DELL ORIGINAL E6420 Battery

Specification:
Type: Lithium-ion
Voltage: 11.1V or 14.8V (depending on the battery model)
Capacity:
6-cell: Around 48Wh (Watt-hours)
9-cell: Around 85Wh (Watt-hours)
Life Expectancy: Typically around 300-500 charge cycles depending on usage.

Compatible Dell Laptop Models (E6420 Battery)
These models use the same battery types (e.g. T54FJ, M5Y0X, 8858X):
Dell Latitude Series

Latitude E5420
Latitude E5520
Latitude E6420
Latitude E6430
Latitude E6520
Latitude E6530
Latitude E6440 (some overlap with newer battery types)
Latitude E6410 (in some cases, depending on battery connector)
Dell Inspiron Series (select models only)

Inspiron 14R (N4110)
Inspiron 15R (N5110)
Inspiron 17R (N7110)
Dell Vostro Series
Vostro 3450
Vostro 3550
Vostro 3750
Dell Precision Series
Precision M2800 (shares T54FJ battery)