[NSRCA-discussion] Battery going bad?

[Dave Harmon]

Bob.you might note the internal resistance of each cell after the end of the
charge cycle.

I had something similar happen to me a couple of weeks ago..unfortunately.I
had turned off the logs so I can't say for sure what happened.but the motor
just didn't have enough power to pull much of a vertical climb..I tried it
twice and it did the same thing so I went home rather than risk anything.

I don't know what happened..the same pack and motor perform as usual
yesterday and the day before..but.I did notice that the IR is climbiong on
all cells.

They are approaching 5miliohms now.

 

Dave Harmon

NSRCA 586

K6XYZ[at]sbcglobal[dot]net

Sperry, Ok.

 

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Peter Vogel
Sent: Monday, September 17, 2012 3:34 PM
To: Bob Kane; General pattern discussion
Subject: Re: [NSRCA-discussion] Battery going bad?

 

Sounds like at least one cell is dropping significantly under high current
loads.

 

Peter+

On Mon, Sep 17, 2012 at 1:32 PM, Bob Kane <getterflash at yahoo.com> wrote:

I had something happen Saturday that is new for me . . . .   I was going to
put up a flight with my 62" Osiris for a club airshow, I advanced the
throttle to take off, the plane accelerated, then the motor quit.  The
Castle Controller was emitting two beeps, indicating a low voltage error.
One of the club members had a meter that measures individual cell voltages
and everything looked OK.  I used another pack to put up a flight with no
issues.

 

When I got home I discharged the suspect pack and recharged it.  I flew it
yesterday and it seemed to work OK.  I was practicing(!) some maneuvers
repeatedly and the pack quit unexpectedly again, but it may have been my
fault for not paying attention to the flight time.

 

Is this a sign of pending failure?  The pack has maybe 30 cycles on it.  I
have had other packs get puffy and weak but this pack is rock solid.   The
pack is a Rhino 5S 5000mAH 25C pack.

 

Bob Kane
getterflash at yahoo.com


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Director, Fixed Wing Flight Training

Santa Clara County Model Aircraft Skypark

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