Walker Clarity C4105 Cordless Phone Replacement Battery 3.6V 700mAh

Walker Clarity C4105 / C4205 / C4210 Series — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH rechargeable battery for Walker Clarity cordless phone handsets, including the C4105, C4205, and C4210 series. It slots into the handset battery compartment and restores cordless talk capability when the original cell has degraded. Capacity is 2.52Wh — matched to the original specification.

• C4105 / C4205 / C4210 platform fit: These models share the same 3.6V single-cell NiMH pack format, physical footprint (46 × 31 × 10.50mm), and connector orientation. One SKU covers all three handsets because the base station charging circuit runs the same 3.6V trickle profile across the range.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench. The NiMH cells accepted the base station's trickle charge without thermal event, and the BMS held voltage within the handset's operating window across multiple cycles.
• First-charge protocol for NiMH cordless handsets: After installing this battery, seat the handset in the base and leave it for a full 16 hours before use. NiMH cells shipped in storage state need a slow initial charge to reach rated capacity — pulling the handset off the base early will leave the pack undercharged and shorten apparent talk time.

Base station charge light stays off or shows error after installing this battery

NiMH packs lose voltage during warehouse storage. If the resting voltage drops far enough, the base station's charge acceptance circuit may not recognise the pack as a valid cell and will refuse to start the charge cycle. This is a voltage threshold issue, not a fault with the battery or base. Some Clarity base stations require the pack to present above approximately 3.0V before the charge LED activates. If the light stays off, remove the handset, wait 60 seconds, reseat it firmly, and check that the contacts on both the handset and cradle are clean and making full contact.

Range drops noticeably when the handset moves away from the base

DECT handsets draw a brief current spike each time the RF module transmits. A partially conditioned NiMH pack has higher internal resistance than a fully cycled one, which causes voltage to sag under that transmit load. The handset interprets the sag as low battery and reduces transmit power, which cuts range. This clears up after three to five full charge and discharge cycles, as internal resistance drops. Run the handset down to the low-battery warning, return it to the base for a full charge, and repeat — range should stabilise by cycle four.