NET10 Z289L Replacement Battery 3.7V 3000mAh Li-ion

NET10 Z289L / SRQ-Z289L — 3.7V Li-ion Replacement Battery

This is a 3.7V, 3000mAh Li-ion battery for the NET10 Z289L and SRQ-Z289L mobile hotspot. It fits directly into the hotspot's battery bay and restores power to the device's combined cellular modem and Wi-Fi radio system. Capacity figures are drawn from the product specification, not third-party claims.

• Z289L and SRQ-Z289L compatibility: Both the Z289L and SRQ-Z289L share the same battery bay dimensions and 3.7V power rail. The onboard BMS accepts the same charge profile across both variants, so one battery fits both units without modification.
• Bench tested on actual hardware: We ran this battery under sustained multi-device load — modem active, Wi-Fi broadcasting to several connected clients simultaneously. The BMS held the voltage rail steady and did not trip a low-voltage cutoff during the test cycle.
• Ventilation during extended hotspot sessions: When connected devices are far from the hotspot, the cellular radio runs at maximum output power to maintain signal. Place the Z289L on an open, hard surface during long sessions — blocking the rear vents traps heat directly against the battery cell.

Why the Z289L disconnects connected devices mid-session on a new battery

The Z289L runs two high-draw subsystems simultaneously — a cellular modem and a Wi-Fi radio. At maximum client connections, combined current draw can cause a brief voltage sag on the battery rail. If the sag crosses the BMS undervoltage threshold, even momentarily, the BMS cuts power to protect the cell. This appears to connected devices as a sudden hotspot dropout rather than a battery failure. Reducing active client connections or moving the hotspot closer to the cellular tower lowers radio output power and reduces the sag.

Z289L won't power on after sitting unused for several weeks

Li-ion cells self-discharge at roughly 1–2% per week during storage. If the Z289L sat long enough, the battery may have dropped below the minimum boot voltage — typically around 3.0V for this cell class. The device will appear completely dead and will not respond to the power button. Connect it to the original charger and leave it on charge uninterrupted for at least 30–60 minutes before attempting to power on; the charger's preconditioning circuit needs time to bring the cell back above the 3.0V boot threshold.