The Battery Clinic
Red Scholefield | [email protected]
Are Eneloop batteries the answer?
I have been getting numerous questions about Sanyo’s Eneloop batteries, but I have no personal experience with them. Sanyo’s web page provides a comprehensive look at this improved NiMH technology, but how they behave in our modeling environment is of more importance.
Stefan Vorkoetter has done extensive testing that indicates Eneloop batteries are a good choice for flight-control and transmitter packs. One of their main features is a low self-discharge compared to conventional NiMH cells, as shown in the graph included with this column. Stefan’s aviation/modeling website is well worth your visit.
Since Eneloop cells are not available with solder tabs, it is recommended that you purchase built-up packs with welded tabs. A couple of sources for these are Hangtimes Hobbies and Radical RC.
Midair—E vs. Glow
At our club field on a clear and calm morning, two models were sharing all of Mother Nature’s crystal-clear blue airspace: John Castronover’s new electric-powered Taurus and Neal Christensen’s Skylark. And then the old adage came to pass; sometimes you’re the windshield and sometimes you’re the bug.
The Skylark made it back to the strip and landed safely, sustaining only minor damage to the underside of the wing. In a few days, John had rebuilt the Taurus from the mess shown in one of the photos, and it looks and flies as great as it did before the incident.
While cruising the Internet, I saw a good case for use of the tough-to-remove W.S. Deans Ultra Plug. See the photo of an autogyro.
Also included in this column:
- Surviving midairs
- VoltMagic upgrade
- FMA Direct’s Cellpro Multi4 charger
VoltMagic Updates
VoltMagic introduces its updated 2R-20: an onboard voltage monitor weighing only 7.3 grams (0.25 ounce). The unit allows you to custom-configure your power setup to use a 4.8-volt, 6.0-volt, 7.4-volt Lithium, or 6.6-volt A123 battery pack, or use it just as a voltage regulator.
There are 20 ranges for Averaged Voltage (AV), and two selectable ranges for Peak Low Voltage (PLV) to record the lowest voltage. There’s even glitch (a missing or bad signal pulse) and fail-safe detection. Following are more details about the 2R-20 unit’s features.
AV
AV is adjusted to warn of low mAh remaining in a battery or incorrect output from a regulator. It shows a steady display of the current voltage. Each LED represents a 0.1-volt increment. There is just one monitor for all applications, and you can fine-tune the colored LED bar graph to match your system and your preferences.
PLV
PLV indicates whether or not the electrical system is capable enough for the servos. Below a certain threshold, this shows the lowest voltage at the receiver (or wherever it's connected) in 0.1-volt increments.
There are two ranges from which to select: Normal and Low. The Extended PLV feature temporarily shows an extra 0.2 volt of PLV on the high end for an early warning. With a sample rate of roughly 1,000 volts per second, this is the fastest onboard monitor available.
Glitch and fail-safe counting
This unit is selectable for glitch (Pulse Position Modulation [PPM]) or fail-safe (Pulse Code Modulation [PCM] or 2.4 GHz with an adjustable fail-safe). The counting is smart, so several glitches within a short time period are classified as the same event.
A glitch from a PCM or 2.4 GHz receiver indicates a fault (possibly a reboot). With a traditional PPM receiver, a glitch usually indicates a failure to receive the transmitter's signal.
For further details, instructions, and even a demo, visit the VoltMagic website.
Cellpro Multi4 Multichemistry Charger
Why did FMA Direct produce another generation of the Cellpro charger? The company received many requests from customers about specific features they would like to see in their chargers. Occasionally these things can be added, but often there is not enough memory left in the microcontroller to make it happen. Sometimes, making a change that one customer wants is not what other customers want.
Modifications require countless hours of meticulous firmware updates and debugging before firmware updates can be made available. So a more powerful microcontroller, in combination with the new Open Architecture Presets philosophy, enabled FMA Direct to meet many requests.
This alteration was done in an efficient and superior way. Adding a new feature, tweaking parameters, and fixing problems is as simple as correcting or creating a preset. Consider one scenario that creates an array of issues.
Let's say Customer John wants his charger to balance A123 batteries at 100 mA as opposed to 200 mA. This is a major decision for any charger manufacturer.
- Does it update the firmware to change the balance current?
- Will other consumers like the change?
- Does the company add a capability within the user interface to allow John to set it the way he likes without affecting other users?
- Is there enough memory to effect the change?
If you read about how FMA Direct or any manufacturer handles these things, it is usually an inefficient process. The results often please some customers while others complain.
Enter Open Architecture Presets. Changing the balance current, the type of balancing, or how far along in the charge process the balancing begins becomes possible. Go to the preset you want to alter in the Charge Control Software (CCS), find the parameter you want to adjust, and you're finished. You now have a customized preset for your specific battery type, situation, or application.
Throttle Lock: Jim Meyer wrote:
"Your article on a throttle lock in the 01/09 issue of MA is a very good idea. However, when I tried to program my DX6i, I just could not shut off the motor.
"The manual shows throttle to throttle as an example but after calling Horizon I was told that it could not be done. When I asked about changing the momentary push button for the throttle cutoff to a toggle switch, I was told that if they were to do this it would be a liability issue if I turned the switch off in flight and crashed. What are your ideas?"
The whole purpose of the throttle-lock idea is safety, so that you don't inadvertently hit the throttle stick before you are ready to fly. Since when are dead-sticks a liability issue for the radio manufacturer?
When I pull my throttle stick all the way back, the motor stops. What's the difference? I have no idea whether or not it is possible to do the throttle thing with your specific radio, so I can't comment on that.
Has anyone been able to set this up on a Spektrum DX6i or other model? If so, please drop me a note on how you did it so I can share the information. —MA
Sources
- The Battery Clinic
12219 NW 9th Ln. Newberry, FL 32669
- Sanyo
(619) 661-1134 http://us.sanyo.com
- Stefan Vorkoetter
- Hangtimes Hobbies
57 Cedar St., Suite 6 Babylon, NY 11702 http://www.hangtimes.com
- Radical RC
(937) 256-7727 http://www.radicalrc.com
- VoltMagic
Box 1518 Estacada, OR 97023 http://www.voltmagic.com
- FMA Direct
(800) 343-2934 http://www.fmadirect.com
Transcribed from original scans by AI. Minor OCR errors may remain.
