Tether Tools Air Direct 7.2V Replacement Battery 1600mAh

Tether Tools Air Direct — 7.2V Li-ion Replacement Battery

This 7.2V, 1600mAh Li-ion cell replaces the internal battery in the Tether Tools Air Direct wireless tethering and camera control unit. It fits the Air Direct directly and matches the original voltage and capacity spec. Use it as a backup cell during long shoots or to replace a degraded primary battery.

• Air Direct power system: The Air Direct draws from a single Li-ion cell to run its wireless radio, USB tethering bridge, and camera control logic simultaneously. All three loads share the same 7.2V rail, so voltage stability across the discharge curve matters — this cell holds that rail through to the low-voltage cutoff.
• Bench tested on actual hardware: We cycled this cell through the Air Direct's charge and discharge circuit. The BMS accepted the cell without error, completed a full charge cycle cleanly, and the protection circuit triggered correctly at the low-voltage threshold without unexpected cutoff mid-cycle.
• Wireless session charging tip: If you are running the Air Direct tethered to a laptop via USB-C for pass-through power during a shoot, remove the battery first and reinsert it before a standalone session — this forces the BMS to re-read the cell's state of charge and avoids a false low-battery shutdown at the start of the next wireless session.

Why the Air Direct drops its wireless connection when the battery still shows charge

The Air Direct's radio module is the highest-draw component in the unit. When the cell voltage sags under load — even briefly — the radio can lose its connection before the battery indicator reaches zero. This is more common toward the end of a cell's life when internal resistance climbs. A new cell with lower internal resistance holds voltage steadier under the radio's burst draw. If you are seeing intermittent dropouts on a battery that reads partially charged, internal resistance is the likely cause, not remaining capacity.

Air Direct not powering on after the battery has been stored flat

Li-ion cells stored at or near zero volts can drop below the BMS's minimum recovery threshold — typically around 2.5V per cell. The Air Direct's charge circuit may not initiate a charge cycle if the cell voltage is too low on first connect. Place the battery in a compatible external charger that supports trickle or recovery charging to bring the cell voltage above 3V before reinserting into the Air Direct. Once above that threshold, the unit's charge circuit will take over and complete the charge normally.