Clarity 74245 Replacement Battery 3.6V 700mAh Ni-MH

Clarity 74245 / C420 / C430 / C435 — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH battery for the Clarity 74245, C420, C430, and C435 cordless handsets. These models share a common battery bay and connector, so one pack covers the full range. Install it when the original battery no longer holds a charge or the handset dies shortly after leaving the base.

• 74245, C420, C430, and C435 compatibility: All four models run on the same 3.6V three-cell NiMH configuration with an identical footprint — 45.90 × 31.20 × 10.70mm — and the same two-pin connector orientation, so this pack seats correctly across the entire lineup without modification.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a Clarity cordless handset. The BMS accepted the charge signal from the base station immediately, and voltage held steady across standby and active call load without sagging below the handset's low-battery cutoff point.
• First-charge protocol for NiMH cordless packs: After installing, place the handset in the base cradle and leave it for a full 16 hours before use. NiMH cells need a slow initial charge to reach rated capacity — cutting it short on the first cycle leaves usable capacity permanently on the table.

Range drops after installing a new NiMH pack

DECT handsets adjust transmit power based on available voltage. A partially conditioned NiMH pack has a shallower voltage curve than a fully cycled one, so the handset reads available power conservatively and pulls back RF output. This is most noticeable in the first few charge-discharge cycles, before the cells reach full capacity. Run three to five complete cycles — full charge from the base, then use until the low-battery indicator trips — and range will recover to the level the original battery delivered.

Handset not pairing with the base after the battery swap

Some Clarity DECT models store pairing data in volatile memory that clears when power is fully removed — which happens the moment you pull the old battery out. If the handset shows "searching" or fails to ring after the swap, the pairing registration has been lost. To re-register, press and hold the Find Handset button on the base for roughly five seconds until the base beeps, then navigate to the handset's menu and select Register or Locate Base. The handset should pair within 60 seconds and return to the home screen.