Synergy 2010 Cordless Phone Compatible Battery 2.4V 600mAh

Synergy 2010 / 2020 / 2100 / 2110 Series — 2.4V Ni-MH Replacement Battery

This is a 2.4V, 600mAh Ni-MH replacement battery for Synergy cordless phone handsets across the 2010, 2020, 2100, and 2110 series, plus additional compatible models. It restores power to handsets where the original cell no longer holds a charge. Physical dimensions are 45.00 × 21.00 × 10.00mm — confirm these match your existing pack before installing.

• Multi-model fit across the 2000 and 2100 series: These handsets share the same 2.4V single-cell NiMH architecture and battery bay dimensions, which is why one pack covers the full range. The connector and polarity orientation are identical across all listed models.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a Synergy 2100 handset. The base station accepted the battery without error, and voltage under RF transmit load stayed stable above the handset's low-battery cutoff threshold.
• First charge after installation: After fitting the new battery, seat the handset in the base and leave it for a full 16 hours before first use. NiMH cells ship partially discharged, and a slow first charge lets the pack reach rated capacity — skipping this step shortens cycle life.

Talk time shorter than expected after the first few charges

NiMH cells don't deliver rated capacity straight out of the box. Fresh cells typically need three to five full charge-discharge cycles before the chemistry reaches its stated 600mAh. If talk time feels short in the first week, that's normal cell conditioning — not a fault. Run the handset down fully, then charge completely for at least three consecutive cycles and talk time will stabilise.

Base station showing a charging error or no-charge light after swap

Batteries that have sat in storage for months can drop to a voltage the base station's charge controller won't accept. The base reads the incoming voltage as too low and refuses to begin the charge cycle. Remove the handset, leave the battery installed, and let it sit at room temperature for 30 minutes — this allows the cell to recover a small amount of resting voltage. Re-seat the handset firmly and the base should recognise the pack and begin charging normally; look for a steady charge indicator, which appears when the cell voltage clears roughly 1.9V.