KPN 500 Micro Replacement Battery 3.7V 750mAh Li-ion

KPN 500 Micro / Chicago 700E Series — 3.7V Li-ion Replacement Battery

This 3.7V 750mAh Li-ion battery fits the KPN 500 Micro, Chicago 700E, and Chicago 700E BT cordless DECT handsets. It slots into the handset battery compartment and restores talk and standby function when the original cell no longer holds a charge. Capacity is 750mAh (2.78Wh), matching the original cell specification.

• 500 Micro and Chicago 700E compatibility: These three handsets share the same 3.7V Li-ion cell format, physical footprint (50.20 × 37.50 × 7.65mm), and connector orientation. One battery fits all three without modification.
• Bench tested on actual hardware: We cycled this cell on the 500 Micro platform and confirmed the BMS accepted charge from the base station without error. Voltage held steady at 3.7V nominal across the discharge curve with no premature cutoff.
• First charge after install: Li-ion cells lose some charge during storage. Place the handset in the base immediately after fitting the new battery and leave it for a full charge cycle before using the handset — this brings the cell to rated capacity from its stored state.

Talk time shorter than the original battery after replacement

A fresh Li-ion cell shipped in storage mode often starts at 30–50% charge, so the first one or two cycles will feel short. The cell needs two to three full charge and use cycles before it reaches its rated 750mAh capacity. Do not judge talk time on the first charge. After three cycles, if talk time is still noticeably short, check the handset contacts and base cradle contacts for corrosion — a dirty contact raises internal resistance and limits charge transfer.

Base station shows no charge light or error after new battery is installed

If the base station does not show a charge indicator after you seat the handset, the cell voltage may have dropped below the base unit's acceptance threshold during storage. Remove the handset, wait ten seconds, and reseat it firmly — this resets the charge handshake. If the base still shows no activity, check that the handset is fully seated and the gold contacts on both handset and cradle are clean and making solid contact. A brief wipe with a dry cloth on both contact sets resolves most no-charge errors.