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Author Topic: At what voltage do I land my Heli with LiPo batteries???  (Read 233 times)
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MojoMaestro
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« on: October 30, 2009, 03:18:28 PM »


Hey guys,

 Big Mega Super Important question Huh?, in multiple cells LiPo when should I land my Heli.

i.e. >  There is a led on the monitor.
         above 11,0V its lighting blue
         10,0-11,0V its blinking blue
         under 10,0V its lighting red
         under 9,8V its beeping and blinking red.
(that's a battery monitor for 3s)

Is that correct , what's the limit for 3S,4S,5S & 6S.
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HandHeld Heli , Falcon 3D 400, EXI 450 CF pro, EXI 500 CF.
mckrackin
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« Reply #1 on: October 30, 2009, 09:48:42 PM »

Try to stay over 3.4 volts per cell.
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dditch66
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« Reply #2 on: October 31, 2009, 08:40:05 AM »

I've found that it's not straight forward to coorelate voltage cut off to amount depletd.
Different battery packs have different IR values (Internal resistance) thus, they will drop voltage under load at different values for different packs.
Cheaper packs tend to have HIGHER IR and will drop MORE voltage under load thus showing up RED sooner.
Better packs tend to have LOWER IR and will drop LESS voltage under load and thus showing up RED later.

There is a wide opinion on where the voltage should be at during load when you land but that voltage is skewed by the IR of the pack. 

If you have a computer charger, you can charge it back up and see how many mAh you put back into it then go from there.

Just as it turns red is probably a good point to stop.
As you spool down to where the motor is off, if it probably will jump up to blue. But taht's just showing you the No Load voltage and most ESC and Lipo alarms are for LOADED voltage.
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Vigilnte
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« Reply #3 on: October 31, 2009, 09:19:57 PM »

I will assume you all are speaking about the Maxpro Lipo monitor?  Do you all or anyone you know use them? I've thought about mounting one on my heli.  They work well?

Q
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Blueray 450 w/adamantium head+tail with a touch of voodoo for no crash luck. HBFP (beater heli)
MojoMaestro
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« Reply #4 on: November 01, 2009, 08:34:50 PM »

Thnx  Sure I ll   use my computer charger to monitor that .Smiley
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canewalker
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« Reply #5 on: November 01, 2009, 10:05:11 PM »

I bought one of those low voltage alarms and hooked it up to one battery and the thing finally tripped the alarm as I was RAPIDLY "auto rotating" to the ground.   Angry
A POS is what I had bought!!!   Angry

I put my LED voltage meter on another battery that caused me to crash because the voltage dropped so low that the servos started cycling through their arc's and I couldn't stop them. I had power to the motor still but, the servos were on vacation!

My LED voltage meter read 9.8 volts on that battery. From this number I'm assuming that's a bad amount of voltage to be attempting to fly with.   Undecided
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to-fast-to-new
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« Reply #6 on: November 01, 2009, 10:53:16 PM »

I have a maxpro batt Monitor & detector LCD-6 and it works pretty well, it always let me know when my batt was low. I still have it but no longer uses it since I use the timer on my dx6i. But I do use the detector too check my batt voltage after every flight...
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belt-cp, exi 450v2 x 3
mckrackin
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« Reply #7 on: November 02, 2009, 05:21:43 AM »

Personally,I can notice a small loss of tail authority and that tells me it's time to reign it in.
My voltage is almost always 22.275 or somewhere very close when I quit.
Of course that's  a 6S.
My 3S packs come down very similar.About 11.1 volts.

I have been known to fly a 6S pack down to 18.5 volts a few times and have to drag it back,barely above the grass.I put 2540mA back in a 2500mAh battery.Bad McKrackin!No...No

Now I try to observe the 80% rule.
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to-fast-to-new
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« Reply #8 on: November 02, 2009, 05:56:22 AM »

I use to do that all the time, fly until I notice a power drop, sometimes I still forget to start my timer and revert back to flying until I get that power drop. But I'm trying to discipline myself for the health of my batteries. 
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belt-cp, exi 450v2 x 3
WC_WICKEDCLOWN
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« Reply #9 on: November 03, 2009, 11:46:48 AM »

best time to land your heli is when the battery goes dead    lol joking of coarse
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MojoMaestro
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« Reply #10 on: November 04, 2009, 02:35:07 PM »

 Ok ,so that 80% rule on a 6S 22.2V means 17.76V, oouch! Huh?
That s where if ur 18.5V is dangerous.
22.2V / 85% = 18.87 V  <<< Is that a better option?

Well then to get more flight time can i exced 3000Mah batteries on my 500,
like a 4000Mah or 5000Mah??

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mckrackin
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« Reply #11 on: November 04, 2009, 03:30:45 PM »

3000mAh is about as heavy as you can go for a 500 size heli.

And the 80% rule applies to the capacity(mAh),not the voltage.
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Beachcomber
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« Reply #12 on: November 06, 2009, 08:32:00 PM »

Mojo,
Sounds like I have the same on-board voltage monitor that you have.  I have been landing as soon as I first see the red light (means my 3S is down to 10 volts under load) and find I usually put back very close to 80% of the mAH capacity back into the battery with charger.  Good not to go below 10 V under load.  But as dditch says, it can depend on your battery.
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MojoMaestro
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« Reply #13 on: November 07, 2009, 01:54:39 AM »

 Thnx guys,

 I will go under 10Volts & nor under 80%,  for sure I won't trust the BEEP on those
lil alarm things. Actualy, I'll just remove them.
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HandHeld Heli , Falcon 3D 400, EXI 450 CF pro, EXI 500 CF.
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