Nikon EN-EL3 D100 D50 Replacement Battery 7.4V 1300mAh

NiKon D100 / D50 / D70 Series — 7.4V Li-ion Replacement Battery (EN-EL3 / EN-EL3a)

This is a 7.4V, 1300mAh Li-ion replacement for the NiKon EN-EL3 and EN-EL3a cells. It fits the NiKon D100, D100 SLR, D50, and D70 DSLRs. The cell powers the imaging sensor, autofocus motor, LCD, and all onboard electronics during shooting.

• D100, D50, and D70 compatibility: These three bodies share the same EN-EL3 battery bay, lock-tab geometry, and 7.4V power rail. The BMS in each body reads cell voltage through the same contact set, so one cell fits all three without modification.
• Bench tested on actual hardware: We ran this cell in a D100 body through full charge and discharge cycles. The BMS accepted the cell, battery-remaining display updated across charge states, and the shutter, mirror, and LCD drew current without triggering low-voltage cutoff at normal operating temperatures.
• First-use charge cycle on DSLR bodies: Insert the cell and charge it fully inside the camera body or OEM charger before your first shoot. Some NiKon BMS firmware maps its battery-remaining indicator against a discharge curve it only calibrates on the first full cycle — skipping this step causes erratic percentage readings.

Why the D100 battery-remaining display jumps erratically with a new cell

The D100 does not measure coulombs directly. It infers remaining charge by mapping cell voltage against a stored discharge curve. A new Li-ion cell has a slightly different internal resistance profile than an aged OEM cell, so the body's voltage thresholds land at unexpected points on that map. This causes the indicator to jump — showing 80%, then 40%, then 60% within a few frames. One full charge-discharge cycle inside the body lets the BMS re-anchor its readings to the new cell's actual curve.

Camera shows dead-battery icon immediately after inserting a fully charged replacement

This happens when the cell's resting voltage sits just below the D100's wake-up threshold after shipping or storage. The body reads the surface voltage on insertion — if it's under roughly 7.0V, it flags a dead cell before attempting to draw any current. Remove the battery, place it in the OEM charger for a minimum 15-minute topped-up charge, then reinsert. That pushes resting voltage above the wake-up threshold and the body will power on normally.