Bizlander 2W30LED Solar Replacement Battery 3.7V 2600mAh

Bizlander 2W30LED — 3.7V Li-ion Replacement Battery (BT4SKUSL-30)

This 3.7V 2600mAh Li-ion cell replaces the factory battery in the Bizlander 2W30LED outdoor solar garden light. It fits the integrated battery bay directly, matching the original OEM part number BT4SKUSL-30. Swap it in when dim output or shortened night cycles signal the original cell has degraded past useful capacity.

• 2W30LED solar light fit: The 2W30LED uses a single 3.7V Li-ion cell sized at 68.70 × 18.60 × 18.60mm — this replacement matches that form factor, voltage rail, and BMS handshake so the charge controller reads the cell correctly from the first solar cycle.
• Bench tested on actual hardware: We cycled this cell through a full solar-input charge profile and confirmed the BMS accepts charge current at the panel's typical 100–300mA output range without triggering an over-current fault or false full-charge cutoff.
• Solar panel angle after installation: After fitting the new cell, orient the panel face perpendicular to direct sun — even a 30-degree tilt in late afternoon can drop panel output below the BMS minimum input threshold, leaving the battery only partially charged before dusk.

Why the 2W30LED dims or cuts off before dawn

The LED driver in the 2W30LED runs until cell voltage drops to the BMS low-cutoff point, typically around 2.8–3.0V for a 3.7V Li-ion cell. An aged cell reaches that threshold faster because internal resistance has risen, causing voltage to sag under the LED load even when nominal capacity looks adequate. A fresh 2600mAh cell at full charge holds a stable voltage curve long enough to cover a full night cycle in most climates. If the light still cuts early after replacement, the panel is not delivering enough current to fully charge the cell — check for shading or surface dirt on the panel face.

Replacement cell shows no charge after first full day of sun

A new Li-ion cell shipped at partial state of charge — typically 30–50% — to comply with transport safety rules. If the solar panel output is marginal (shaded location, overcast day, or poor angle), the BMS may not log any net charge gain above that storage level. Move the light to a position with unobstructed direct sun and give it a full clear day; panel output needs to reach at least the BMS minimum input threshold, around 4.2V open-circuit, to begin active charging. If sunlight access is limited, connect via USB if the unit supports it — USB input at 5V overrides the panel path and charges the cell to full in a single session.