FPV HUB
Advanced search  

News:

Who's Online
  • Dot Guests: 71
  • Dot Hidden: 0
  • Dot Users: 4
  • Dot Users Online:
* Site Sponsor
* Random Gallery Items
BODEGA

Views: 1638
Posted by: COKE32
in: FPV SPAIN
DSCF6004

Views: 1778
Posted by: n00b@FPV
in: Stuff
QUEDADA FPV 020

Views: 1876
Posted by: COKE32
in: FPV SPAIN
IMAG0166

Views: 917
Posted by: Njoro
in: FPV Stuff
* Latest Gallery Items
IMAG0786

Views: 1991
Posted by: Njoro
in: FPV Stuff
Ground Station

Views: 2575
Posted by: Njoro
in: FPV Stuff
IMAG0165

Views: 2439
Posted by: Njoro
in: FPV Stuff
IMAG0161

Views: 1399
Posted by: Njoro
in: FPV Stuff
zeroG Raptor

Views: 1738
Posted by: Njoro
in: FPV Stuff

Author Topic: What is happening to this cell (jumping up and down)  (Read 770 times)

CurryKitten

  • Air Vice-Marshal
  • *
  • Karma: 71
  • Online Online
  • Posts: 3590
  • Brought to you by Google
    • My YouTube page
What is happening to this cell (jumping up and down)
« on: May 05, 2017, 11:47:25 AM »

I got a little 180 2s out to check something and noticed I was getting nothing when I plugged it in (all my lipos go onto storage after they are flown) I plugged it in the charger to check the cell voltage and it beeped and told me "low voltage"

I plugged it into a lipo tester and it told me that cell 2 was on 0.5v...eek, never seen anything that low before, and weird as my lipos all go onto storage charge after I fly them.

I wanted to see what would happen if I put a bit of voltage back in, so put the charger on Nimh mode for a minute, and noticed the voltage instantly jumped to 6.xv - which was weird.  I was starting think I had a dodgy connection somewhere, so put back onto lipo mode and had a look what would happen if I put the lowest possible charge into it.

The result was this -

! No longer available


Very weird jumping up and down.  When I took it off charge 1 minute later, I plugged it back into the lipo tester and every time it cycled around to tell me the cell charge it dropped every time.

Clearly the lipo is toast, and so will be disposed of - but I was interested to know if there was a reason for the voltage jumping back and forth like that, as I suspect it might be useful indication that something very wrong is happening

tim_h

  • Flying officer
  • *
  • Karma: 1
  • Offline Offline
  • Posts: 98
Re: What is happening to this cell (jumping up and down)
« Reply #1 on: May 05, 2017, 12:46:55 PM »

Could be a loose connection / bad solder joint onto one of the balance lead wires perhaps? Assuming the balance plug end is ok.

Using a multimeter you could test the resistance between the main negative  wire and the black balance wire, then test from the main positive wire and the last (third on a 2s) balance lead wire. These should both be a very low resistance, much less than 1ohm, and both readings should be about the same.
Logged

Coyote

  • Admin
  • Marshal of the Royal Air Force
  • *
  • Karma: 313
  • Online Online
  • Posts: 18788
    • My New Blog
Re: What is happening to this cell (jumping up and down)
« Reply #2 on: May 05, 2017, 01:17:13 PM »

Thats normally a bad joint or lead as stated above.
Logged
Education and schoolin is good, but FPV is gooder :)


My Blog
My Youtube
My Vimeo

CurryKitten

  • Air Vice-Marshal
  • *
  • Karma: 71
  • Online Online
  • Posts: 3590
  • Brought to you by Google
    • My YouTube page
Re: What is happening to this cell (jumping up and down)
« Reply #3 on: May 05, 2017, 05:29:52 PM »

Ok, well worth a closer look, so I (carefully) removed the outer layers to look for dodgy connections.  It seemed to look ok, but not having delved inside a lipo, I'm not exactly sure what it should look like.  I took some pics from 2 different angles





The only thing I noted is that there didn't seem to be a metal tag going to the ground like there was on the red/blue wires - but this could be the normal case.

Andy Sayle

  • Wing Commander
  • *
  • Karma: 11
  • Offline Offline
  • Posts: 907
Re: What is happening to this cell (jumping up and down)
« Reply #4 on: May 05, 2017, 09:09:39 PM »

Could be a dodgy balance connector.....
Logged
Duct Tape and a Hammer.  A cure for all known mechanical problems.

Steve W

  • "The Gaffer"
  • Marshal of the Royal Air Force
  • *
  • Karma: 272
  • Offline Offline
  • Posts: 11136
  • ^ not actual size
    • DroneFinder
Re: What is happening to this cell (jumping up and down)
« Reply #5 on: May 06, 2017, 12:04:03 AM »

Not sure I'd trust it in my house tbh

CurryKitten

  • Air Vice-Marshal
  • *
  • Karma: 71
  • Online Online
  • Posts: 3590
  • Brought to you by Google
    • My YouTube page
Re: What is happening to this cell (jumping up and down)
« Reply #6 on: May 06, 2017, 12:12:13 AM »

Me neither Steve - it's sitting in it's own lipo bag waiting to be disposed of now.  I just wanted to check if there was anything obviously wrong in the wiring... the fact that there's nothing obviously wrong makes it all the more dodgier IMO. 

Not sure I'd trust it in my house tbh
 

* Recent Topics
First look/flight/crash of the RunCam Split by iwan_canobi
[Today at 06:11:47 PM]


ISDT FD-100 smart lipo discharger 2-8S lipo up to 80W discharge by SnoozeDoggyDog
[Today at 09:45:33 AM]


AKK Technology Coupon Code Sharing by Dennislee
[Today at 04:42:42 AM]


What arrived today? by beesleyboy
[Yesterday at 08:05:26 PM]


Quanum HT help! by drambuidhe
[Yesterday at 07:38:39 PM]


E.T.s Skywalker Falcon RTL & Loiter test using the Little Pilot Monitor by English Turbines
[Yesterday at 05:20:54 PM]


FrSky S6R rx and integrated stabiliser by CurryKitten
[Yesterday at 12:14:00 PM]


Sharing My Music and Sound FX - Over 1000 Tracks by Eric Matyas
[Yesterday at 01:31:20 AM]


British Championship 2017 by Ratty
[October 17, 2017, 11:58:11 PM]


Hello from Lincolnshire by Ratty
[October 17, 2017, 08:21:08 PM]


Vortecks DIY eBike project by Steve W
[October 17, 2017, 10:29:37 AM]


Flying field near Blackpool, Lytham, Poulton, Fleetwood? by BigT
[October 17, 2017, 10:02:50 AM]


Quarry by Lamaule
[October 16, 2017, 09:48:56 PM]


Chasing planes with the Mavic by English Turbines
[October 16, 2017, 09:06:37 PM]


Review of the Bfight 210 BNF quad by CurryKitten
[October 16, 2017, 05:17:43 PM]

* Keywords
fpvhub  fpv hub
first person view video piloting

rc r/c r.c. model aircraft flight pilot fpv piloting wings fly flying flight fuse fuselage aileron tail pan tilt tx rx vtx rtx receiver transmitter video radio control controlled headtracker fpvuk bfpvmfa fpv uk first person view video piloting fpv servo servos easystar easy star multiplex antenna VR1400 fatshark video goggles 2.4 5.8 1.2 900 ghz mhz uhf panel antenna circular fpv polarised tracker dbi 10mw 100mw 500mw camera osd fpvuk bfpvmfa fpv first person view video piloting downlink ezantenna tracker gps EzOSD current sensor tiny telemetry autopilot ccd gopro kx131 kx171 FY21 FY21A FY21AP II IMU oracle diversity processor video switcher fpvuk bfpvmfa fpv uk first person view video piloting insurance simulator delta wing glider funjet quadcropter helis heli helicopter electric nitro scratchbuild scratch build batteries battery 2s 3s 4s lipo lipos fpvuk first person view video piloting Antenna fpvhub  fpv first person view video piloting rc r/c r.c. model aircraft flight pilot fpv Airframe Artifical Horizon Auto pilot Av AWG AWU Bec Brownout Buddy box C rating CG Circular Polarized Data logger Dbi Dbm Dipole Diversity DVR Easycap EPO EPP Failsafe FM Freshnel zone Frequency Gain Ghz Goggles GPS Ground Station Gyro Head Tracker HD Hz Inverted Vee Jst LC Filter Lipo LUX Mah Mhz Omni OSD Pan Patch Platform Polarization Rssi RTH Servo Spotter Telemetry Tilt Tracker Transmitter TVL Ubec UHF Video Splitter Vrx Vtx Watts Yagi  fpv uk first person view video piloting rc r/c r.c. model aircraft flight pilot fpv

http://www.fpvhub.com/forum/index.php?action=sitemap;xml http://www.fpvhub.com/forum/index.php?action=sitemap http://www.fpvhub.com/forum/index.php?action=sitemap;start=0 http://www.fpvhub.com/forum/index.php?action=sitemap;start=100 http://www.fpvhub.com/forum/index.php?action=sitemap;start=200 http://www.fpvhub.com/forum/index.php?action=sitemap;start=300 http://www.fpvhub.com/forum/index.php?action=sitemap;start=400 http://www.fpvhub.com/forum/index.php?action=sitemap;start=500 http://www.fpvhub.com/forum/index.php?action=sitemap;start=600 http://www.fpvhub.com/forum/index.php?action=sitemap;start=700 http://www.fpvhub.com/forum/index.php?action=sitemap;start=800 http://www.fpvhub.com/forum/index.php?action=sitemap;start=900 http://www.fpvhub.com/forum/index.php?action=sitemap;start=1000 http://www.fpvhub.com/forum/index.php?action=sitemap;start=1100 http://www.fpvhub.com/forum/index.php?action=sitemap;start=1200
* Disclaimer
The content, views and opinions expressed within this forum are those of the authors and do not necessarily reflect the views, official policy or position of FpvHub. However, we reserve the right to remove or edit any content considered inappropriate.