About this replacement
SeaLife Sea Dragon 4500 — 14.8V Li-ion Replacement Battery (SL67510)
This 14.8V, 3000mAh Li-ion battery replaces the original pack in the SeaLife Sea Dragon 4500 underwater flashlight. It fits the SL67510 platform directly and restores full output to the LED driver. Capacity matches the factory spec at 44.4Wh.
- Sea Dragon 4500 compatibility: The SL67510 pack runs four Li-ion cells in series to hit the 14.8V nominal rail the flashlight's LED driver requires. Any pack on this platform must match that series configuration — a lower-voltage pack will cause the driver to throttle output or refuse to fire.
- Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the Sea Dragon 4500 driver circuit. The BMS handled high-current draw on turbo mode without triggering premature cutoff, and cell balance stayed within 30mV across all four cells at end of charge.
- Multi-cell replacement timing: If your Sea Dragon 4500 uses a second battery in rotation, replace both packs from the same production batch. Mixing a fresh pack with a partially degraded one forces the weaker pack to carry uneven load under turbo-mode current draw, accelerating cell damage in the weaker unit.
Why the Sea Dragon 4500 steps down output before the battery indicator reads low
The Sea Dragon 4500's LED driver uses a brownout threshold set above the battery's true cutoff voltage. When cell voltage sags under high current draw — especially on turbo — the driver steps output down to protect the LEDs and the cells before the indicator registers low. This is intentional behaviour in the driver circuit, not a battery fault. If the light dims and then recovers after switching to a lower mode, the cells are approaching their lower voltage limit under load. Charging at that point is the correct response, not continuing on turbo.
Turbo mode runtime dropping sharply after a few dives
Turbo mode on the Sea Dragon 4500 draws significantly more current than standard or medium modes — the cell pack discharges several times faster under that load. If usable turbo sessions are getting shorter across dives, check resting voltage after a full charge. A healthy 14.8V four-cell pack should read between 16.6V and 16.8V fully charged. Anything below 16.2V at rest after a full charge indicates capacity fade, and the pack should be replaced before the next dive.