Safety is YOUR Job!!
Ocean County Modelers,
Inc.
By-Lines & Fly-Lines
P.O. Box 569, Lakehurst, NJ 08733-0569
December 2013
Electric Flight Basics
LIPO Battery Tutorial, Part I
By Doug Lindauer
T
here are 3 basic concepts you should know about LIPO batteries:
1. The mAh capacity (this is a measure of how long the charge will last)
2. The C ratings (these have to do with charging and discharging)
3. The amount of energy stored in the battery. This is different from the mAh capacity.
Amps and Volts
Before we talk about any of these things we need to review basic electrical concepts because
otherwise you’ll never understand these things. If you already know this you can skip over this
section.
Amps: An Amp is a measure of electrical current. It’s like the amount of water flowing in a
pipe. The bigger the wire, the more current can flow, just like the bigger the pipe, the more water can flow. Amperage is computed by measuring amount of electrons that flow by every second. If you really want to get technical, it’s expressed as Coulombs/Second. Coulombs is a
measure of how many electrons there are. One Coulomb is a LOT of electrons! But that’s not
really important here.
Volts: Volts is a measure of electrical pressure. The more volts, the more current you can
push through the wire, just like you can push more water through a pipe when you have greater
water pressure. The “milli” prefix: “milli” means a thousandth part of something. If you have
1,000 milliAmps then it’s the same as saying 1 Amp. One-thousand milliVolts is the same as 1
Volt. One-hundred milliAmps is the same as .1 Amps and so on.
AmpHours or milliAmpHours (mAh)
The mAh rating is stamped on the front of every LIPO. What it means is how many
milliamps you can suck out of the battery for one hour. If you divide the mAh rating by 1000
you would get how many amps you could drain out of it for an hour. For example, to fully discharge a 2000 mAh battery you could draw 2000 milliamps (which is the same as 2 amps) out
See, LIPO , page 2
Ocean County Modelers Inc.
Page 2
Club Officers
PRESIDENT
Louis Capurso
201-376-3512
[email protected]
VICE PRESIDENT
Edward Hollema
201-406-5077
[email protected]
TREASURER
Joseph Acquisto
732-614-2737
[email protected]
CORRESPONDING
SECRETARY
Jam Rabii
732-966-1467
[email protected]
RECORDING SECRETARY
Thomas Moore
732-644-8601
[email protected]
SAFETY OFFICER
Dan Ditursi
732-818-1692
[email protected]
NEWSLETTER EDITOR
Sue Fevola
732-477-1761
[email protected]
PROPERTY MANAGER
Jam Rabii
732-657-6760
[email protected]
CLOTHING APPAREL
Paul Meier
732-859-3002
[email protected]
WEBSITE ADMINISTRATORS
Jacob Hoehler
732-605-1131
[email protected]
Asst. Salvatore Piu
732-664-2688
[email protected]
Asst. Steve Lew
732-608-9938
[email protected]
LIPO, from page 1
of it for one hour. By the same token, to fully charge it, you
could pump 2 amps INTO it for an hour.
The bottom line: To figure the 1-hour charge rate you just
divide the milliAmpHour rating by a thousand and you get the
number of Amps you need. So if you have a 2000 mAh battery you can fully charge it in one hour by using 2 Amps. A
3000 mAh battery can be charged at 3 Amps for one hour for
a full charge, and so on. This happens to be called the 1C
charge rate, or the amount of amps you need to charge it in
one hour. The 1C rate is the standard for most LIPOs.
They’re normally designed to be safely charged in one hour.
C Ratings
Actually there are three different C ratings and you need to
understand the difference. They are:
1. The charge C rating.
2. The sustained discharge C rating.
3. The burst discharge C rating.
1. THE CHARGE C RATING IS CRITICAL! This tells
you how fast you can charge the battery. The 1C rate is how
many amps you push into the battery to charge it in one hour.
If a battery does not have a different charge C rating you have
to assume it’s a 1C battery. If a battery is marked as being
able to be charged at a higher rate you can charge it faster.
For example, my Hyperion batteries are marked as being able
to be charged at the 5C rate. A 2000 mAh battery then could
be charged at 5x2 amps (in other words 10 amps) and it
should only take 1/5th of an hour to charge it, i.e. 12 minutes.
You’re charging five times faster so it will only take 1/5th of
the time. Some of my Thunderpower batteries can be charged
at the 12C rate and these should only take five minutes to fully charge.
IF YOU TRY TO CHARGE A LIPO BATTERY FASTER
THAN ITS CHARGE C RATING, IT COULD CATCH
FIRE OR EVEN EXPLODE! For real. This has actually
happened to some people. As a matter of fact, it can happen
even if you’re charging at the right rate if the battery is faulty
or if the charger is faulty or you’re using the wrong charger,
i.e. one that is not designed for LIPOs. That’s why they tell
you not to leave a LIPO charging anywhere it could burn
something down. And whatever you do, do not mistake the
DISCHARGE rating for the charge rating!!! The discharge
rating is always a LOT higher than the charge rating.
See,LIPO , page 5
Ocean County Modelers Inc.
Page 3
Minutes of OCM
Meeting on
November 27, 2013
V
ice President Ed Hollema called the meeting to order followed by reciting the Pledge of
Allegiance.
Ed Hollema announced the absence of Tom Moore and indicated that the minutes of the last
meeting may be found on the OCM website. Jam Rabii agreed to take the minutes of this meeting.
Treasurer, Joe Acquisto read the treasurer’s report. It was approved by the members.
Field Committee:
Ron Syanovitz explained that “creatures” continue to dig holes in the runway and the Field
Committee is working on a solution to solve this problem.
Safety Committee:
Danny DiTursi reported that things have been quiet at the field.
Field Acquisition Committee:
Nothing new since the last meeting.
Old Business:
Ed Hollema indicated that the 3D event, which was highly successful, will probably be increased to a 2-day affair next year. He also announced that Lee Morey has been appointed as
the Committee Chairman for next year’s event.
Ed stated that there has not been much interest expressed by those who attended the “openday” that was recently held at Allaire Field for OCM members. Several members also expressed their negative outlook on Allaire as a flying field. As a result, the conclusion was that
the club will not pursue any formal agreements with the Jersey Coast RC Club for the use of
their field.
New Business:
Chris Segui asked about the calendar of events for next year. Ed Hollema indicated that he
expects a calendar of events to be put together by the beginning of 2014 and that it will include
events such as the Electric Fun Fly and the Pattern Contest. He encouraged any club member
who has a specific event in mind to bring it up at the OCM January meeting.
See Meeting, page 4
Page 4
Ocean County Modelers Inc.
Meeting, from page 3
Someone asked for an update on the idea of Training Night(s) that had been suggested at one
of the recent club meetings. This question led to a discussion of this subject which was concluded with a suggestion from Ed Hollema that a Training Committee will be put together to
come up with the necessary details. He also suggested the creation of an Education Committee
charged with setting up seminars and demonstrations dealing with old and new issues of interest to RC flyers. Lee Morey and Joe LaMantia were mentioned as two club members who will
be approached to serve on this committee.
The possibility of holding our monthly meeting at the field during the summer months was
brought up and followed by some discussion. Several people expressed interest in such an idea,
i.e. to hold a brief meeting at the field and follow it up by an opportunity for those interested in
flying their airplanes. This too, will be brought up for consideration at a meeting early next
year.
The subject of AMA insurance was brought up which led to a lively discussion. The outcome
was that, although this is a subject of much interest to many club members there is a significant
amount of confusion as to “who, when, where and to what extent” this insurance coverage applies. A suggestion was made that the club should look to find someone to be invited to speak
at a club meeting, perhaps from our AMA district office, who is well-versed on this subject.
There were no models of the month.
A 50/50 drawing was held prior to the close of the meeting.
Submitted by Jam Rabii.
OCM Holiday Party
F
or those of you have not yet sent in your payment to attend the OCM holiday party, you must do so now. The
absolute deadline for Treasurer, Joe Acquisto to receive your
payment is next Friday, December 13th. He is required to
submit a final count to the restaurant by Saturday, December
14th.
The party will be held at the La Bove Grande Banquet facility in Lakehurst (at the circle) on the evening of Thursday,
December 19th from 6-10pm.
<http://www.labovegrande.net/directions.html>
The restaurant will provide a full buffet-style dinner
(including appetizers, dinner and dessert). The cost to club
members and their guests is set at $15.00 per person.
Please mail your check, made out to OCM, to: Joe Acquisto, 1601 Cabot Avenue, Whiting, NJ 08759
Last Issue
to be Mailed
D
ue to the increase in
postage and the cost of
printing the newsletter, this
will be the last issue to be
mailed through the post office.
The newsletter will be
available on the OCMRC
website: <OCMRC.us>
Page 5
Ocean County Modelers Inc.
LIPO, from page 2
2. The sustained discharge is the main C rating you’ll see on a battery. For example, you
might see a battery marked 2100 mAh 20C. This means that the battery can sustain a discharge
of 20 times the 1C rate. The 1C rate for this battery would be 2100 milliAmps or 2.1 amps.
20x2.1 amps=42 amps. So you should be able to sustain 42 amps from this battery without
damaging it. How long could you fly your plane if you’re pulling 42 amps from that battery?
Well that’s easy: 3 minutes. This is 60 minutes divided by 20 because you’re pulling 20 times
more amps than the 1-hour discharge rate. If you want to fly longer, go easy on the throttle!
3. The burst discharge is often marked next to the sustained discharge. So for the previous
battery, you might see 2100 mAh 20C/40C. The 40C rating means you could get short bursts
of up to 84 amps without damaging the battery. 40x2.1 amps=84 amps.
Energy in the battery
Ok, most people are not familiar with this but it can be important to you if you start fiddling
with different planes, trying to get more out of them. The total energy of a battery is kind of
like how big your gas tank is in your car. In this case, the more cells your battery has, the more
energy you can store in it. It only makes sense that if you take 2 identical batteries then you’ll
have twice the energy. But two identical batteries in series will still have the same mAh rating.
You will have twice the voltage but the same mAh rating. However if you put them in parallel
you have the same voltage but double your mAh rating. That’s because each battery would only have to contribute half as many amps and would therefore last longer.
[Reprinted with permission from Johnson City Radio Controllers, Johnson City, TN; July 2012]
[Watch for Part II in a future issue of the OCM newsletter.]
A Fun Fly on New Year’s Day?
Correction
The November issue of
the OCM newsletter
failed to give credit to
Jacob Hoehler for taking
many of the photos of the
3D event. Both Tom
Moore and Jacob did an
outstanding job taking all
those photographs. Also,
Jacob’s name was inadvertently omitted from
the list of Website Administrators. My apologies to Jacob.
If you are interested in having, and would attend, a Fun
Fly on New Year’s Day, contact Ed Hollema by e-mail:
[email protected] and let him know. Sounds like great
fun—especially if it snows a bit!! Are you in?
2014 Membership Dues
Y
our 2014 membership payment, due in the amount of
$60.00 should now be paid. If is preferred that you
mail your check, a copy of your 2014 AMA card and a
stamped, self-addressed envelope to: Bill Martin, 683
McCormick Drive, Toms River, NJ 08753. There may be
an opportunity to pay at the holiday party, but not certain.
Membership dues must be paid no later than January 31st
to avoid an additional $25.00 late fee.
Page 6
Ocean County Modelers Inc.
JACKSON HOBBY SHOP
Full Line Hobby Shop
The Parts & Service Specialists
Summer is a great time to
treat yourself to a new plane!
Show your OCM
club card for 10%
discount.
(See store personnel
for details.)
STORE HOURS
Tuesday thru Thursday: 10am-6pm
Friday: 10am - 7pm
Saturday: 10am - 5pm
Sunday & Monday - Closed
We carry Lionel trains “for the kid in you”
L.G.B. “G” GAUGE
INDOOR—OUTDOOR
TRAINS
JACKSON HOBBY SHOP
2275 W. COUNTY LINE RD (RT 526), JACKSON
(IN BENNETTS MILL PLAZA)
732-364-3334
Credit cards accepted
Established 1969
THIS PAGE
INTENTIONALLY
LEFT BLANK
Wishing everyone a
Happy Holiday
And a
Healthy, Happy New Year
Ocean County Modelers Inc.
P.O. Box 569
Lakehurst, NJ 08733-0569
Next OCM Meeting
Wednesday
January 22nd
7:00pm
Manchester
Municipal Building