Product Overview

The SENIX X2 18V 4.0Ah Battery (Model B40X2) is designed for users who need longer runtime without sacrificing portability. At 0.63 kg, it’s slightly heavier than the 2.0Ah and 2.5Ah models, but it doubles capacity for extended work sessions.

Its LED power level display allows instant charge checks, while the advanced Battery Management System (BMS) ensures safety by protecting against overcharging, overheating, and short circuits. With a 5S2P 18650 lithium-ion cell system, the B40X2 provides 72Wh of energy—making it the go-to choice for heavy-duty applications.

Certified under UN38.3 and UL 2595, this battery meets strict safety and performance standards. Measuring 119.9 × 76.5 × 68.7 mm, it remains compact enough for easy swapping, charging, and storage. Designed for 41°F–104°F charging and best stored between 50°F–80°F, the B40X2 is a rugged, reliable companion for both DIY enthusiasts and professionals.

Usage Scenarios

Compatible with all SENIX X2 18V and 2X2 36V Cordless tools. 

Unrecommended Conditions

Do not expose the battery to water, heavy rain, or extremely humid environments.

Avoid charging or using the battery outside the recommended range (41°F–104°F / 5°C–40°C).

Do not store in temperatures above 80°F (26°C) or below freezing for long periods.

Not suitable for heavy-duty equipment requiring higher-capacity batteries.

SENIX Warranty at a Glance

Lithium Power Tools: 5 YEARS

Lithium Batteries & Chargers: 3 YEARS

Petrol Products: 2 YEARS (home) / 6 MONTHS (commercial)

Power Stations: 2 YEARS

Covers defects in materials and workmanship under normal use. Full terms available in the SENIX warranty policy.