Rigbone71
Hello Everyone! I'm still new to flying & I have a question. (I've searched the forums for answers-)- & what I've gathered is it depends on a lot of different factors. That being said- Im afraid of over- draining my Li-po. Is it okay to fly your plane till it dies? I bought a timer & set it for 8 mins. (I've still to pass my 4 second flight- but anyday now!) Thank you for your input. Im running stock RCPower set up. 2200kv motor, 1600mah 30c lipo, & 40a Skywalker ESC. (2 servos).
Happy Flying!
"Where there is the Will, there IS Way!"
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Wildthing
Usually by the time the plane dies you have gone beyond the recommended low voltage 3.2V per cell. You can buy one of these alarms that plug into the balance plug and it will start beeping when it reaches 3.3V.
https://hobbyking.com/en_us/hobbykingtm-lipoly-low-voltage-alarm-2s-4s.html
Also pick up a cheap voltage tester so you can test before and after a flight. Then once you have done that a few times you will be able to roughly time your flights.

Voltage tester
https://hobbyking.com/en_us/battery-monitor-2-6s.html
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Rigbone71
Ahh that is exactly the info I was needing! Thank you Wildthing! I especially appreciate the links! This is one of the friendliest forums i've visited!
"Where there is the Will, there IS Way!"
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Wildthing
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Ahh that is exactly the info I was needing! Thank you Wildthing! I especially appreciate the links! This is one of the friendliest forums i've visited!

Glad I could help. once you have done this a few times then you can set your timer on the tx (if yours has it). Keep in mind the length of your flight will also depend how hard you fly each time out.
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Airforce101
I usually don't get 8 minutes out of a 2200mAh, more like 5-6 minute flights...

I have one of those voltage checkers and for each plane I have, I roughly know (by measuring cell voltage after each flight) the flight time. It is a bit trial and error to get to the sweet spot, but be sure to err on the side of caution: start with short flights and extend flight time if you have mAh's left-over.

Very important: post-flight cell voltage is only a rough indication. A better way is to use a battery charger that tells how many mAh's it has charged into you battery. This should ideally be close to, but less than 80% of your battery's mAh value.

What helps me, is that I can setup my radio's timer to take into account my throttle channel: if I cut the throttle, the timer pauses, if I am at wide-open throttle, it counts down regularly, if I am at 50% throttle, the timer counts down at 50% too (so 1 second on the timer takes 2 seconds in real life), and anything in between.

Some say power consumption is not linear to how hard you push the plane and that is very true, but this setup of linking your timer to your throttle turns out to work very well in practice! (at least it does for me)
My avatar is what I look like after a "landing"...
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JettaManDan
I use the timer on my radio..or I just have a feel for what the time is normally on my planes and land to be safe. Most parkjets of mine are in the 4-5 minute range.
My YouTube Channel - 250+ Video's! http://www.youtube.com/jettamandan09

I'm an R/C Junkie! 40+ planes - 12 Heli's - 6 multirotors - and ground vehicles galore! I've got issues.
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Wildthing
Quote:
I usually don't get 8 minutes out of a 2200mAh, more like 5-6 minute flights...

I have one of those voltage checkers and for each plane I have, I roughly know (by measuring cell voltage after each flight) the flight time. It is a bit trial and error to get to the sweet spot, but be sure to err on the side of caution: start with short flights and extend flight time if you have mAh's left-over.

Very important: post-flight cell voltage is only a rough indication. A better way is to use a battery charger that tells how many mAh's it has charged into you battery. This should ideally be close to, but less than 80% of your battery's mAh value.

What helps me, is that I can setup my radio's timer to take into account my throttle channel: if I cut the throttle, the timer pauses, if I am at wide-open throttle, it counts down regularly, if I am at 50% throttle, the timer counts down at 50% too (so 1 second on the timer takes 2 seconds in real life), and anything in between.

Some say power consumption is not linear to how hard you push the plane and that is very true, but this setup of linking your timer to your throttle turns out to work very well in practice! (at least it does for me)

That's kind of cool having the timer linked to the throttle
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Airforce101
My radio runs a copy of er9x, I think OpenTx has the feature too.
My avatar is what I look like after a "landing"...
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Rigbone71
Wow! I started off this thread thinking it was a dumb question- and I'm VERY glad I asked! Ill have to check my transmitter for a timer! Thanx for your input & knowledge!
"Where there is the Will, there IS Way!"
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Wildthing
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Wow! I started off this thread thinking it was a dumb question- and I'm VERY glad I asked! Ill have to check my transmitter for a timer! Thanx for your input & knowledge!

What TX do you have? More then likely there will be someone on this forum that can answer all your questions.
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pileit1
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Wow! I started off this thread thinking it was a dumb question- and I'm VERY glad I asked! Ill have to check my transmitter for a timer! Thanx for your input & knowledge!

The only dumb question is one to which you already know the answer.
Welcome to RCPowers. There are a ton of great people here and a great wealth of knowledge and information. Centuries of RC experience I dare say. We also like to engage in a bit of good-natured ribbing at times.
Just another day in paradise!
Any day above ground is a GOOD day.
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drive and air smash
Usually on brand new planes, I will fly for 3 minutes at a time. I will then check the voltage of the battery and decide if I would be running it too close or if I can go back up. Generally, I like run my batteries to 3.7 volts per cell. That being said, I have never gotten a park flyer over 5 minutes. They are alot like SUV's, giant, heavy, gas guzzling machines (because they need alot of throttle to keep them up). It is good to know these things and ask questions. When I first started, I cannot tell you the countless times I put batteries into low voltage mode. It is never fun plugging in a NIMH charger into a LIPO to try to take it out .
When life gives you lemons you make grape juice... then everyone stands back and wonders how you did it .

Check out my YouTube Channel!
https://www.youtube.com/channel/UCCdMYt3mq1eoooP7yqg1YJw
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Baufritz96
I have the throttle timer that Airforce101 described, and also a voltage sensor with telemetry that sends the voltage down to my transmitter. If I drain the battery faster than normal (flying in high winds, power tests etc.), my Taranis lets me know.
Build it, fly it, crash it, build another.
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Airforce101
I should get one of those voltage telemetry thingies too, I already have FrSky telemetry capable Tx & Rx. Ohhh, if only I had the money, time, ...?
My avatar is what I look like after a "landing"...
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Rigbone71
Well i've checked every option on my tx, alas no timer! I really like your approach Drive and Air Smash- (till i can budget a voltage moniter)- I now have a starting point & can grow from there. For future reference, what kind of tx do you have Baufritz96, & did you have to purchase a particular sensor separately? Im grateful for the ideas & knowledge! Thanx all!
"Where there is the Will, there IS Way!"
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