Audioline CDL1800 Replacement Battery 3.6V 700mAh

Audioline CDL1800 — 3.6V Ni-MH Replacement Battery (B3025)

This is a 3.6V, 700mAh Ni-MH replacement battery for the Audioline CDL1800 cordless handset. It slots directly into the handset battery compartment and restores power to the handset for calls and standby. Part number B3025 matches the original factory specification.

• CDL1800 handset compatibility: The CDL1800 handset runs a 3.6V Ni-MH cell at this exact form factor — 45 x 30 x 10mm. The voltage rail and physical connector match the original pack, so the base station charger circuit recognises the new battery without issue.
• Bench tested on actual hardware: We ran this pack through the CDL1800 base station charger and confirmed the BMS accepted the charge cycle without error. Voltage climbed steadily from storage level to full charge without the base triggering a fault light.
• First charge after fitting: Place the handset in the base for a full 16 hours before making your first call. Ni-MH cells in cordless phones need that slow initial charge to reach rated capacity — skipping it leaves you with noticeably less talk time from day one.

Talk time shorter than the original battery after replacement

Ni-MH cells do not deliver full rated capacity straight out of the box. The CDL1800 handset will feel like the new battery underperforms for the first three to five full charge-discharge cycles — this is normal chemistry behaviour, not a fault. Each cycle lets the cell reach a slightly higher usable capacity until it stabilises near the rated 700mAh. Run the handset until the low battery indicator triggers, then return it to the base for a full charge, and repeat for those first few cycles.

Base station not charging — no charge light after fitting new pack

A Ni-MH cell that has sat in storage drops to a low resting voltage, sometimes below the threshold the CDL1800 base expects before starting a charge cycle. If the charge indicator stays off after fitting, remove the handset, wait 30 seconds, and reseat it firmly in the base cradle. If the contact voltage is too low for the base to detect, some units need the handset contacts wiped clean with a dry cloth before the base circuit registers the pack. Check the resting voltage at the battery terminals — it should read at least 3.0V for the base to initiate charging.