Retevis RT1 7.4V 1800mAh Replacement Battery Li-ion

Retevis RT1 — 7.4V Li-ion Replacement Battery (RT1)

This 7.4V, 1800mAh lithium-ion pack is a direct replacement for the Retevis RT1 handheld two-way radio. It fits the RT1 transceiver and restores full transmit power after the original cell degrades. Capacity is sourced from the product specification — 13.32Wh total energy at nominal voltage.

• RT1 platform fit: The RT1 battery bay uses a fixed contact layout and a specific connector pitch. This pack matches that layout, so the contacts seat flush and the BMS handshake with the charger dock completes without adapter hardware.
• Bench tested on actual hardware: We cycled this pack through transmit-load draws at the RT1's rated output. The BMS held the discharge curve steady and tripped at the correct low-voltage cutoff without nuisance shutdowns during the RF output phase.
• First insertion into the RT1 charger dock: If the dock LED shows fault on first seating, remove the pack and wipe the gold contact strip with a dry cloth before reseating. The RT1 dock requires a clean contact cycle to accept the new BMS handshake and begin the charge sequence.

Why the RT1 cuts out mid-transmission on a new battery at storage voltage

Cells ship at roughly 3.7V per cell — around 7.4V total — to meet transport regulations. That is at the low end of the RT1's usable voltage window. When PTT is pressed, transmit current spikes sharply, and the BMS sees a momentary voltage drop that can cross the cutoff threshold before the cell has been conditioned. Running one full charge cycle before field use brings each cell up to 4.1–4.2V and gives the BMS the headroom it needs to handle transmit surges cleanly.

RT1 bar indicator stuck on two bars after a full charge

The RT1 uses a voltage-threshold bar display — it reads the pack's resting voltage and maps it to bars. A new cell fresh off storage voltage will show fewer bars than expected even after the charger LED goes green, because the cell needs a full discharge-recharge cycle to reach its rated resting voltage. This is not a fault in the pack or the indicator circuit. Run the radio until the low-battery warning shows, then charge to completion — the resting voltage after that cycle should read above 8.2V and the indicator will show full bars.