Bluetti B300S Extra Battery – 3,072Wh LiFePO4 Expansion for AC300S/AC500

Bluetti B300S Extra Battery – 3,072Wh LiFePO4 Expansion Module for AC300S/AC500

The Bluetti B300S is Bluetti’s highest-capacity single battery module — adding 3,072Wh of LiFePO4 energy storage per unit to the AC300S or AC500 inverter systems. Connect up to six B300S modules for a total system capacity of 18,432Wh, creating one of the most powerful residential battery backup systems commercially available.

About This Item

• 3,072Wh Per Module: Each B300S adds 3,072Wh of LiFePO4 capacity — enough to run a refrigerator for 30+ hours, power an average home for 12+ hours, or maintain essential circuits through multi-day outages.
• Compatible with AC300S and AC500: Designed specifically for Bluetti’s professional-grade AC300S and AC500 inverter units via a simple cable connection requiring no technical expertise.
• Scale to 18,432Wh: Connect up to 6 B300S units to the AC500 for a staggering 18,432Wh total system capacity — enough to power a large home through several days without solar.
• 3,500-Cycle LiFePO4 Chemistry: LiFePO4 provides 3,500+ charge cycles with minimal degradation — approximately 9.6 years of daily charging — and inherent thermal stability preventing thermal runaway risks.
• 200A Integrated BMS: The built-in 200-amp Battery Management System provides real-time cell monitoring, balancing, and protection against all common battery failure modes for maximum safety and longevity.
• Silent Operation: Passive thermal management requires no cooling fans, resulting in completely silent operation 24/7 — ideal for bedroom backup and home office locations.
• Bluetti App Monitoring: Monitor individual module state, cell voltage, temperature, and total system energy via the Bluetti app for proactive maintenance and optimization.

Product Information

Customer Reviews Highlights

★★★★½ 4.5/5 from 890+ verified buyers — Professional off-grid system builders consistently describe the B300S as the best value per kWh in the large-format battery module category. The 18,432Wh maximum system capacity is described as genuinely sufficient for multi-day whole-home backup in most US climates. Silent passive cooling gets consistent praise from customers who locate the batteries near sleeping areas.