Profoto B2 Camera Flash Replacement Battery 14.4V 2500mAh

Profoto B2 Camera Flash — 14.4V Li-ion Replacement Battery (100396)

This 14.4V, 2500mAh (36Wh) Li-ion pack is a direct replacement for the Profoto B2 portable strobe. It fits the B2 flash head and is confirmed against OEM part number 100396. Voltage and capacity match the original spec exactly.

• B2 platform compatibility: The B2 flash head draws current in sharp bursts — each full-power shot recharges a capacitor bank, pulling several amps for a fraction of a second. The BMS on this cell is rated for that spike pattern and holds the voltage rail steady across repeated cycles without triggering a protection cutoff mid-session.
• Bench tested on actual hardware: We cycled this cell through sustained full-power sequences on the B2. The BMS handled capacitor recharge current correctly, voltage held within spec across the discharge curve, and no false low-battery flags appeared during the test run.
• First-fit initialisation on the B2: After installing a new cell, power the flash head fully off — not just standby — before firing your first shot. The BMS handshake between the cell and the B2 head completes only from a cold start. Hot-swapping mid-session and firing immediately can leave the BMS in an uninitialised state, causing premature cutoff or erratic output readings.

Flash output stepping down after 10–15 full-power shots

The B2 capacitor bank demands a high recharge current after every full-power pop. When cell voltage sags under that load, the flash head's power management interprets it as a low-battery condition and steps output down to protect the system. This is not a fault with the cell — it's the BMS doing its job. A cell with elevated internal resistance (common in aged packs) sags harder and triggers the step-down sooner. Replacing the cell restores the voltage headroom, and the step-down threshold resets to its correct level.

Recycle time noticeably slower than the original cell

A new Li-ion cell ships partially charged and with slightly higher internal resistance than it will have after conditioning. On the B2, higher resistance means the capacitor bank takes longer to recharge between shots, so recycle time feels sluggish compared to a run-in pack. This improves progressively over the first five full discharge-and-recharge cycles as the electrolyte fully wets the electrode surfaces. Run five complete sessions at normal shooting pace — do not cut cycles short — and recycle time will tighten up to expected spec.