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Almost lost her... Battery issue/ info
1615 16 2015-5-30
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roy
Second Officer

United States
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Today I almost lost her. I did al my preflight and double check my battery and off I went. I live in an area with tons of trees and rivers. Beautiful area in Virginia. Well I was out at 966 ft., at an altitude of 156 ft. Getting a video of the winding river and marsh. My battery power was still showing 65 % as I was flying then all of a sudden I got a warning that I had 7% battery left and I could see her starting to auto land. Panic set in but instinct took over. I immediately hit the throttle to gain altitude and at the same time full speed ahead towards home. My altitude was now at 416 ft and she was on a steep angle coming down. As luck would have it the night and angle was on my side. The glide path of her comming down barely cleared some close by trees and the top of my neighbors two story house. She came in pretty fast but right at the last moment I hit the throttle and with the
Last amount of juice she had she slowed down and came in for a pretty hard but good landing. No damage at all but a lot of pucker power. I needed to address my shorts after this one. Pulled the battery after plunging into the assistant. All cells looked good showed this was the 45 mission and indicated 87% still good. Baloney. This was the same battery that auto landed a few days ago where I thought I may have not fully charge it. So I charged it up fired her up and hovered and moved around the back yard for a bit. Sure enough the battery did it again showed s high percentage of charge and the dropped right off to almost nothing. Here's one for the ole disposal can.

Any of you have any simular battery issues. I thought the battery getting weak or starting to fail would give us some kind of indication. If I had been flying autonomous as I do a lot of times I would have definitely lost this bird. We have trees here as high as 135ft. And it links like a jungle and just bout as thick.

The battery is the lifeline of these birds. This could cause a lot of losses if this is the normal for aging batteries. What have you guys found. We all need to know the signs of the batteries dropping off.
2015-5-30
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JtrJr-Droner
Second Officer
Flight distance : 4341 ft
United States
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Roy,

Glad you got her back! Sounds like quite an ordeal and it's definitely alarming. I haven't experienced that one, yet! I also do quite a few GS flights. Long ones too. Not sure what to do about it now.

Jerry
2015-5-30
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cob666
lvl.2

Canada
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I've been having issues with batteries lately but they are very inconsistent.  I think I'm having a problem with the battery not seating properly into the Phantom.  Everything looks good for a while but about 5 minutes into a flight I'll notice that the gimbal is very jerky and the phantom drifts excessively when hovering, or the battery will report a very low percentage is left or the Vision App will give me a message that says something like I'm using illegal battery.  But if I land, power cycle the Phantom, remove and then reseat the same battery, I'll have no more issues that flight.

I'm still trying to get to the point where I can recreate the problem consistently but no luck.
2015-5-30
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nrgwise
Second Officer

United States
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This may or may not be relevant, but, I used to get errors reported on two of my batteries fairly consistently.  I posted this before, but the guy at the hobby shop told me to get a circuit writing pen and use it on the tips of the smart contact pins.  I did this - it works very nicely as you have to push the point of the pen to release the stuff and the contact pin fits perfectly.  I did this three or four times letting it dry in between and since then I have not had any battery errors reported.

The pen I got was: CAIG Labs, Inc.  Circuit Writer, precision conductive ink dispenser.
2015-5-30
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JtrJr-Droner
Second Officer
Flight distance : 4341 ft
United States
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nrgwise Posted at 2015-5-31 04:29
This may or may not be relevant, but, I used to get errors reported on two of my batteries fairly co ...

Chris,

Hey I just looked t up on Amazon and here's what I'm getting:

http://www.amazon.com/CircuitWri ... nc.++Circuit+Writer

Is this the right stuff? sounds like some kind of electric glue/solder in the reviews. Just checking, I don't want to glue my spring loaded pins!

Jerry
2015-5-30
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droneflyers.com
Second Officer
Flight distance : 60709 ft
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United States
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I use this - which is different, but should help make sure the contacts remain clean.
http://www.amazon.com/DeoxITGOLD ... tion/dp/B003D8EA7A/
Did the battery test out as having "life" when you do the push button test outside of the quad?
2015-5-30
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nrgwise
Second Officer

United States
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JtrJr-Droner Posted at 2015-5-31 04:38
Chris,

Hey I just looked t up on Amazon and here's what I'm getting:

That looks exactly like the pen that is sitting in front of me now.  As long as it is the CIRCUIT WRITER, it is conductive ink.  Just let it dry fully between dabs.  Oh, and shake the heck out of it first.  There is a ball in the pen, make sure that rattles around for at least 3 to 4 minutes before first use.

From a design standpoint, this is a very weak, yet critical connection.  With vibration and normal wear (they are spring loaded remember) it is very conceivable that momentary loss of contact/continuous intermittent contact of one or both pins could confuse the system greatly since it is a one unit controller.  Just a theory, but explains why a battery will report X% to the control unit but in reality have significantly more than that available.

I recently encountered a similar problem with a machine at work.  The tension system was acting strange and the maintenance guys were stumped.  All systems checked good, yet film kept ripping out due to erratic signals from the tension feedback system.  Long story short, I looked at the system and the tests performed and discovered that there were two sets of contacts that were spring loaded and were to sit on the outer bearing race.  The springs had lost tension over time and the contacts could no longer compensate for variation in diameter or allowable wobble in the shafts.  Very small - we are talking microns - variations caused major problems due to a .39 spring. Luckily this is the only machine we have with this tensioning system in it.  

Just a thought or two.  
2015-5-30
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Oldman
lvl.1

United Kingdom
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I have been very suspicious of these spring loaded contacts, ever since I first got my p2v+ v3 and considered them a bit dodgy.  So I adopted an extra pre-flight routine whereby before leaving home to go flying, I clean the sprung contacts and the two contact plates on the battery with a cotton bud dipped in electrical contact cleaner.  This seems to have worked well and after flying two batteries almost every day for three months, have not had any battery problems (so far, anyway).  One other point, I always remove the battery when not flying, never store or transport the bird with the battery installed as doing so keeps the contact springs compresses which will eventually weaken them and give poor contact.
2015-5-30
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Godfrey
lvl.2

China
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"What have you guys found."

Maybe its not related but I recently landed with the flight app showing 19% remaining charge on the battery when I turned-off the motors, along with the usual app warning and rapid rear red flashing lights.

When I got home and connected the MC to the computer for the routine post flight check, PT2 Assistant reported only 8% remaining charge and it also flashed a "Low Voltage" error message. That's an 11% difference between what the app and the PT2 reported.

The battery had only 17 cycles on it but since the flight was 17:45 minutes long, I am inclined to believe what PT2 reports.  

Lesson for me: The required battery discharge to below 8% every 20 cycles may not be frequent enough to ensure the battery reports correctly its current charge. I used 2 other batteries on this outing but they were spot on with PT2.  Cheers.
2015-5-30
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Gariex
lvl.1

Australia
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Had exactly the same problem over the weekend. I had 3 batteries from a previous p2. When using these batteries on my new p2 I'm getting 6 min, 3 min & 2 min flying time. Go home run the batteries down to 0% to get a good charge. Diagnostic tell me I have good battery life and fully charged.  Back out Sunday, exactly the same thing. Put the new battery in that came with the new p2, all good, 17 min flying time. Wouldn't like to think these batteries are no good after 4 months of non flying. (In Australia I paid $200 each)
2015-5-30
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roy
Second Officer

United States
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To add fuel to the fire DJI says to replace the battery when you get 300 cycles. I've never gotten to a hundred before I have to replace the battery. What's you highest cycles. I've made it to 50 and the battery got puffy and flight time dropped to less than 10 min. Disposed of that $129.00
2015-5-31
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pb05life
lvl.2

United States
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all these battery issues are being caused by the 3.14 firmware. I get the same sudden almost instant drop to 7% sometimes 5% every time I fly now. Mine usually happens around 30%

I have 3 batteries and one is brand new
2015-5-31
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JtrJr-Droner
Second Officer
Flight distance : 4341 ft
United States
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pb05life@gmail. Posted at 2015-5-31 23:37
all these battery issues are being caused by the 3.14 firmware. I get the same sudden almost instant ...

Pb,

Every time I start to think I should upgrade my firmware from 3.12 to 3.14 I see something like you just posted. Guess I'll stay on 3.12 until 3.16 comes out! Thanks for the info.

Jerry
2015-5-31
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Raybro
lvl.4
Flight distance : 11099 ft
United States
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nrgwise Posted at 2015-5-31 04:29
This may or may not be relevant, but, I used to get errors reported on two of my batteries fairly co ...

Very good. I will get one. Thanks Chris.
2015-6-1
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Raybro
lvl.4
Flight distance : 11099 ft
United States
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JtrJr-Droner Posted at 2015-5-31 23:51
Pb,

Every time I start to think I should upgrade my firmware from 3.12 to 3.14 I see something li ...

It's a marketing design to get you to buy the P3...
2015-6-1
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Raybro
lvl.4
Flight distance : 11099 ft
United States
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Roy,
My circumstance was similar on a previous autonomous flight. I was at 75 feet altitude, my battery went to first warning and initiated RTH. The RTH altitude is 150 feet. While in RTH and attempting to gain 75 more feet of altitude it went to critical battery. Luckily the Phantom came into sight and I could see it going into landing mode very close to the top of a tree. I switched to ATTI mode and with throttle full up was able to get it higher over the tree and closer to me. As it was losing power (with full throttle) it did land in my pasture, in a few inches of water. All was fine after a thorough drying.
2015-6-1
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nrgwise
Second Officer

United States
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Raybro Posted at 2015-6-2 04:15
Very good. I will get one. Thanks Chris.

NP  Hope it works as well for you as it has me.
2015-6-1
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