Unisonic TP7087 Cordless Phone Compatible Battery 3.6V 170mAh

Unisonic TP7087 — 3.6V Ni-MH Replacement Battery

This is a 3.6V Ni-MH replacement battery rated at 170mAh (0.61Wh) for the Unisonic TP7087 cordless telephone handset. It fits directly into the handset battery compartment and restores cordless operation when the original cell no longer holds charge. Dimensions are 50.60 x 25.83 x 14.07mm.

• TP7087 handset compatibility: The TP7087 uses a compact 3-cell Ni-MH pack at 3.6V nominal. The base station's charging circuit expects that specific voltage window — swapping in a cell outside this range causes the base to flag a charge fault or refuse to charge entirely.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench. The cell voltage held within the expected Ni-MH window across the first five cycles, and the base station's charge indicator responded correctly throughout.
• First-charge protocol for Ni-MH cordless packs: After installing, seat the handset in the base and leave it for a full 16 hours before the first use. Ni-MH cells shipped in a partially discharged state need this slow initial charge to reach rated capacity — skipping it results in shortened talk time from day one.

Base station showing no charge light after battery swap

Ni-MH packs lose voltage during storage and can arrive below the threshold the base station needs to detect a valid battery. If the charge indicator stays dark after seating the handset, the pack voltage is too low for the base to start its charge cycle. Remove the handset, wait 10 seconds, and reseat it firmly — some bases require a clean contact before initiating charge. If that fails, check resting voltage at the battery terminals; a reading below 3.0V confirms the pack needs a slow external boost charge to get above the base's acceptance threshold.

Range drops noticeably after replacing the battery

Reduced range after a battery swap is almost always a voltage sag issue, not a pairing or antenna problem. Under RF transmit load, a Ni-MH pack that hasn't been properly conditioned will sag in voltage, causing the handset's transmit power to pull back. This typically resolves after three to five full charge and discharge cycles, which bring the cells to rated capacity. If range is still short after five cycles, check that the battery contacts in the handset are clean and making firm contact — oxidised pins add resistance and compound the sag.