To be or not to be, That is the question…

If by “to be” you mean a flying quadcopter, and “not to be” you mean a pile of charred ashes…

Due to the worry that we will end up with the latter if we continue using the battery we have, we are looking into investing in a new LiPo. After spending the past hour or so perusing over some witty banter between many flight hobby enthusiasts on the topic of “puffy LiPos” and the dangers included in using them, I have come to realize that yes, it is potentially dangerous to operate with puffed packs, but many people have been doing it with no consequences. While it is true that you must keep in mind your craft could go down in flames from any possible overpuffing and consequential bursting and venting of the pack, or puncturing and burning of the pack, in reality, you can minimalize these events from occurring by just being careful. Not operating a pack that is puffed so badly that it holds pressure, meaning not operating a pack that is puffed and hard, and any added pressure could burst. Monitoring puffed packs during current draw, to be sure they don’t become puffed enough to burst and vent. Monitoring the packs as well for heat, it appears 140F is the “bad zone” for LiPos, so letting batteries cool before they reach that point is always a good idea. And in general, just being careful with them. From what I have read, yes, there have been catastrophic failures, where houses burn down, but LiPos seem to only have a bad name from a few cases. Plenty of other people have blatantly cut into their packs, knowing what to expect, and yes, when charged, you should get a fire, but if you are prepared, it shouldn’t be the end of the world.

A note to anyone on disposal of LiPos: From what we have found, they are landfill friendly, once discharged completely. This can be done numerous ways, some people hook them up to a power draw, and just let them drain, then they will cut them open and submerge them in a saltwater solution for a few weeks, and dispose in a landfill. Others simply place the whole battery in saltwater. The water conducts slightly, so it drains slowly directly through the contacts, and eventually you have a completely dead battery. Now, whether you need to cut open the packs and re-submerge, I don’t know for sure. I would imagine the battery should be fine as-is, and ready for the landfill. Keep in mind these are all the “safety conscious” people. Personally, I would prefer (and there are plenty who do this) to set the battery in a firesafe area (nothing that can catch flame within at least a few feet), and puncture the pack (adding water optional), as fully charged as possible. BE CAREFUL THOUGH! This can be extremely dangerous, and while LiPos don’t seem to be as bad as their reputation, I am not responsible for giving you an idea that you carry out dangerously on your own.

On that note, we are still worried about our pack. It appears puffed, and while this whole time we have been thinking it was just an air bubble between the cells and the covering shrink wrap, we are getting nervous that in the case we are wrong, and the battery does catch fire, and it happens to be on the quadcopter at that time, we would be down a very fun toy… So tomorrow morning, we are very carefully stripping the shrink wrap off of the cells to compare them and verify if any or all are puffed, or if it truly is just an air bubble.

Also on the agenda for tomorrow is adding the LCD screen we bought a while ago, which means soldering plenty of tiny pins, my favorite! And adding a roll cage to the quad, so upon a collision with the ground (something we really don’t want to have happen) the two sheet metal strips bent into two U shapes, and crossed over the electronics, will take the brunt of the force, and the electronics themselves will not.

~Will

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