Graetz SK60 Replacement Battery 6V 2100mAh Ni-MH

Graetz SK60 / TMC4888AF — 6V Ni-MH Replacement Battery

This is a 6V, 2100mAh Ni-MH replacement battery for the Graetz SK60 and TMC4888AF film cameras. It powers the flash circuit, light meter, autofocus, and shutter mechanisms. Use the capacity figure from this listing — 2100mAh — not third-party sources, which vary.

• SK60 and TMC4888AF platform: Both models share the same 6V power rail, cell footprint, and connector orientation. A battery that fits one fits the other without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS accepted the cell without lockout, and flash capacitor recharge current drew consistently without triggering a low-voltage cutoff.
• First-cycle charge tip for film cameras: Run the first full charge through the OEM charger, not a generic multi-chemistry unit. The SK60's charge circuit reads cell resistance during the initial cycle — a mismatched charge rate at first use can cause the camera to underreport remaining capacity on every subsequent cycle.

Flash output dropping mid-shoot on the SK60

The SK60's flash capacitor draws a large current spike to recharge between frames. As the cell voltage sags toward the lower end of the discharge curve, recharge time increases and the capacitor may not reach full charge before the next shot. This produces noticeably dimmer flash output even though the camera shows power remaining. The fix is to check cell voltage under load — if it drops below 5.4V during a flash recharge cycle, the cell is at end of useful discharge and needs recharging.

Battery percentage jumping erratically on the display

Ni-MH cells have a flatter discharge curve than Li-ion, which makes voltage-based fuel gauges less accurate. The SK60's indicator maps voltage thresholds to percentage bands — a new cell with a slightly different internal resistance will shift those thresholds and cause the display to skip levels or drop suddenly. This is a calibration mismatch, not a faulty cell. Run two full charge-discharge cycles through the OEM charger and the indicator will settle to a stable reading.