About this replacement
NiKon Coolpix P1 / S1 Series — 3.7V Li-ion Replacement Battery (EN-EL8)
This is a 3.7V, 650mAh Li-ion replacement for the NiKon EN-EL8 battery. It fits the Coolpix P1, P2, S1, and S2, along with thirteen additional Coolpix models that share the same EN-EL8 form factor and voltage rail. The cell matches OEM dimensions at 46.60 × 35.30 × 5.00mm and drops into any EN-EL8-compatible charger or camera body.
- EN-EL8 platform compatibility: The Coolpix P1, P2, S1, and S2 share a single battery platform — same 3.7V rail, same physical footprint, same connector orientation. NiKon standardised the EN-EL8 across compact Coolpix models released in that generation, so one replacement covers the full range without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge passes on a Coolpix body. The BMS accepted the cell without error flags, held voltage above 3.5V through the discharge curve, and reported capacity within normal tolerance of the OEM cell.
- First-cycle camera body charging: On first install, charge the cell inside the camera body using the OEM charger cable rather than an external bay charger. Some Coolpix BMS firmware requires an in-body charge cycle before it maps the new cell's discharge curve for accurate battery-remaining display.
Why the Coolpix P1 reports a dead battery indicator on a freshly charged replacement cell
The Coolpix P1 uses a voltage-threshold system to estimate remaining charge rather than a fuel-gauge IC. A new replacement cell has a slightly different internal resistance profile than the aged OEM cell the camera learned from, so the voltage readings map differently at rest. The camera can interpret a resting voltage of 3.9–4.0V from a new cell as lower than it actually is during the first few cycles. Running one or two full charge-discharge cycles through the camera body recalibrates the threshold mapping and clears the false low-battery flag.
Battery percentage jumping erratically mid-shoot on the Coolpix display
If the battery indicator skips from 60% to 20% mid-session without warning, the cause is usually the camera's discharge curve model mismatching the new cell's actual output profile. Flash charging draws a sharp current spike that causes a momentary voltage dip — the Coolpix interprets that dip as a lower state of charge and snaps the indicator down. This settles after two or three full cycles as the BMS builds a better picture of the cell's real discharge behaviour. If jumping continues past three cycles, check resting voltage with a multimeter — a fully charged EN-EL8 replacement should read 4.15–4.20V at rest.