Charge and sag

Batteries, Chargers, and Battery Management Systems.
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torqueon   1 kW

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Charge and sag

Post by torqueon » Jun 27 2015 9:22pm

Running 32120 headway's cells. They always seem saggy after a full charge and balance at 1st run, let them set for a few hours and next run is great as the day i bought them. Is this the norm for these cells.
Any input appreciated.

Pete

999zip999   100 GW

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Re: Charge and sag

Post by 999zip999 » Jun 27 2015 11:42pm

More info. What controller and motor you using ? BMS ?

torqueon   1 kW

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Re: Charge and sag

Post by torqueon » Jun 28 2015 12:15am

Brushed motor and controller, been using since 2009. Always the same results. Pardon me, a slow learner here !

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BSATOM   1 W

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Re: Charge and sag

Post by BSATOM » Jun 28 2015 12:29am

Most obvious first...Are you describing the peak charging voltage dissipating down to the nominal running voltage?
Most of a cells capacity is delivered at nominal voltage, so fully charged pack showing peak charging voltage will have a tendency to sag down to nominal voltage under load.
So this has been happening all along since 2009? Or is this a new condition? "Been using since 2009. Always the same results" contradicts "next run is great as the day I bought them".
Yeah, full, detailed system hardware info and battery charging/discharging history is needed for a less general response.
Hugo Fugusev...

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dogman dan   100 GW

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Re: Charge and sag

Post by dogman dan » Jun 29 2015 6:22am

Good guess, are they all hot when they come off the charger when you balance them?

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