About this replacement
Akerstroms 200J / MC98 Transmitters — 2.4V Ni-MH Replacement Battery (940684-000E)
This is a 2.4V, 2000mAh Ni-MH rechargeable battery for Akerstroms 200J and MC98 wireless transmitters used in crane and industrial hoist operations. It replaces OEM part numbers 940684-000E, 940684-000, and 170.2151. Swap it when the original cell no longer holds a charge or refuses to charge at all.
- 200J and MC98 transmitter fit: Both transmitter models run the same 2.4V two-cell Ni-MH pack with the same connector footprint and BMS handshake requirements. One battery covers both units without modification.
- Bench tested on actual hardware: We cycled this cell through full charge and load discharge on a 200J transmitter frame. The BMS accepted the pack without fault codes, and voltage held stable through repeated solenoid activation sequences.
- Monthly charge during idle periods: Crane remotes often sit unused between jobs. Ni-MH cells left uncharged for extended periods self-discharge below recoverable voltage — charge this pack at least once a month during storage to keep the cells above 1.0V per cell.
Solenoid activation causing power dropout on a freshly installed battery
When a crane remote triggers a solenoid or relay, the inrush current spike can briefly exceed what a partially charged or degraded cell can deliver. The BMS interprets this as an unsafe draw event and cuts power to protect the pack. This looks identical to a dead battery but the transmitter will often recover seconds later. Ensure the replacement pack is fully charged before the first use — a cell at storage voltage (roughly 2.2V for a two-cell Ni-MH) does not have the headroom to absorb that inrush peak without tripping the BMS.
Transmitter shows low-battery indicator immediately after installing a new cell
New Ni-MH packs ship at partial storage voltage, not at full charge. The transmitter's voltage monitor reads the resting cell voltage on first boot and flags it as low — this is expected behaviour, not a faulty battery. Connect the pack to the Akerstroms charger before putting the transmitter into service. A full charge cycle brings the pack to approximately 2.8–2.9V resting, which clears the low-battery flag and ensures the transmitter operates within its rated voltage window.