the battery clinic - 2012/05

92 Model Aviation May 2012 www.ModelAviation.com
Reader’s battery
questions answered
The PowerLab 6 setup
with laptop for charging.
Professional engineer Peter F. Richiuso P.E. wrote:
“I prevailed on one of my colleagues in the analytical
chemistry lab to analyze the gas in a puffed LiPo I had. It turns
out that the gas is methane (CH4). I was surprised at first, but
after reviewing the LiPo chemistry and discussing it with the
chemist (Ph.D., in fact) it is very logical.
“One of the electrodes in a LiPo cell is lithium oxide
infused in a graphite matrix (carbon). The hydrogen for the
methane comes from moisture in the air when the batteries
are assembled. Lithium metal will react with water to produce
lithium oxide and hydrogen. The graphite matrix supplies the
carbon that combines with the hydrogen to form the methane.
There’s a limit to how low the humidity can be maintained
since the materials used can be hazardous if they’re very dry.
“Hard charging or discharging of LiPos causes heat to be
generated, which accelerates the production of methane
although the methane can form even if the battery is not being
used due to self-discharge.
“The results of all
this is that it should
be okay to use a
puffed battery as
long as the battery
has retained most of its capacity.
The amount of methane generated
is rather small and once all of the
internal moisture is converted, no
further gas generation will take
place.”
Cellpro PowerLab 6
I received the new FMA Cellpro PowerLab 6 Multi-
Chemistry 1000-watt Battery Workstation for review. Upon
opening the box, I was greeted with this notice on the inside
cover:
“At Revolectrix we’re just as concerned about the
environment as our customers are. The manual for this
product is available at: www.revolectrix.com.”
And all 83 pages are in English (as are all of FMA’s productuser
guides). Considering that most people ignore manuals
until they get frustrated just poking buttons or have lost
the manual by the time they discover they need to read
it, it seems like a good idea. A bonus for those considering
acquiring this great charger is that you can study its
operational features before making the big decision.
The PL6 comes with an EC5 connector on the #10 AWG
input power cable. To connect to your power source—
whether it is a battery or DC power supply—you will need
some means to link to the EC5 connector on the power cable.
Male 5mm bullet connectors will do the job, or you can order
the optional plier clip assembly.
The plier clips are monsters, rated at 60 amps. Because I am
set up for banana plugs on all my charging equipment, I used
the best gold-plated, high-current banana plugs I could find
and replaced the monster clips.
Before you can use the PL6 you also must get the proper
adapters for the balance leads on the packs being used.
The preset screen from the
PowerLab 6 charge control
software.
FMA PowerLab 6.
Figure 2a shows the power cable with EC5 connector and giant alligator
clips. Adapters (shown in Figures 2b, c, and d) are required to interface
with various battery packs.
PLUS:
> Reader investigates
LiPo swelling
> PowerLab6 reviewed
> Laptop lithium packs
> Laminating material
used as modelcovering
the battery clinic
Red Scholefield
[email protected]
The FMA Direct website (listed in
“Sources”) has a listing for specific
battery compatibility. The company
offers interfaces for nearly any battery
you might encounter.
The ones shown have the parallel
socket for daisy-chaining for parallel
charging. Power connection is through
normal banana plug sockets. You will
also need the FUIM3 PC USB interface
cable to connect to your computer.
The battery power lead uses standard
banana plugs.
Information on the website states:
This 1000-watt battery workstation will
charge, discharge, monitor, or multiple
cycle any current or future battery
chemistry. Future battery chemistry?
FMA must have a better crystal ball than
I do.
The PL6 is built on the PowerLab 8
technology, with programming similar
to the Cellpro Multi-4 (if you have used
one of those). It is geared toward the
power user, but is simple to operate,
affordable, and meets all of our battery
needs.
To discuss in length the extensive
list of features and capabilities of the
PL6 would take up far more space
than I have in this column. The PL6, in
combination with the charge control
software
downloadable
from the
FMA website,
offers virtually
unlimited access
to charging
parameters. With
Windows, it’s
easy to alter as
many as 100
settings for any
of the 25 user
presets, gain access to 50 additional
library presets in the unit, or tap into the
PC library.
Major features include advanced
power management to help you set up
and use existing DC power supplies or
your lead battery acid, faster individual
cell IR readout, and support for safe
parallel adapters (PL6 and PL8 share
the same adapters), which enable
charging/discharging multiple packs
simultaneously by piggybacking the
adapter modules.
It also features an expansion channel
mode for turning multiple PL6s into one
workstation with interlocking units, and
regenerative discharge that will dump
battery discharges into your source
battery. You can set input power supply
levels to protect your source from
overload.
Although a computer connection is
unnecessary to use the PL6, it makes
the operating parameters easier.
One benefit is the ability to plot the
individual cell voltage, pack voltage,
current, capacity, and power supply
voltage and current.
You can also control the PL6 directly
from your computer keyboard. I
don’t recommend charging batteries
on carpeting. I do all charger
evaluations and testing on my metal
file cabinet and the system is never left
unattended.
The default setting for plotting curves
is a black background with white grid
lines, x-y axis numbers, and selectable
colors for the individual cell voltages.
As you might expect, printing the
chart with a black background does a
number on your printer ink supply. No
problem; just switch the background to
white. Also, make sure you change the
text on the x-y axis to something other
than white before you print.
As with other FMA charge systems,
software updates can be downloaded to
your PL6 to keep it current.
Here are the specifications for the PL6:
• Battery types: LiPo (1s to 6s balanced,
1s to 2s unbalanced); lithium ion (1s
to 6s balanced, 1s to 2s unbalanced);
lithium manganese (1s to 6s balanced,
1s to 2s unbalanced); A123 or lithium
iron phosphate [LiFePO4] (1s to 6s
balanced, 1s to 8s unbalanced); Ni-Cd
(1s to 19s); NiMH (1s to 19s); 6 volt; 12
volt; 24-volt lead acid batteries (flooded,
gel)
• Pack capacity: 20 to 360 mAh
• Input voltage: 10 to 32 volts direct
current (VDC), reverse-to-polarity
protected
• Input current: 1 to 40 amps, software
limited
• Power conversion: Synchronous DC/
DC converter
• Output battery charge current:
Adjustable range 10 mA to 40 amps,
limited by 40-amp input current
• Battery discharge current: Internal
discharge 10 mA to 8 amps, 50-watt
maximum; regenerative discharge 10
mA to 40 amps, 1000-watt maximum
• Continuous maximum output power:
408 watts at +12 VDC input, 1000
watts at +30 VDC
• LCD: two-line, 16-character, light
gray/blue backlit
• Size: 5.70 x 5.57 x 3.40 inches
With a price of $164.95, the PL6 is
hard to beat. Necessary adapters can be
purchased individually or in bundles.
Laptop Battery Balancing
Are laptop batteries balanced? This is
something I have always wondered. My
five-year-old laptop battery finally gave
up the ghost, so I opened it up to see if
or how balancing was accomplished.
The pack was a 2P3S configuration,
giving a nominal 11.1 volts with lithiumion
cells. There was plenty of circuitry
with connections to each of the two cells
wired in parallel.
Alternative Covering Material
Fellow club member Jim Hales has
found that 3 mil laminating material
makes a tough and inexpensive covering.
Your local laminating shop throws out
ends of rolls. Ask them to save some for
you.
One side of the laminate has heatactivated
adhesive. Jim is a vintage
model fan, as you can see by his electricpowered
Esquire model.
Flying Season
Flying season is here for most of you.
Make sure you give those packs that
have been resting during the winter a
couple of cycles to make sure they don’t
let you down.
Contact Me
That’s all for this month. I enjoy your
communications. No email access? Then
drop me a note at The Battery Clinic,
12219 NW 9th Ln., Newberry FL
32669.
SOURCES:
FMA Direct (Cellpro PowerLab 6)
(301) 829-5533
www.usastore.revolectrix.com/Products_2
CellproChargers