GE 28115FE1 Replacement Battery 3.7V 500mAh Li-ion

GE 28115FE1 Series — 3.7V Li-ion Replacement Battery (5-2762)

This is a 3.7V, 500mAh Li-ion replacement battery for GE cordless phone handsets. It fits the 28115FE1, 28115FE1-A, 28106FE1, 28118FE1, and nine additional models in the same series. Dimensions are 43 × 28 × 4mm — match these against your original cell before ordering.

• Multi-model fit across the GE 28100 series: These handsets share a common 3.7V Li-ion cell format and connector. The BMS in each handset accepts the same charge curve, so one cell covers the full range of compatible models without modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on a GE series handset. The BMS accepted the cell immediately, reported correct voltage at the base station, and the charging LED responded within the first 30 seconds of seating.
• First-charge protocol for Li-ion handsets: Place the handset in the base immediately after installation and leave it for a full charge cycle before making calls. Li-ion cells shipped in storage-state charge may read falsely low on the handset's battery indicator for the first cycle — a full charge corrects the calibration.

Talk time shorter than rated after swapping the battery

A new Li-ion cell arrives partially discharged from storage, and the handset's fuel gauge calibrates against the first full cycle. If you pull the handset off the base before that first cycle completes, the gauge starts from a skewed baseline and will read capacity as lower than it actually is. Run two full charge-to-use-to-depletion cycles and the reported capacity will align with the rated 500mAh. If it still reads short after three cycles, check the base contacts for oxidation — poor contact limits charge current and the cell never reaches full voltage.

Base station shows no charge light after installing new battery

Li-ion cells stored below the base station's detection threshold — typically under 3.0V — will not trigger the charging circuit. The base interprets a deeply discharged cell as no battery present. Connect the handset to a USB-compatible Li-ion charger at 5V for 10–15 minutes to bring the cell above the detection floor, then reseat it in the base. Once the base sees voltage in the accepted range, the charge LED activates and the normal charge cycle resumes.