Sagem DCP 12-300 Replacement Battery 2.4V 500mAh Ni-MH

Sagem DCP 12-300 / DCP 21-300 / DCP 22-300 — 2.4V Ni-MH Replacement Battery

This is a 2.4V, 500mAh Ni-MH replacement battery for the Sagem DCP 12-300, DCP 21-300, and DCP 22-300 cordless phone handsets. It slots directly into the handset battery compartment and restores power to handsets that no longer hold a usable charge. Dimensions are 35.00 × 33.00 × 7.00mm — confirm these against your existing cell before ordering.

• DCP 12-300, DCP 21-300, DCP 22-300 compatibility: These three Sagem handsets share the same 2.4V two-cell Ni-MH pack format with identical connector orientation and physical footprint, which is why one battery covers all three models.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Ni-MH compatible charger and confirmed the cells accept current correctly and the voltage rises through the expected charge curve without flattening early.
• First-charge protocol for Ni-MH handsets: After installing, seat the handset in the base for a full 16 hours before making any calls — Ni-MH cells in cordless phones need this slow initial charge to reach rated capacity and set the base station's charge termination logic correctly.

Talk time shorter than original battery after replacement

New Ni-MH cells often deliver noticeably less talk time for the first three to five charge cycles. This happens because the crystalline structure inside fresh Ni-MH cells hasn't fully formed yet, so usable capacity starts below the rated 500mAh and climbs with each full cycle. Run the handset until the low-battery indicator triggers, then return it to the base for a full charge — repeat this three to five times. By cycle five, capacity should be at or close to the rated 500mAh.

Base station shows no charge light or error after battery swap

If the base station's charge indicator doesn't light up after installing a new battery, the pack voltage is likely below the threshold the base uses to detect a valid cell — common after storage. Remove the handset, wait 10 seconds, and reseat it firmly so the charge contacts are fully engaged. If the light still doesn't come on, place the handset in the base and leave it for 30 minutes before checking again — the base needs to see a minimum voltage rise before it confirms a charge cycle is underway. A resting voltage below approximately 2.0V on a fresh Ni-MH pack is normal and should recover within the first charge.