File: 11gee.ht1.doc
[Headline: Ready, charge, fire!]
Batteries were the subject of several emails that I received from MA readers.
First was a news story about a young girl who charged her cellphone battery overnight. She stuck the phone under her pillow while it was charging and went to sleep. To the surprise of no one reading this, it overheated and charred the bedding, but, miraculously, did not start a fire. I think it’s a pretty fine product if it did not burn the house down after being abused like that.
Next is a tale of excitement that happened at a public event. Indoor RC pilots were demonstrating their aircraft in a large carpeted room. A charging station was set up, and a three-cell LiPo battery pack was setting on top of a LipoSack, “gassing up.”
Another modeler came along and hooked-up a four-cell pack. Oops! The charger setting was wrong, but with a push of the button it was reset for four cells. Never mind that the three-cell pack was still attached.
Moments later, there was a loud “pop” and the fireworks began. Several people told me how a group of stunned pilots at the event stood frozen with surprise, until one quick-thinking pilot dashed over, wrapped the hot battery pack in a big LipoSack, and saved the day.
I’ll guess that everybody on the scene already knew the rules, and that those responsible felt bad about the situation. Hey, if a bunch of experienced fliers can allow a goof like that, we average types really need to increase our vigilance.
Lessons learned:
1. Setting the pack on top of a fire-resistant bag while charging is good, but putting it inside is better.
2. Shared charging stations need constant adult supervision to make sure that the distractions of a big event don’t lead to trouble.
3. Having sand buckets ready is a great idea for an indoor venue.
You don’t need to attend a big event to have this sort of excitement. Nick Trubov did it in the comfort of his own home, thanks to a similar slipup with a LiPo charger. He forgot to change the jumper setting from double to single cell. His battery was unforgiving, and Nick soon heard an explosion in his garage that could have led to serious structural damage.
He had the battery in an ammunition can while it charged. When it exploded, the can’s shape changed from rectangular to cylindrical and the lid was blown across the room. A tiny battery released that much energy! Holes drilled in the the sides and lid of the can weren’t enough to vent the battery gasses.
I recently asked readers for information about LiPo batteries failing while inside used ammunition cans. Such containers would appear to be a good choice for charging LiPos, but I wanted to hear how things worked out in emergencies.
Nick’s story confirmed the speculation that the cans are not heatproof and would not contain a fire. However, they are sturdy and useful in reducing damage.
Nick concluded, “I now keep my Lithium packs in sacks specifically designed for this purpose. I also have made it a habit to charge the darned things outside away from the house.”
I appreciate Nick’s kindness in sharing this information. Please, dear readers, if you have a good story or topic suggestion, email me. We can all benefit from the exchange of knowledge.
Pad Your Can
Don Whitlow had a similar nugget of wisdom that’s simple, but brilliant. He uses steel ammunition cans to store LiPos, but worried about the heat during a fire.
He went to a hardware store and got some of the little pads that plumbers use to insulate building structures from the heat of sweating pipes. Don put the pads in the bottom of the cans to improve insulation and direct heat away from whatever the can is sitting on. Is that a good idea or what?
It won’t fully contain a fire, but it will buy more time to deal with an emergency. We don’t charge batteries unattended (right?), so it’s simply a matter of getting the smoking battery to a safe location where it can be extinguished or left alone to burn. Nice thinking, Don!
First AED
Randy Cameron, AMA District VI vice president, forwarded some good information to me from District II Safety Coordinator Al Kanser. I am happy to reprint it.
Although our sport is enjoyed by all ages, some clubs find that the average age of their members is … well, pretty old. Al wrote:
“This was driven home for the Oneonta [New York] RC Flyers when a club member suffered a massive heart attack at the field. He was given immediate CPR and emergency squads were called by cellphone. Everything that could be done at the time was done, but unfortunately, the member passed away a few days later in the hospital.
“In reaction to this sad incident, the Oneonta RC Flyers bought two automated external defibrillators [AEDs] and had eight volunteers take a free CPR and AED training course. They will have these units on hand at the club field and at club-hosted events. These devices cost $1,200 each. At this time, there are less expensive units available, including factory refurbished units.
“For a cost of $600 to $1,100 and a few hours [of] attending a free course put on by either the American Red Cross or the [American] Heart Association, you can give a fellow club member an extended lease on life if [he or she] happen[s] to be stricken by a heart attack.”
This idea will not work for every club, but if you have a large, well-financed organization, it’s worth looking into. I urge everyone to consider taking a first aid and CPR class. Imagine a sudden life-or-death medical crisis and how you might feel. Would you stand around not knowing what to do or have the training to help? I’d prefer to know that I did everything possible.
The “Hole” Wing
Model aircraft sometimes fly with structural features that would ground full-scale airplanes. Scott Ramirez recently proved this by test-flying his Ryan XF2R Dark Shark. The conversion from a T-28 ARF kit is still in progress. Changes include a motor-shaft extension and wild, flow-through landing gear wells.
Scott said he’ll add some plywood skin to cover the openings, although the airplane flies fine as is. Our models get away with murder, aerodynamically speaking.
Mass Launch 2014
Charlie Grant’s famous 1954 Cloud Tramp design is a classic all-balsa, rubber-powered rise-off-ground sport model intended for new and experienced builders. For many years, enthusiasts of the aircraft have participated in the Charles Hampson Grant Memorial International Mass Launch Of Cloud Tramps. Around the world at the same moment, fliers launch these airplanes. The whole thing is just for fun.
Mike Myers, past president of the Society of Antique Modelers (SAM), convinced me to build a Tramp and participate in this year’s event, held on August 2. During the mass launch, he sent his own aircraft over to circle tightly with mine. One airplane flew clockwise and the other went counterclockwise, so there were some real thrills at our end of the field! After a dozen near-misses, his Tramp touched down a half-second before mine.
It is with great dignity that I say to Mike, “Neener neener neener!” Of course, he later cleaned my clock in the five-flight Postal Contest, but who’s counting?[dingbat]
SOURCES:
LipoSack.com
[email protected]
www.liposack.com
Cloud Tramp homepage
www.mikedparker.karoo.net
