EnGenius RB-EP802-L Cordless Phone Replacement Battery 3.7V 1800mAh

EnGenius EP-801 / FreeStyl 1 Series — 3.7V Li-ion Replacement Battery (RB-EP802-L)

This is a 3.7V, 1800mAh Li-ion battery that replaces part number RB-EP802-L in the EnGenius EP-801, EP801H, FreeStyl 1, and FreeStyl 1 HC cordless phone handsets. It fits the battery compartment directly and connects to the same 3-pin contact used by the original pack. Capacity is 1800mAh (6.66Wh) — identical to the OEM specification.

• EP-801 and FreeStyl 1 platform compatibility: The EP-801, EP801H, FreeStyl 1, and FreeStyl 1 HC all share the same battery bay geometry, connector pinout, and voltage rail. The handset BMS accepts packs within the same 3.7V nominal Li-ion window, so no firmware or configuration change is needed after swapping.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the EP-801 platform. The BMS accepted the cell without triggering a protection cutoff, and charge termination signalled correctly at full capacity.
• First charge after installation: Place the handset in the base cradle immediately after installing this battery and leave it for a full charge before making calls. Li-ion cells shipped in partial state of charge benefit from a complete first cycle to allow the BMS to calibrate its charge-state register accurately.

Why the FreeStyl 1 handset loses range when the battery is low

The FreeStyl 1 runs its DECT radio transmitter directly off the battery voltage rail. As the cell discharges toward 3.2V, transmit power drops because the RF front end no longer receives its regulated supply voltage. This causes range to shrink noticeably before the handset shows a low-battery indicator. A new cell sitting at full charge — nominally 4.2V — restores the voltage headroom the transmitter needs to maintain full range. If range is still short after swapping, confirm the new pack has completed a full charge cycle in the base.

Base station shows no charge light after battery replacement

Li-ion cells discharged during storage can arrive below the voltage threshold the base charger uses to detect a valid pack. If the base sees a cell below roughly 2.5V, it may not start the charge sequence at all. Remove the handset from the base, wait 10 seconds, then reseat it firmly — the base retries detection on each dock event. If the charge indicator still does not activate, use a USB charger to apply a brief trickle charge directly to the handset before placing it back in the base, which brings the cell above the 2.9V detection floor.