POWER-FENG C21N1347 37Wh 7.6V Li-polymer battery

37 Wh 7.6 V Li-polymer replacement battery

The POWER-FENG C21N1347 is a 37 Wh lithium-polymer pack rated at 7.6 V and 4775 mAh. It replaces the original C21N1347 cell in a wide range of Asus notebooks including the X554L, X555L, X555LB, X555LN, X555LD and related K555, F555, A555, VM590, FL5500, FL5600, FL5800, W519, W509, R556, R557 and Y583 series. Buyers who need a different voltage, a higher capacity or a battery for a non-listed model cannot use this part.

Sustained discharge and thermal behaviour

Lithium-polymer chemistry delivers a steady voltage curve through the discharge cycle, so the notebook sees consistent power during long work sessions rather than a sharp drop-off near empty. The flat pack construction spreads heat across a larger surface area, helping the cell stay within safe temperature limits under continuous load. Systems that demand peak current spikes well above the rated capacity may still trigger protective shutdown.

37 Wh capacity decides fit

The 37 Wh / 4775 mAh rating is the single figure that determines whether this battery restores the original runtime for the supported Asus models. A lower-capacity cell would cut usable time, while a higher-capacity unit would not fit the chassis or connector layout. Verify the 37 Wh specification against the original part number before ordering.