos, where early
discharge 7/06 is compared to one today—
7/09. I do balance on each charge—not that I
think they need it on every charge, but the
FMA Direct Cellpro 10s does it anyway.
There is an excellent discussion by Ken
Myers on his Electric Flyers Only Web site,
covering LiFePO4 technology. Look for the
address in the source list at the end of this
column.
Is Your Glider-Launching Arm Getting
Weak? I was getting along fine launching my
2-meter sailplanes until a flying buddy, Andy
Druga, fell in love with the Bird of Time. I
was uncomfortable hand-launching this
beauty, since Andy’s skills in recovering from
a bad launch matched the probability that I
would not mess it up.
104 MODEL AVIATION
Great Planes’ ElectriFly Triton 2 EQ charger cycle plot showing
protocol.
Andy Druga’s Bird of Time goes electric. The model’s launcher is detailed in an inset.
Dave Platt, who is a master builder, with his first electric-powered model: the twinmotor
TWOCAN that he designed.
11sig4.QXD_00MSTRPG.QXD 9/24/09 4:47 PM Page 104
Remembering the dark past of CL Speed
models, I came up with a launch dolly. The
Bird lifted off after roughly a 10-foot roll. Since
then, we have successfully launched 2-meter
Speed 400-powered gliders as well.
My design takes all of the guesswork out.
Set your glider on the dolly and head it into the
wind. I found that you can even control it with
rudder if correction is needed. We have had
many suggestions about how we could
motorize the dolly and bring it back to the pit
area instead of having someone retrieve it.
Construction involves 14 pieces of 1/2-inchdiameter
PVC pipe: six 8-inch pieces, four 10-
inch pieces, two 4-inch pieces, and two 2-inch
pieces. You will also need six Ts, two elbows,
two end caps, and PVC cement.
Make sure that all joints are straight. Give
some thought to the assembly process, so you
can take advantage of laying the parts flat as
you put them together.
The verticals with the Ts added first are the
last part to use in joining the front to the rear of
the dolly. Add 4-inch wheels, and you are
ready to launch.
Triton EQ Chargers: You can review
chargers when you receive them, checking to
make sure that they meet all stated performance
numbers. I reported that in September’s “The
Battery Clinic” column.
Now that I have had the Tritons working on
my charging bench for several months, serving
a number of my charging requirements, I am
happy to report that performance has been
flawless.
One thing that has bothered some users is
that the charge currents might not be what you
select. The chargers are limited in the amount
of power they can produce in charging;
therefore, if you are charging packs with a
higher cell count, you cannot charge them at
the maximum stated current rating. Discharge
currents are power-limited too.
The Triton 2 EQ is limited to 100 watts
charging and 20 watts discharging. The Triton
EQ is somewhat reduced, with the maximum
charge power set at 63 watts in DC mode and
50 watts maximum for the AC power mode.
Discharge is limited to 5 watts maximum.
The Triton 2 EQ manual covers this nicely
on page 19, while the Triton EQ manual avoids
pointing it out other than in the specifications.
This means that while the Triton 2 EQ
states an 8-amp charge capability, you can use
only 8 amps on packs with a voltage that is no
more than 12 volts. With anything higher than
that, the 100-watt power limit kicks in. The
same is true for the Triton EQ. There is nothing
wrong with your charger; just read the
instructions.
The Triton 2 EQ and EQ follow the
accepted peak-charge procedure, monitoring
the voltage during the charge and then sensing
when it peaks. A discharge/charge cycle is
shown.
Notice that as the peak is reached, the
charge current is pulsed, so sensing is between
the open-circuit voltage and the charge voltage,
which gives a much more accurate termination
than simply monitoring the voltage while on
charge.
The curves were plotted using an
inexpensive recording digital voltmeter with an
RS232 connection to my shop computer. These
come in handy if you are doing battery
investigations and your charger/discharger does
not have a computer interface.
Dave Platt’s First Electric: I had the
opportunity to visit the prestigious RCACF
(Radio Control Association of Central Florida),
for its July 4 electric fly-in. It was well
attended, considering the temperatures
exceeded 95°.
Dave Platt, a master modeler, was there
with what he claimed was his first venture into
electric-powered flight. His original-design
TWOCAN, a sleek, twin-motor model,
featured contrarotating propellers, a military
theme, and retracts. It featured crisp
performance.
Have a nice building season, you lucky dogs.
We miss them here in Florida. MA
Sources:
The Battery Clinic
12219 NW 9th Ln.
Newberry FL 32669
www.hangtimes.com/redsbatteryclinic.html
Electric Flyers Only
http://homepage.mac.com/kmyersefo
RCACF
www.rcacf.com
