About this replacement
D-Link DWR-730 / DWR-720 B1 — 3.7V Li-ion Replacement Battery (DWRr300a)
This 3.7V 2350mAh Li-ion battery replaces the original cell in the D-Link DWR-730, DWR-730 B1, DWR-730 B2, and DWR-720 B1 portable mobile hotspots. These devices share a common battery footprint and BMS handshake across the range, so one cell covers the full group. Capacity is 2350mAh (8.7Wh), matching OEM specification.
- DWR-730 and DWR-720 B1 platform: Both lines run the same 3.7V single-cell architecture with an identical connector and BMS communication protocol. The hotspot firmware reads battery state directly from the BMS, so a correctly matched replacement reports charge level accurately to the device — no calibration gap at first boot.
- Bench tested on actual hardware: We cycled this cell under combined cellular modem and WiFi radio load — the conditions the BMS sees at maximum client connections. Charge cutoff triggered correctly at 4.2V and low-voltage protection engaged at the expected floor, with no false shutdowns mid-cycle.
- Ventilation during extended sessions: Keep the DWR-730 on a hard, open surface when running for long periods. The cellular radio pushes full transmit power when connected clients are at range limits, which raises internal temperature. Heat is the primary stressor on a Li-ion cell in this form factor — a blocked vent slot accelerates capacity loss faster than charge cycles alone.
Voltage sag when the DWR-730 hits maximum client connections
The DWR-730 runs two power-hungry subsystems simultaneously — the cellular modem and the WiFi radio. When client count peaks and signal conditions are poor, combined draw spikes sharply. A degraded original cell cannot hold voltage under that spike, which triggers the BMS undervoltage cutoff and drops the hotspot. This replacement cell maintains a stable voltage rail under the same combined load, keeping the BMS above the cutoff threshold during peak-draw moments.
DWR-730 not powering on after sitting unused
Li-ion cells self-discharge during storage, and the DWR-730 draws a small standby current even when switched off. After several weeks unused, the cell can drop below the minimum boot voltage the firmware requires — typically around 3.0V — and the device will show no response at the power button. Connect the hotspot to a charger for at least 15–20 minutes before attempting to power on. If the charge indicator does not respond within that window, the cell has likely dropped below the BMS recovery threshold and needs replacement.