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Old May 11, 2015, 11:25 PM
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As much as I'd love to think its true, 5A at ~32mph is possible, but it requires very disciplined throttle management, something I just do not have. Also, on a 10aH battery, you only want to run 8aH of that so that you don't run your battery down to the bottom. So, figuring 8A available you should be able to fly just over an hour total, but the truth is, taking off and getting to cruise altitude will take more than your normal cruise will. Yes, the descent will take less than the cruise amps, but its best to have something available for contingency too.

Keep in mind that Lipos really drop off rapidly once you get to 3.6v/cell. I try to land with 3.7v/cell resting (so it may be 3.5-3.6v/cell on approach) and it seems that the RMRC batteries due drop quickly to <4v/cell, with most of the "fuel" being delivered in the 3.75-3.95v/cell range. That could just be my usage though, your mileage may vary.

That said, the current usage will go up as you add more batteries. The cruise current isn't a fixed variable, it does vary depending on your weight. With two of the 12.4's your range will go up, but so will your consumption so I wouldn't be surprised at all with a cruise draw in the double digits.

Good luck on your theorycrafting and decisions, I look forward to hearing what you come up with!
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Old May 12, 2015, 03:38 AM
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I figured but li ion have slightly different characteristics to lipos but i understand what you're saying. If i get 2c liFe 40A batts the flight will not be exactly 8 if i plan on travelling at 32mph. It would be more like 5 to 6 due to weight, possible head wing and the unpredictable (known unknown possibilities)

But I'm pretty stoked for the graphene batt revolution, the only thing I'll be worried about is over heating and weather
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Old May 12, 2015, 11:47 AM
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True, the li ion batts can be run down a bit more, but you want to make sure you're powering your flight control stuff from something with stable voltage. I watched some colleagues run a skywalker for over 4hrs on li ion but when that voltage got low, their power module failed to deliver 5v to the receiver and pixhawk, and both browned out. This was even though the li ion pack was still >10v. I think you have this covered by the second battery as you mentioned above.
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Old May 14, 2015, 01:50 AM
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since li ion can carry the same amparage of a lipo with half the size, it should theoretically double my flight time (almost double) so 40a at about 3kg or Li-Fe since those are even lighter for same amps. then add a separate battery for the gear, 12v li ion, 6000mah with a capacitor to keep the voltage steady.
The cam used bout 100mah, vtx 400mah, other, 500mah. 1000mah consumed in an hour so 6hours.

tho i'll need to start selling high power with high capacity batts at affordable prices and light weight (alibaba sell naked batts for well cheap in bulk, just buy, solder, solder balancing pin and brand them power max or max power and sell on ebay and amazon) cuz $400 is just mad. this will help fund my project.

but i don't know the configuration of balancing pins please tell me how if u know

so overall, what do u think
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Old May 14, 2015, 03:44 AM
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More air time please!
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I think it will work! you will see why here http://www.rcgroups.com/forums/showt...0#post31355241

If you guys want to pop over there and post the Amps/watts that monster of a mother ship racks up on take off... or (WOT) and the cruise Amps... I can give some options of configurations. max amps... and weight as well.

I have only tested 4S, but a 6S with the 4s data i have graphed and logged will provide accurate info on 6S as well.
1.primary goal is to improve/ fine tune the motor and prop combo... till u have a sweet efficient system for a given task... (cruise speed as we call it in the Fpv world).

2. battery options is a secondary matter.... with a crap efficient setup... and good battery options... like a cow eating grass on a tree.
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Old May 14, 2015, 02:14 PM
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Quote:
Originally Posted by Hobbyzone.Au View Post
like a cow eating grass on a tree.
I've actally seen a cow eating grass on a tree


anyhoo, carrying extra batteries means i have to sacrifice my precious payload and i have a much easier solution. run a super capacitor.

Attach the capacitor directly to the battery so its always charged. if its not in use, it doesn't eat up the batts power so yeah.

this is some 150 grams compared to 700 6s lipo. although since capacitors run out fast so it would have boost characteristics (don't know bout u but the thought of having boost on an electric rc plane is just AWESOME!! yeah. but really who needs to be on max thr for long periods of time. this capacitor would give like 5 mins worth then leave for 5 mins then its good for another BOOOSSTT!!

so is this a valid thought or
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Old May 14, 2015, 08:10 PM
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Just wondering why u want to carry extra batts? Or a super cap?

Just run 100% ions. It will suffice, FPV is not a F1 race.
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Old May 15, 2015, 01:22 AM
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Just wondering why u want to carry extra batts? Or a super cap?
for fun while i'm in view range before really taking off to a land far, far away.


do u recon the ranger can carry 40,000mah 4s?
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Old May 15, 2015, 07:26 AM
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Quote:
Originally Posted by Traiden6 View Post
for fun while i'm in view range before really taking off to a land far, far away.


do u recon the ranger can carry 40,000mah 4s?
I know a 4s 34,000mah can fit the fpv ranger ex. Space is your limit. . Probably can squeeze more.
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Old May 15, 2015, 04:57 PM
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I know a 4s 34,000mah can fit the fpv ranger ex. Space is your limit. . Probably can squeeze more.
how are the flight characteristics comparing a heavy load with a light load
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