WHERE'S WALDO: LiPos have got to go
Wednesday, Dec 17, 2014 04:37pm
By Aaron Waldron
By Aaron Waldron
RC racing was changed forever when LiPo batteries were introduced, taking the place of Nickel-based batteries that had powered the hobby for decades. With more power potential, larger capacity, and lighter weight all packed into a smaller package, LiPo batteries were vastly superior in every way. Electric-powered RC cars desperately needed a new battery chemistry that was more powerful, easier to use, lasted longer than the final generation of Nickel-based cells. RC hobbyists had been switching to nitro cars and trucks for years, drawn by longer run times and, by the end of the road for NiMH technology, relative simplicity.
Now, RC racing as a whole needs another new battery chemistry before the hobby goes up in smoke.
Czypu-Drom, an indoor dirt off-road track in Germany, held a large regional race last weekend and used LiveTime scoring software for the first time.
Qualifying on Saturday went down without a hitch until it all burned down that night.
The pit area, not the computer program.
According to an online article from Neue Westfälische, an emergency call at 3:45 AM notified local authorities of a fire that had started inside the building and had already produced a lot of smoke. Experts concluded that a defective battery probably caused the fire, destroying a portion of the pit area and its contents - causing an estimated €100,000 EUR (about $124,260).
Unfortunately, the damage-causing fire wasn’t a single incident.
Nearly three years ago, a LiPo battery was responsible for another estimated $100,000 in damage, igniting inside a garage and destroying decades of RC car racing history. The garage belonged to Team Losi founder Gil Losi and his wife Janet, and doubled as a workshop for Gil’s son, Gil Losi Jr.
These are just the highest profile examples of the damage caused when a LiPo battery erupts. A quick Google search for “LiPo fire” yields over 800,000 results, many of which with horrific images of what went wrong - and what could’ve been worse.
Like this photo, from Helifreak - a RC helicopter forum.
And this photo, from the forum RC-Monster.
And this photo, from RCTech.
Here are five instances of considerable damage and potential injury caused by fires that ignited from LiPo batteries that were purchased and used by knowledgeable RC veterans - diehard racers and experienced enthusiasts. For an item that's "safe as long as it's used properly," there are way too many stories of potentially life-threatening destruction from "misuse."
Not all LiPo fires will damage something or hurt someone, but each new accident points out just how unprepared and uneducated racers and tracks are when it comes to the proper way to deal with a LiPo fire - like this screen capture from a video shot by Tom Cockerill at last weekend’s Christmas Race in Paris.
When drivers yell "marshal!" from the stand, they typically mean "turn marshal" and not "fire marshal."
I've never seen a procedural breakdown of the best way to respond to an RC fire, but I'm pretty sure "heroically rescue the burning vehicle from the racing surface while the qualifiying heat proceeds" is not step one.
Even when shorted accidentally, I can count the number of NiCD or NiMH batteries I can remember popping otherwise getting destroyed at the track - and not a single one caught fire or caused bodily injury. I’ve seen at least a dozen LiPo packs erupt in just the last 5-6 years.
Search through Google and see if you can find photos or a record of property damage or injury due to a NiMH battery failure from someone in the world of RC. I’ll wait.
Of course, there are a number of items sold many an even greater number of companies, that are supposed to provide for the safe charging and storage of LiPo batteries. These various bags and sacks are supposed to protect your pit area, not to mention anyone sitting near you, should the pack within suddenly erupt.
However, without any sort of testing and rating system in place to determine how well these bags actually work, you may just be adding extra fuel to the fire.
And even if they worked, of course, there’s the problem of getting people to actually use the bags. Most sanctioning bodies and large independent races require that LiPo sacks be used at all times. The problem with the rule, like many others made with good intentions, is that it’s completely unenforceable.
I found this photo within ten seconds of browsing photos from large national and world championship electric races I attended this year. At this race in particular, I was asked not only to erase photos I had taken of batteries being charged outside of the bag but also asked not to point out that it was a widespread problem.
Right, because censorship extinguishes fires.
Even if every race has 100% LiPo sack usage, and the bags themselves will in fact prevent the fire from spreading, that doesn't limit the fires to the pit area - as we've seen above. The biggest argument made for the carpet and turf tracks popping up around the world is that the tracks are easier to build in smaller indoor areas - which doesn’t bode well at all in case of a fire. There’s a bit of good news when it comes to this new trend, however, as most are non-flammable - though that’s no promise the adhesives used to hold them together, or the materials used to make the “off-road” obstacles, will be. These artificial surfaces may melt and create a new obstacle, and there’s not much research about the possible health effects of fires being extinguished by these flame-retardant materials (especially indoors), but if a fire does start on an artificial surface, chances are it won’t spread far.
Not that dirt is really all that flammable either, but I digress.
RC needs a new battery type, but the change may have to wait for happenstance. Like with Nickel-based cells before, today's battery "manufacturers" aren't actually manufacturing anything. They're simply slapping stickers on items made for them by the handful of companies that are actually capable of producing LiPo batteries with the quality and specs that RC customers expect, and lithium technology was built for more typical household items - cell phones, personal electronics, and full-size electric vehicles. And they're not fool-proof in those uses, either.
Even if the RC world is lucky enough to stumble upon a useful alternative that is created for a different application, the biggest resistance a new battery chemistry trying to change the RC world may face will likely come from the hobbyists themselves. There’s nothing currently available that matches the power-to-size/weight ratio of a LiPo pack, and today’s 3.7-volt cells are what was used as the standard to create today’s brushless motor designs for stock and modified racing. If the batteries change, especially to something that’s less powerful (like a 3.3-volt Li-Ion cell, for example), the motor designations will have to change, or the racers will - GASP - go slower.
But it needs to happen. LiPo batteries have been the overwhelming choice among RC enthusiasts for nearly a decade, and the fire problem is no closer to being snuffed out. We don’t need anymore photos like this one uploaded to RCTech: