Board issues when power gets low on battery? Now no pwr to motors. need a workaround...

I have had 2 issues now when my battery runs low. Anyone else had issue?

I have no xbee yet, so I am still old school back and forth into the house to the usb cable...

  for first time night before last, I ran the battery down and got no notification at all from the board.  I figured no big deal, changed the lipo out, proceeded to connect and took off, 2 seconds into the flight the tx seemed to REALLY lag, then she shot into the air about 40 feet and kept going.  I flipped the still untested loiter to see if I could regain any control, lowered throttle and she came sliding in relitavely undamaged thanks to low lying crape myrtle trees, just prop damage. When I brought her into the shop, the radio side of the board would no longer power up. it was odd...


MY SETUP I have 1 power from an esc to my motors (output), I cut and shrinkwrapped the 3 unused wires to get used later.  The jumper clip was clearly in place, and everything powered up just fine until I ran the battery low and the board freaked.  Not the first time I burned a power diode, did it  in one of my quadrinos, so I wired up power from one of the extra escs to the radio for power. Worked fine to power the board.

I checked the  jumper, still there, worked when I powered the radio side so I didn't remove the jumper. Then when I powered up with battery and USB, the jumper smokes a second, I pulled usb and pwr jumper wires from the second esc, and suddenly I had pwr to the input side again... Weird!


So I remounted board to correct another drift issue, went to fly and ran the battery low again, wouldn't take off due to low power.  I brought her in to tune the PIDS, and when I got inside, the motor rail would not power up. 


Is there an issue with low power batteries burning up this board?  Where would I start trying to troubleshoot which is the power diode that is blown, and can I change it?  I have pwr going into the output motor side and nothing.  See photos for my temorary workaround and any suggestions, as its wired now will it work?  I will need to change to a 2 pin on aux 3? far right pin if I want channel 7, but other than that will it work?


In the photo you will see a 3 wire still connected to the motors side, this is to show that it is still connected and I know by testing it on the radio side that there is power there.  The big red and black wire is from second esc and is powering the board.  I lost the original bind clip an the power rail, I rigged a clip, but it makes no difference at all now. 


Thanks guys sorry complicated problem= long post...  Thanks for getting through it... NAd for the help...




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Also board will power up from USB, but that usb is loose already, I expect that too be an issue in the near future.  My xbees will be here in 2days so maybe not:).


All I need to know simplified, if someone could look at the photos, will this be ok as a power workaround for now?

Did you program your ESC's?  Typically they are programmable and can be set to either continue running, reduce power, or shut down based upon a programmable low voltage.  This is done so that the batteries don't get damaged.

No I did not program them, I am not sure, but I believe they are programmed for reduced power.


When battery is low it will drop rpm so I can't take off, but it doesn't act like I discharched battery in other words it doesn't taper down like a low voltage scenario.


Batteries I don't mind so much damaging, but why the weird reaction by the APM. And if not a "diode" or "fuse" what would I try look at on th board? I am all abouut the lesson, and if it is not a diode I would like to know what the proper termilogy is in this regard... Even better would be a what to look for and what to replace?  For know it works though...

If the battery is allowed to deplete a brown out can occur. I know from past experience that a USB can connect a Earth ground loop. If the battery is still connected and touched to a anti static solder iron plugged into a wall outlet, it willl short to the USB with the computer connection.

Wow my typing and grammer is terrible lately. I do know the difference between now and know, but its late and I am typing too fast to notice...

 Interesting, In this case the Apm2 seemed to have issue in the field after I changed the low battery, can low voltage be detrimental to the board if not connected to anything. This was not really a brown out, it was a spaz out... Then the power issues more or less isolated, as I recall the battery I connected was nearly fully charged when I came back in, since it crached on take off due to oddball glitch.  It took off stright up and would not accept control input, at least until I flipped the loiter switch,  it stopped gaining altitude at that point, Flipped back to stable and slid slowly back down to a relatively gentle crash.

For now, will the current configuration work (Power in to radio side) less the common ground you spoke of?  I don't think I will be able to fix whatever blew out, so I hope so!

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