20V 4Ah Lithium-ion Battery
B40X2
(5.0)Charger | Battery(Ah) | ||||||
B20X2 | B25X2 | B40X2 | B50X2 | B60X2 | B80X2 | ||
（18650） | （18650） | （18650） | （18650） | （21700） | （21700） | ||
CHX2-L1-EU | 80min | 95min | 160min | 190min | 250min | 330min | |
CHX2 | 65min | 85min | 135min | 160min | 195min | 260min | |
CHQX2 | 35min | 45min | 65min | 85min | 105min | 140min | |
CHQX2-M-EU | 35min | 45min | 50min | 60min | 75min | 100min | |
Charging two batteries at the same time | CHDX2-M-EU | 80min | 95min | 100min | 140min | 155min | 195min |
6.0A Dual-port charger-- Charging only one battery | 40min | 50min | 55min | 70min | 85min | 110min | |
Note: The battery pack charging time error is ±5min | |||||||
KEY FEATURES
Compact & Lightweight Design – The battery is easy to handle, store, and swap, reducing fatigue during long tasks.
Advanced Safety BMS – Built-in Battery Management System ensures protection against overcharging, overheating, and short circuits for long-lasting performance.
TECHNICAL PARAMETERS
Model | B40X2 |
Voltage | 20V Max |
Battery Type | Lithium-ion |
Rated Capacity | 4Ah / 72Wh |
Machine Weight | 0.63kg |
Series-parallel system | 5S2P |
Cell Type | 18650 |
Recommended Ambient Temperature for Charging | 41°F~104°F(5°C~40°C) |
Optimum Storage Temperature in use | 50°F~80°F(10°C~26°C) |
Certification | UN38.3, UL 2595 |
Machine Size | 119.9*76.5*68.7mm |
SUPPORT
Product Overview
The SENIX X2 20V Max 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 20V Max and 2X2 40V Max 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.
Warranty Information
We offer a comprehensive warranty policy tailored to the specific requirements of different countries and regions. Our warranty coverage is designed to ensure customer satisfaction and product reliability across all markets. For detailed information regarding the terms, duration, and service procedures applicable in your location, please get in touch with us directly. Our team will provide you with a complete warranty illustration and support as needed.
FREQUENTLY ASKED QUESTIONS
- Q1: Can I use the 4.0Ah battery with all SENIX 20V tools?
Yes, the B40X2 is fully compatible with all SENIX X2 20V platform tools.
Q2: How does it compare to the 2.0Ah and 2.5Ah batteries?
The 4.0Ah offers significantly longer runtime, though it’s heavier (0.63 kg vs. 0.37–0.39 kg).
Q3: How long does it take to charge?
With a standard SENIX charger, expect 50-135 minutes depending on charger output.
Q4: Does the LED indicator show charging progress?
No, it shows remaining battery life when in use, not charging status.
Q5: Is the battery safe for professional daily use?
Yes, with its advanced BMS and certifications, it’s designed for both DIY and professional reliability.
