Grandmother suffered vascular dementia in her last years and needed constant attendance. During those years, Grandfather (who was an inveterate model airplane flier earlier in life) undertook to treat some of the problems modelers were facing with their high-energy-density lithium polymer (LiPo) batteries, use in their radio control electronics and in their propulsion motors.
Lithium polymer batteries are absolutely unforgiving of over-voltage charging; Also physical damage, quite common in model airplane crashes. Resultant battery fires are explosively violent.
One of the tests Grandfather did of a prospective LiPo fire container can be found here.
And here is a description of a method for avoiding overcharging.
The conclusion that LiPo fires could not be safely contained by modelers was widely accepted, but the parallel charging of individual cells took awhile. The manufacturers of battery packs eventually installed taps between the series-connected cells and adapted their chargers for parallel charging them.
The problems presented were widespread: Laptop computer and cell phone battery fires were widely publicized. Problems with shipping lithium batteries in commercial aircraft were subjects of FAA regulation and Boeing had major engineering expenditures on , among other things, a heavy containment box for the 787 Dreamliner battery.
Pictures of the test of that box were published at the time, but Grandfather cannot find them now: They showed the box bloated by internal pressure, but it did not rupture.
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About the Author: RD Blakeslee is a nonagenarian in West Virginia who built his net worth by only investing in that which can be enjoyed during acquisition and throughout life, as opposed to papers in a drawer, like stocks and bonds. You can read more about him here.
Original oil painting by: Grandfather’s wife
Since 9/11, our lives have been circumscribed by the need for “national security” and the flying of radio-controlled model airplanes could obviously be used for a terrorist attack. So, there has been a sometimes contentious process for arriving at procedures for permitted model flying.
So much is that way: 40 years ago, I could go into a local hardware store and buy dynamite for stump removal!
Yet, people can own drones. Go figure.
Bill, most “drones” are small multi-copters, which modelers had been building and flying for years before their modern “invention”: https://www.rcgroups.com/aircraft-electric-multirotor-drones-790/?s=7ae433016eb7e56454205104bba101b6&
Congrats on your retirement!!!!
Thank you Hazel! I was an early “F.I.RE.” guy (Financially Independent, Retire Early – my dentist told me about that acronym after she had read “Grandfather Says”).
I “retired” in 1974-, over half my lifetime ago. But a good many of the episodes on Grandfather Says” happened after my so-called retirement.
That’s alarming to know those batteries are on today’s airplanes. It’s just one more reason not to fly in this day and age.
Corporate users of lithium technology have learned to deal with the safety issues better than the kids flying model airplanes that I tried to help, Dean
Another interesting adventure! You are a well traveled man who is a jack of all trades.
Thank you, Kingman.
Part of my satisfaction now late in life is that I do not wish anything had been different in the past in my life. Some folks do and I think they are wasting their self-respect by doing so.