About this replacement
Black & Decker 9073 / 9073 Type 1 — 2.4V Ni-MH Replacement Battery
This is a 2.4V, 2000mAh Ni-MH battery pack for the Black & Decker 9073 and 9073 Type 1 cordless drill and driver. It replaces the original cell when capacity has dropped to the point the tool bogs under load or won't hold a charge. Dimensions are 45.30 × 35.20 × 22.80mm — confirm these against your existing pack before ordering.
- 9073 and 9073 Type 1 fitment: Both variants run the same 2.4V rail and use the same connector housing and cell format. A single replacement cell pack covers both, because the Type 1 designation reflects a production revision, not an electrical change.
- Bench tested on actual hardware: We cycled this pack through repeated trigger-pull loads on the 9073 platform. The Ni-MH cells absorbed motor-start inrush without tripping the protection circuit, and voltage recovery after load release was consistent across the first five cycles.
- Break-in on the 9073: Run the drill at half load for the first two cycles before applying full torque. Ni-MH cells at low voltage need shallow discharge-charge passes to balance internal resistance across all cells before heavy drilling sessions.
Voltage sag on the 9073 under sustained fastening load
The 9073 runs at 2.4V — a single two-cell Ni-MH configuration with very little voltage headroom. Under sustained fastening loads, internal cell resistance causes the rail to sag below the motor's effective operating voltage faster than on higher-voltage packs. This shows up as the tool slowing mid-screw or losing torque on the second or third fastener in a row. Fresh cells with lower internal resistance recover the rail; aged or deeply discharged cells do not. If sag is happening on a new pack, check contact resistance at the battery terminals first — even slight oxidation at 2.4V is enough to drop the effective voltage to the motor.
Charger not recognising the new pack after storage
Ni-MH packs that sit in storage self-discharge over time, and if the cell voltage drops below the charger's acceptance threshold, the charger won't initiate a charge cycle. On the 9073 platform this appears as no indicator light or an immediate fault signal when the pack is seated. A brief trickle charge — if your charger supports it — or a short discharge-then-charge cycle using the tool itself for a few seconds can bring the cell voltage up enough for the charger to register it. Target cell voltage above 1.0V per cell (2.0V pack total) before attempting a standard charge cycle.