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zzonie77
09-25-2005, 11:09 PM
I have several of these 650 3 cell batteries I got last January and February really cheap ($10 each).
I haven't used them in 4 months. They were stored fully charged. They
still read 11.7 to 11.8 V.
I tested all of them today on 2 different ESC's on a 300 sized motor
(300 XT Aurora) that pulls 4 A as propped. The results are all the same:

After going to full throttle I get a 4 A reading that falls off quickly to
2.5 - 3.0 A (in 10 seconds), at which point the motor varies noticeably
in RPM. The waffling sound/pitch of the motor is giving out a 2 per
second beat/tune. I don't like this kind of music.

The motor and ESC's work great on my other batteries (Polyquest,
Kokam, and Max Amps} so it must be a battery problem.

I know they were dirt cheap so it's no big deal if they're headed for the garbage. I got about 25 flights out of each one.

I just wondered if anyone else has seen this kind of stuff? Comments?
:confused:

Red Scholefield
09-26-2005, 01:06 AM
There have been a lot of changes in LiPo technolgy since you bought these packs. It is a good chance that they cannot support a 6C discharge as your experience indicates.

Matt Kirsch
09-26-2005, 05:06 PM
To expand on Red's comments, these packs may not have been able to support a 6C discharge right from the get-go. After 25 flights, the mild abuse they were probably receiving took its toll. The damaged cells degraded while they sat.

You probably would've noticed this problem much sooner if you had continued using the packs.

REDNECK FLYER
09-26-2005, 07:23 PM
is there any such thing li-pos "leveling off"

zzonie77
09-26-2005, 09:19 PM
Matt & Red ....

Thanks for the info !

The vendor has just responded to the problem and will replace them. He wants to examine them. That sounds fair enough. I'll post his findings when available. Also, a friend is reporting an identical problem with the same LiPo.

Rus