HB5F2H Huawei E5373 Replacement Battery 3.7V 1700mAh

Huawei E5373 / E5375 Series — 3.7V Li-ion Replacement Battery (HB5F2H)

This is a 3.7V, 1700mAh Li-ion replacement battery for the Huawei E5373, E5375, EC5377, E5330, and seven additional E-series mobile hotspot models. It slots into the same battery bay as the original HB5F2H and HB554666RAW units. The hotspot manages both the cellular modem and the Wi-Fi radio from this single cell.

• E5373 / E5375 / EC5377 / E5330 compatibility: These models share the same battery bay dimensions, connector pin-out, and BMS communication protocol. The hotspot firmware reads charge state directly from the battery over the data line — swap is straight-forward because the handshake is identical across the group.
• Bench tested on actual hardware: We ran this cell on the E5373 with four simultaneous connected clients and monitored BMS cutoff thresholds. The protection circuit held the low-voltage cutoff at the correct 3.0V floor and did not trigger a false over-current trip during the combined modem and Wi-Fi radio draw.
• Ventilation during extended sessions: Keep the hotspot on a hard, flat surface — not in a bag or pocket — during long sessions. When the connected device is far from the hotspot, the cellular radio runs at maximum transmit power, raising battery temperature and accelerating cell wear over time.

Why the E5373 drops all connected clients mid-session under load

The E5373 drives two separate radios simultaneously — the cellular modem and the 802.11 Wi-Fi module. At maximum client count, combined current draw spikes briefly above the single-radio idle draw. An aged or degraded cell cannot maintain voltage under that spike, and the BMS reads it as an under-voltage event, cutting output and dropping all clients. A fresh cell with the full 1700mAh capacity holds the voltage rail stable through those spikes. If drop-outs persist after fitting a new battery, check signal strength — weak cellular signal forces the modem to draw even more current to maintain the connection.

Hotspot shows a charge indicator but will not boot after sitting unused

After extended storage, a Li-ion cell can drop below the minimum boot voltage even if it was stored partially charged. The E5373 firmware requires enough voltage to initialise the modem before it will complete the boot sequence — a battery sitting at 2.8V or below will fail that check and the device will not turn on. Connect the hotspot to the charger and leave it for at least 30 minutes before attempting to power it on. If the LED indicator does not respond at all, the cell may need to recover from deep discharge — continue charging and try booting once the indicator changes state, typically when cell voltage reaches 3.4V.