Profoto B10 Replacement Battery 14.4V 2500mAh 100440

Profoto B10 / B10X Series — 14.4V Li-ion Replacement Battery (100440)

This is a 14.4V, 2500mAh (36Wh) Li-ion replacement battery for the Profoto B10, B10 Plus, B10X, and B10X Plus monolight flash units. It slots into the battery compartment on the base of the flash head and powers both the capacitor charging circuit and the onboard electronics. Voltage and form factor match OEM part number 100440.

• B10 and B10X platform compatibility: The B10 and B10X families share the same 14.4V battery rail and connector housing. Both Plus variants use identical battery architecture — the flash head scales capacitor recharge current based on power setting, not battery model.
• Bench tested on actual hardware: We ran this cell through a full B10 charge and fire sequence across multiple power settings. The BMS communicated correctly with the flash head, the charge LED responded normally, and the protection circuit held under sustained high-power capacitor recharge draws.
• Cold-start initialisation on first fit: After fitting this cell in the B10 or B10X, power the flash head fully off before the first shot. The BMS handshake completes correctly only from a cold start — swapping the battery mid-session without a power cycle can cause the head to report a fault state.

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

At full power, the B10's capacitor demands a fast, high-current recharge from the battery after every shot. A cell with elevated internal resistance — whether aged or not yet conditioned — sags under that recharge current, dropping pack voltage temporarily. The flash head monitors pack voltage and steps down output automatically to protect the capacitor and BMS. After five to eight full-power conditioning cycles, internal resistance drops and output stability improves. If stepping persists beyond that, check pack voltage under load — it should hold above 13.2V during recharge.

Recycle time between flashes slower than the original cell

Slower recycle time on a new cell is a resistance issue, not a capacity issue. Fresh Li-ion cells have slightly higher internal resistance before the electrolyte fully settles into the electrode structure. The B10 recharge circuit is current-limited by whatever the pack can deliver without triggering low-voltage cutoff. Run five full-power charge-and-fire cycles to condition the cell — recycle time typically normalises within that window. If it does not improve after conditioning, measure resting voltage after a full charge and confirm it reads at or above 16.6V.