djhoodrich
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80% more run time than lipo
- Thread starter Howdeedoodee
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Yea, all posable since it's just andriod after all. The cheapest most insecure mobile platform known to man, lol.
But again, also didn't want to get off topic.
Use a small cheapo thermal telemetry sensor to keep an eye on temps during flight.Got it
Just remember this is the same max wattage and amperage output as the other one you tested, just with double the cells in parallel for more capacity. So you will probably be able to fly 45 min? Maybe 50 min?
This is good and bad, you will have to remember to check the temperature of the cells as other have mentioned with a longer flight time before the cells cause damage. You said the smaller pack was hot, this one with longer flight time could end up getting a lot hotter and vent a cell with the start of a thermal runaway.
I realized today that most all of the threads on this forum and battery mods have to do with adding other 3S packs in parallel to the mavic smart battery of the same battery chemistry and style. Nothing has really been discussed in details about 18650 cells with battery mods, so I'm going to add all the following so you have a better understanding. After all, most RC stuff runs on Li-Po type packs, not metal encased cells like 18650 ones.
Like others have mentioned, check the temp often, preferably would like to stop before they get past the point of no return and go into thermal runaway. Thermal runaway can happen in that few seconds of the seal breaking, the flame shoots 6 to 8 inches and temperature of lithium burning can reach well over 800 Celsius.
I don't think the titan packs have any thermal fuses on them to cut this off from happening like drill tool packs and laptop batteries that have at least two thermal fuses in each pack to prevent this from happening with high drain tools.
*I think this is something Titan need to add to their packs if they are going to sell them and advertise them for RC use without offering proper BMS or ESC firmware updated to adjust for the difference between these battery types.
You can use a cheap thermal laser point gun for this to keep some distance if it's hovering, don't measure any metal, might cause a false possotive reading and the label might be a metal based label. If it gets anywhere near 70 Celsius I would shut it down. Thermal runaway reaction can start around 80 to 90 Celsius and continue for 5 minutes or longer and still look normal. As you will see in this video once it starts it can continue on its own for 3 to 5 minutes later, or even longer.
https://youtu.be/ZTzEHsJVZhA
He says not to buy these cells because the cell he shows advertises the are protected cells, and they are not. His recommendation has nothing to do with thermal runaway, all lithium batteries have the potential of this runaway. These days 18650 Li-Ion cells are one of the safest rechargeable batteries of done correctly with the required protection and BMS. This is one of my favorite sites to learn about batteries, and this will also explain how they are safe but only with proper add on protection.
http://batteryuniversity.com/learn/archive/lithium_ion_safety_concerns
Now remember using this 18650 battery pack with the mavic has no battery management systems (BMS) or thermal fuses in the pack, or protection circuits. So yes, by changing from one battery type being Li-Po based that the mavic comes with to another type like the 18650 Li-ion type is a risk. Even using the Mavics own battery protection from the smart battery won't work as we already discussed because of different ways of discharge curves and voltage minimums and maximums.
An experiment was done using X-Ray and thermal imaging to capture and see what's happening inside the cells in hopes to figure out a new manufacturing way to make them even more safer. I don't care for vapping sites and how the measure 18650 cells with a category called pulse discharge current, basically all pulse discharge current rating are out of the manufactured specs of the cell. But this site did a good brief write up of the X-Ray thermal runaway experiment:
https://batterybro.com/blogs/18650-wholesale-battery-reviews/19582595-what-s-new-this-week-in-lithium-ion-battery-technology
Safety of Li-Ion cells is all about the correct rated cell performance for the load and application being used and the BMS. This article has a good break down of what the BMS does half way down the page:
http://www.batterypoweronline.com/main/markets/testingservices/safety-and-preventing-thermal-run-away-in-large-li-ion-batteries/
But as people buy cheaper over rated miss advertised and fake cells on the internet with devices that don't use any BMS because they just want to make sales and don't care about safety and can't be help responsible with other country laws then we have problems like the hover boards and cheap LED flashlights that come with ultrafire fake batteries and chargers that can over charge the battery also.
If you have any hissing sound or see any liquids or malformed PVC wrapper from any of the cells indicating the seal vented then leave it outside overnight.
In the past, I have dug a whole to throw them in. I have an ammo case with sand for batteries that have shorted out, but don't seal the ammo case closed, just rest the lid over top.
Now that you understand the risk, have fun and most of all be safe.
Scott
MacIak
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He's a bit optimistic but means 30 indeed..
If these batteries give a 50 min run you'd be able to make it 20 out, 20 back.
MacIak
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djhoodrich
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digdat0
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20 miles is optimistic too .. i ran my p3 for 52 mins distance, i was going 34mph+ (Mavic is slower btw) and i did 14.5 miles out and back (77k feet) and landed 1%. I think 12+ miles is realistic
And on Stock RC too 
Here's the data for that flight, its not a mavic, but not many folks have done 50min+ flights on any AC! Airdata UAV - Flight Data Analysis for Drones
digdat0
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MacIak
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20KM Dig...mine does 0.77km/min pessimistic.20 miles is optimistic too .. i ran my p3 for 52 mins distance, i was going 34mph+ (Mavic is slower btw) and i did 14.5 miles out and back (77k feet) and landed 1%. I think 12+ miles is realistic
WoooooHoooooo I knew we would prove the doubters wrong.
50 min flight on Titan 3s 7.0ah Endurance.
What works in theory doesn't allways work out in practice.
I've done my 3s 7.0mah Endurance with aluminium heatsink and on thermal telemetry sensor got 56 degrees but now looking at djhoodrich video I needn't of bothered.
Video at weekend, in the UK the weather is mostly........CRAP!
MacIak
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56deg is pretty hot. You could hold your hand on that for a couple of secs..
digdat0
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From the battery university.
The dry solid polymer battery requires a temperature of 60–100°C (140–212°F) to promote ion flow and become conductive. This type of battery has found a niche market for stationary power applications in hot climates where heat serves as a catalyst rather than a disadvantage.
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