Additel 672 Replacement Battery 7.4V 1500mAh Li-ion

Additel ADT 672 — 7.4V Li-ion Replacement Battery (9702 / BP7416)

This 7.4V, 1500mAh Li-ion battery replaces the original pack in the Additel 672 and ADT 672 digital pressure calibrator. It powers the display, measurement circuits, and sensor interface during field calibration work. OEM part numbers 9702 and BP7416 both cross to this cell configuration.

• 672 and ADT 672 platform fit: Both variants share the same battery bay geometry, connector pinout, and 7.4V nominal rail. The BMS handshake threshold is identical across the range, so one pack covers both designations without modification.
• Bench tested on actual hardware: We cycled this pack through the 672's sensor initialisation sequence, where the instrument draws a brief current spike to power the pressure module. The BMS held the load without tripping, and the state-of-charge indicator stabilised within two full charge cycles.
• Pre-deployment calibration cycle: After fitting this battery, run a complete calibration cycle through the instrument's menu before taking it to site. The 672 maps battery state during that sequence — skip it and the low-battery warning will trigger early on your first measurement session, even with a full charge.

BMS lockout after the ADT 672 sat unused in a carry case for months

Li-ion cells self-discharge slowly in storage. If the 672 sat unused long enough, the pack voltage can drop below the BMS recovery threshold — typically around 2.5V per cell, or roughly 5.0V across a 7.4V nominal pack. At that point the BMS enters a protection state and the instrument will not power on or accept a charge. Connect the charger and leave it for at least 30–60 minutes without interruption; most chargers apply a trickle current that nudges the pack above the recovery threshold before switching to normal charge rate. If the charging indicator never activates, measure pack voltage directly — anything below 4.8V across the terminals needs a charger with an explicit recovery or "boost" mode.

ADT 672 shuts off during USB data transfer to PC

USB data transfer adds a combined load — the display stays active, the processor runs at full speed, and the USB interface draws current simultaneously. On a partially depleted pack, this combined draw can pull cell voltage low enough to trip the BMS undervoltage cutoff, which looks identical to a normal shutdown. This is not a fault in the battery or the instrument — it is the protection circuit doing its job. Charge the pack to at least 7.2V measured at the terminals before starting any logging or data export session to keep the voltage above the cutoff threshold throughout the transfer.