Digitrak DTM300 Mark IV Replacement Battery 14.4V 3300mAh

Digitrak Mark IV / Mark V — 14.4V Ni-MH Replacement Battery (DTM300)

This 14.4V, 3300mAh Ni-MH battery replaces the OEM DTM300 pack in Digitrak Mark IV and Mark V locating receivers, LT Receivers, and Remote Displays. It powers the handheld receiver used to track and locate drilling heads underground during horizontal directional drilling operations. Voltage and capacity match the original specification exactly.

• Mark IV, Mark V, LT, and Remote Display compatibility: These receivers share the same battery bay geometry, connector pinout, and 14.4V supply rail. The BMS handshake protocol is identical across the range, so one pack covers all listed models without modification.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Mark IV receiver. The BMS accepted the pack immediately, reported state-of-charge correctly, and held voltage under the sustained draw of an active locate session without tripping cutoff.
• Mark IV field deployment prep: After fitting a new pack, step through the full receiver calibration sequence in the menu before going underground. The Mark IV maps battery state during calibration — skipping it causes the low-battery warning to fire early on the first active locate session, even with a full charge.

BMS cutoff when the Mark IV receiver initialises its transmitter-tracking signal

When the Mark IV locks onto the sonde signal underground, the receiver draws a short current spike as the tracking circuit initialises. An aged or deeply discharged pack can drop below the BMS cutoff threshold during that spike, shutting the receiver off instantly. This looks like a dead battery even when the charge indicator reads partial. A fresh, fully charged DTM300 replacement handles the spike without voltage sag because all ten cells are at full capacity — internal resistance is low enough to absorb the transient load.

Pack will not charge after months stored in the carry case

Ni-MH cells self-discharge over weeks without use. If the Mark IV receiver sat in a case for several months, the pack may have dropped below the charger's detection threshold — the charger sees too little voltage to confirm a valid cell and refuses to begin the charge cycle. Remove the pack and measure across the terminals with a multimeter. If voltage reads below approximately 10V, the pack has discharged past recovery. At that point, replace the pack — attempting forced recovery on a deeply discharged Ni-MH pack risks cell reversal on the weakest cells in the string.