Telstra V580A Cordless Phone Replacement Battery 3.6V 700mAh

Telstra V580A / V580Q — 3.6V Ni-MH Replacement Battery

This is a 3.6V, 700mAh Ni-MH battery for the Telstra V580A and V580Q cordless phone handsets. It slots into the handset battery compartment and restores wireless operation away from the base station. Capacity is sourced from the product specification — 700mAh, 2.52Wh.

• V580A and V580Q compatibility: Both models share the same handset chassis, battery bay dimensions, and 3.6V NiMH charge circuit. The base station applies a trickle charge at the same voltage rail for both variants, so one battery pack covers the full V580 family.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on a NiMH-compatible test rig. The BMS held stable at 3.6V nominal, and the cell accepted trickle charge without thermal anomaly across five consecutive cycles.
• First-charge protocol for NiMH handsets: After installing, seat the handset in the base and leave it there for a full 16 hours before the first call. NiMH cells in cordless phones need a slow initial charge to reach rated capacity — cutting that short means the first few cycles will feel weaker than the rating suggests.

Base station showing no charge light on a new NiMH pack

A NiMH battery sitting in a warehouse for several months will self-discharge below the voltage threshold the base station checks before starting a charge cycle. The V580A base reads cell voltage on contact — if it falls below roughly 3.0V, the charging circuit may not engage and the charge indicator stays dark. Place the handset on the base for 30 minutes anyway. Many base stations will eventually detect the low-voltage pack and initiate a recovery trickle; if the light still does not come on after 30 minutes, remove and re-seat the handset to trigger a fresh contact detection cycle.

Talk time shorter than expected after first few charges

NiMH cells do not ship at full capacity — they need three to five charge-discharge cycles before the electrodes reach their rated output. If talk time feels short in the first week, that is normal cell conditioning, not a fault. Run the handset until it drops the call, then do a full 16-hour charge on the base rather than a top-up. By cycle four or five, capacity should reach the rated 700mAh level.