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Old Aug 30, 2012, 08:39 AM
Registered User
kryptoknight's Avatar
Canada, MB, Winnipeg
Joined Aug 2011
257 Posts
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Is my Lipo pack already done?

I have 2 GEN ACE 4000mAh 3S lipo that gives my DJi NAZA a short flight of 2 mins and 5 mins on a fully balanced charged condition. My quadcopter only weighs 1200grams. I checked the voltages on my ACCUCELL6 during charging and it reads 11.6 volts. This was after my quadcopter flashed the low batt protection lights and descended from hovering. I checked the voltages reading on each cells during discharge mode and it reads :

discharge voltage @ 9V discharge curent @1A
status - discharge current@ .5A 11.05V
status - 3.68V - 3.71V - 3.68V

I only used these 2 packs for about 15-20 times but I was using cheap IMAX charger rated at 500mA. There was a time when I fully charged these packs and left it sitting for more than 6 months. Is it enough to kill it?
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Old Aug 30, 2012, 10:53 AM
Southern Pride
everydayflyer's Avatar
Haralson County GA. USA
Joined Oct 2004
34,839 Posts
My LiPolys are at full charge for hours only , not days,weeks or months.

Never fly to LVC unless the ESC can be programed to a LVC of 3.5 V.

Each cell should be at or above 3.7 volts after a 5 min. rest following a flight.

Quote:
gives my DJi NAZA a short flight of 2 mins and 5 mins on a fully balanced charged condition.
Sounds like two flights on a single charge. Beaware that some ESCs use a LVC based on the intial voltage at connection time. A flight then disconnecting then reconnecting tjhe LiPoly will cause the LVC to be way to low , even worse that most are to begin with.


Some (to many) LiPoly manufactire still say that it is OK to discharge a cell down to 3V . Non have ever agreed to replace LiPolys that are damaged by discharging them this deeply.

Charles
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Old Aug 30, 2012, 12:15 PM
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kryptoknight's Avatar
Canada, MB, Winnipeg
Joined Aug 2011
257 Posts
Quote:
Originally Posted by everydayflyer View Post
My LiPolys are at full charge for hours only , not days,weeks or months.

Never fly to LVC unless the ESC can be programed to a LVC of 3.5 V.

Each cell should be at or above 3.7 volts after a 5 min. rest following a flight.



Sounds like two flights on a single charge. Beaware that some ESCs use a LVC based on the intial voltage at connection time. A flight then disconnecting then reconnecting tjhe LiPoly will cause the LVC to be way to low , even worse that most are to begin with.


Some (to many) LiPoly manufactire still say that it is OK to discharge a cell down to 3V . Non have ever agreed to replace LiPolys that are damaged by discharging them this deeply.

Charles
Is it also possible that the internal resistance of my pack is already high even if the voltages reading on each cell reads within 0.02 - 0.04V range?
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Old Aug 30, 2012, 01:53 PM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
21,175 Posts
IR and cell balance have no relation to each other. Completely independent. They can be perfectly balanced and have an extremely high IR or low IR.
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