Some advice on batteries please.

[Seadweller]

Hello,

I have a DJI f550 that I have been flying for about 8 months now using the Naza v-2, after upgrading from my f440. I have been using turnigy 5000mah 3 cell 11.1v batteries and they have always lasted about 7 to 8 minutes.
The problem is I had a crash last weekend on the remote mud flat I use when a battery became unsecured in the gusty conditions (stupid I know, and I have learned that lesson) It was not too high and landed onto wet sand, breaking a prop and cracking the battery which had detached before it hit the ground, something I have obviously discarded.
Now although it flies perfectly it is eating through batteries. One battery is only lasting 2 minutes in a static hover. I thought it was the dji ground station that I had just installed however after completely unplugging it my battery length is still just a couple of minutes.

Does anyone have any experience of this and can offer some advice or have any ideas where I could seek some.

I balance charge my batteries using the same turnigy accucell 6 that I always have.

Really looking forward to your replies

Alex.

 

[Charles Bruckner]

I am willing to bet one or more of your motors might have been slightly damaged.
it still spins but it uses more current to work causing lower flight times.

When you shut it down does any of the props stop spinning before the others.
Or with the battery removed and manually spinning the prop does it stop quicker than the others.

after flying the craft and shutting down the motors immediately feel the motors in any of them hotter than the others that's also indicator it's using more current.

If I was to trouble shoot it I would attach it to a surface so it could not take off.
Put my Fluke 89 multi-meter in series with the motor controller and power supply and measure
the current or amps and check it that way.

also the motor controller could have been damaged so keep that in mind.
Good luck.

Also I have heard the the NASA V-2 has a crash mode? and needs to be reset via software.
Not too sure about this but I thought I read about it in another post here.

I may be a newby to the hobby but I am not new to failure analysis.

 

[Charles Bruckner]

BTW welcome to the Forum,
I know it has just a few members at the moment but there are some good experienced
pilots and engineers like my self.

 

[Seadweller]

Hi Charles

Thanks for coming back, it is so good knowing you are not alone.

I spun up the motors this afternoon and they all seem to be ok. I measured the temps and they all seemed the same and spun down at the same rate. There does not seem to be any part of it getting really hot so I just do not know where the energy is going. I do not know if maybe I have prematurely harmed my batteries by letting my charger take control of the charging programme, not stopping until they are at 12.60v on a 3 cell. I am at a real loss, any advice would be greatly appreciated.

Alex

 

[Charles Bruckner]

Try a new battery and see if you get your normal run time.
LiPo's are finicky animals and are not forgiving of mistakes.
or if you can borrow a mates battery to test.
Cheers.