Lithium ion plane battery

If I was going to fly for 30+ minutes, I would bring a lawn chair.

It is amazing that the battery and magnet technology has come so far that flights are so long they are boring.

I thought he was about to say spot welders are illegal in England...

Tom, it would be interesting to revisit this in 2020. I would like to see you measure the actual flight time of both to their limits.

realise it might be boring but you really need to verify the "theoretical" time for the LI-ION pack

Mount the plane. You can let it run and if it's a hot day, you've got a fan!

Wonder if there some kind of RC plane distance record could try and break.

Lithium ion and a little supercapacitor for turbo mode stuff.

One thing that sprung to mind as you were talking about the difference in internal resistance between the packs is that the internal resistance of a cell is no different than any other resistance; it dissipates power proportional to the square of the current, so the higher the drain, the better the li-po should perform relative to the 18650s. Since the draw was quite low in this test this may not be a significant factor, but I thought it was worth mentioning.

I've always wondered about this, thanks for the video!

Thanks for the extensive test. I use li Ion cells for my model cars. Work like a charm !

I never knew Tom was a member of the So Cal Surf Club

Hi Tom. I enjoy your channel. I experimented with long duration flight around 1995. I used a small sailplane with a 1.5 meter span, a 6 cell 800 mah NiCd pack and was able to fly for almost 90 minutes. The energy stored was 8.6 watt hours and my average draw was about 4 watts to sustain level flight. Prop was a Robbe 6x3.5 folder and motor was a Graupner Speed 400. I don't remember which wind I used. Average current was about half an amp. I had to do this just before sunset when thermal activity was nonexistent and no wind. I found that trying to climb more than the minimum required to stay airborne shortened flight duration and thermals are bad because there is a lot more down air than up air. Even a little down air increases your average watts. Lipo batteries of even the poorest quality would give around four times the duration. I would have had to worry about the transmitter batteries and bladder control issues with 6 hour duration flights not to mention being bored out of my mind.

I think the spec sheet for Li-On cells shows a 2.7v discharge minimum

Just for the craic of it, I alo made a 2S2P pack out of 18650's, tested it on my 9inch quad, it flies for about 10 min straight... Also converted all my drills to Li-Ion with the appropriate BMS boards. Just soldering these is a bit tricky. Nice one Tom!!

Great informative video Tom, thanks! You point out the li-ion weight/energy ratio is superior but the current draw is the systems drawback. How about adding a capacitor to increase available voltage/amperage for short bursts of acceleration with the li-ion? Or even using an extra cell and dropping the volts to increase amps?

Hehehe I laughed my ass of when you said "Incredibly Boring" cause it's so so True 😂 Nice video

"Energy density per mass" Energy ----------------- Mass/Mass Sorry i just had to point that out :)

You mention about spot welders being expensive in the UK. But that's why I'm always so amazed with your channel... You're in the UK, but you don't let that hinder your creative and inventive mind. It's really admirable. I often see American youtubers with easy access to large power tools, large cheap professional garages, less restrictions on buying chemicals. The US is a country where people have more freedom to pursue things. The UK by comparison... You can't even easily get hold of dry ice, or caustic soda, borax, etc. And we're lucky if we have a small shed to work in. But the fact that you don't give up, and don't let the loony laws, prices, and restrictions hinder you is inspiring to me. Great work, keep it up.

Thank you soo much I some how watched the night before I had a test from technology