About this replacement
Siemens SC240 / SC242 Series — 3.6V Ni-MH Replacement Battery (SC242)
This is a 3.6V, 1500mAh Ni-MH battery for the Siemens 240, 242, SC240, and SC242 cordless DECT phone handsets. It replaces the original pack when the handset no longer holds a charge through a normal day of use. Voltage, connector, and physical dimensions match the factory battery.
- SC240 and SC242 handset fit: These four model variants share the same battery bay geometry, contact orientation, and 3.6V supply rail. One pack covers the full range without modification.
- Bench tested on actual hardware: We cycled this pack through the SC242 handset and confirmed the BMS accepted charge from the base station without fault. Charge current stabilised as expected on the first full cycle.
- First-charge conditioning on NiMH cordless packs: After installing, seat the handset in the base for a continuous 16-hour charge before first use. NiMH cells in cordless phones require a slow initial charge to reach rated capacity — skipping this shortens the usable charge from the first week.
Talk time shorter than original battery after replacement
New NiMH cells ship partially discharged and need three to five full charge-discharge cycles before they reach rated capacity. On cycle one, talk time will be noticeably shorter than the original — this is normal and not a defect. Each full cycle conditions the cell chemistry further. By cycle four or five, capacity stabilises at the rated 1500mAh.
Base station showing no-charge or error light on new pack
Siemens DECT bases check the handset battery voltage before initiating a charge cycle. A new NiMH pack that has sat in storage can drop below the base's acceptance threshold — typically around 3.0V — causing the base to show an error light instead of charging. Remove the handset, wait ten seconds, and reseat it firmly so the contacts are clean and flush. If the error persists, use a known-good USB charger at 5V to apply a trickle charge externally for fifteen minutes to bring the cell voltage above the acceptance floor, then return the handset to the base.