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Old Aug 26, 2011, 09:55 PM
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Madhawk 300 won't lift off

I have had my madhawk 300 for a week and flown it four times. each time the battery wouldtake about 1 1/2 hr to charge. now it only takes 15 minutes to charge and the heli won't lift off.

Also when i measure the voltage on the battery it reads 8 volts. This seems odd as it charges in 15 minutes now so how is it fully charged?
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Old Aug 26, 2011, 10:25 PM
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A fully charged 2 cell should read 8.3 - 8.4v. When are you measuring voltage, before or after attempted flights?
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Old Aug 27, 2011, 12:54 PM
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I am measuring before flight. What I don't understand is why it is only taking 15 minutes to charge. and why the heli won't lift off if it is fully charged.
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Old Aug 27, 2011, 03:27 PM
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If it reads 8.0v it is not fully charged. That heli is very heavy and the tail drive system draws lots of amps.
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Old Aug 27, 2011, 04:21 PM
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Quote:
Originally Posted by Firstheli View Post
I have had my madhawk 300 for a week and flown it four times. each time the battery wouldtake about 1 1/2 hr to charge. now it only takes 15 minutes to charge and the heli won't lift off.

Also when i measure the voltage on the battery it reads 8 volts. This seems odd as it charges in 15 minutes now so how is it fully charged?
How low did you fly the battery? Lipo batteries cannot be drained all the way down or they will be permanently damaged and will no longer take a charge properly. Most abide by the 80% rule and always leave 20% capacity in the pack or roughly 7.4 volts left after a full flight for a 2 cell pack like yours.
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Old Aug 28, 2011, 02:12 AM
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As of having this heli myself make sure the gears are aligned and when you move the main gear (the large one in the middle) make sure the rotors move with it. if not that then you might need to buy a new battery since it dose not have enough power.

please add more info ie. dose not lift off but rotor moves. rotors dont move motor spinning. things like that so we can help you better.
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Old Aug 28, 2011, 03:11 AM
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Suggest you check battery voltages before & after trying take off. It seems battery lost charge & damaged due to irreversible chemical reaction. Try new battery & see if charger work. If new battery cannot take off helicopter & take 15 min to full charge, it may be your stock charger problem but it's rare.
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Old Aug 28, 2011, 08:30 AM
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The motors spins and it does lift off about an inch or so but that's it. The main gear does mother seem to b any tighter or looser then when I first got it.

The voltage after flight is 7.95

:
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Old Aug 28, 2011, 08:57 AM
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Originally Posted by Firstheli View Post
The motors spins and it does lift off about an inch or so but that's it. The main gear does mother seem to b any tighter or looser then when I first got it.

The voltage after flight is 7.95

:
You don't have enough voltage to fly. Your battery should be 8.4V when full and roughly 7.4-7.7V after a 6-8 minute flight, so your voltage readings are what I would expect AFTER a full flight.

Either the battery has been over discharged and is ruined or the charger is malfunctioning.
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Old Aug 28, 2011, 10:20 AM
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It's easy to ruin a battery with that heli, due to the high resistance of the tail drive system. But, those basic Walkera balancing chargers are very inaccurate, too.
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Old Aug 28, 2011, 11:01 AM
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O.K. you have battery voltage 8.0v before flight and 7.95v after flight. How long is your flight test. If you tried to take off heli for a while, charged battery should drop voltage more than just 0.05v, no matter what is the voltage before, as longer as battery volatge is above threshold lowest limit and in good condition. It means battery may have no charge at all. If I were you, I will try another new battery /w stcok charger and see the result. Do you have another charger for 2s and test before buying new battery?
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Old Aug 29, 2011, 08:25 PM
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Update: I recharged the battery today and it took longer then 15 minutes and the voltage before flight was 8.4 volts ( I must have miss read it the other day when I saw 8v).

I also tightend up all the screws and adjusted the play between the motor and the main gear. I just tried it and it lifted off. That's all I could do for now because I am in ct with no power and didn't Get out of work in the day light.

I hoping to get time tomorrow to try it in the day light.

Thanks for all the help I really appreciate it.
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Old Aug 30, 2011, 01:43 AM
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right on. glad to hear you get the heli lift off. You just remind me one thing that make sure the battery connector is secured and hooked up properly to battery charger. Any lose or bad connection cause higher resistance contact and develop voltage drop that may interfere the battery charger voltage sensor. keep post and updated your progress.
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