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Lithium Battery Storage · 48V · 5.4kWh
Built with a goal of engineering the world's most robust lithium battery for every application scenario and the harshest weather conditions — the eFlex MAX 5.4 pairs a Tier 1 automotive-grade prismatic LiFePO4 cell with a patented enclosure design rated for 4x better thermal performance than competing batteries.
The eFlex MAX 5.4 is built around a Tier 1 automotive prismatic lithium iron phosphate cell — the same class of cell used in electric vehicles — chosen specifically for its high cycle life. A patented enclosure design delivers 4 times better thermal performance than competing batteries, backed by an IP65 dust- and water-proof rating that makes it suitable for outdoor installation. Mounting is flexible: wall mount, floor-stand, or 19" industrial server rack, so it fits into residential, commercial, or telecom-grade installations alike.
Electrical
| Nominal voltage | 51.2 V |
| Nominal capacity | 105 Ah |
| Rated capacity @ 0.5C (50A) | 5.374 kWh |
| Resistance | < 10 mΩ |
| Efficiency (at 0.5C) | > 98% |
| Self-discharge | < 1% / month |
| Maximum modules in parallel | 16 (86.4 kWh) |
| Depth of discharge | Up to 100% |
| Warranty | 10 years |
| Cycle life | 8,000 @ 80% DoD |
Charge
| Recommended charge current | < 55A |
| Maximum charge current | 100A |
| Recommended charge voltage | 54.4V |
| BMS charge voltage disconnect | > 56V |
Discharge
| Recommended continuous discharge | 60A (3kW DC) |
| Peak continuous discharge (60 min) | 100A (5kW) |
| Maximum surge power (5s) | 125A (6.6kW) |
| Recommended low-voltage disconnect | 48V |
| Battery low-voltage protection | < 45V |
| Battery recovery voltage | 45V |
| Fault current | 3,000A, 5ms |
Temperature
| Discharge temperature | -4°F to 131°F (-20°C to 55°C) |
| Charge temperature | 32°F to 114°F (0°C to 45°C) |
| Storage temperature | 20°F to 95°F (-6°C to 35°C) |
Mechanical
| Dimensions (L×W×H) | 17.5 × 7.2 × 24.2 in |
| Weight | 108 lbs (49 kg) |
| Terminal type | M8 |
| Ring terminal size | 3/8" or larger |
| Terminal torque | 7.0–7.7 Nm (5.1–5.7 ft-lb) |
| Terminal cover | 1 set, waterproof |
| Case material | Anodized aluminum |
| Enclosure protection | IP65 |
| Cell type / chemistry | Tier 1 automotive prismatic LiFePO4 |
Compliance & Charging Profile
| Certification | UL1973 |
| Shipping classification | UN38.3, Class 9 (lithium ion) |
| Bulk + absorb charge | 54.4V |
| Absorb time | 60 minutes |
| Float charge | 54V |
| Inverter charging | 2 stage / no float |
| Equalization | None typical (54.6V for 10s, rare) |
| Temperature compensation | None |
Free shipping on all orders within the mainland US (Hawaii, Alaska and overseas territories excluded - a freight forwarder is required). Orders ship directly from our brand partners' warehouses across the U.S. Order confirmation is emailed immediately; if an item is unexpectedly backordered we notify you before your card is charged. In-stock items are processed within 1-4 business days (cut-off 4:00 PM EST), transit is 3-6 business days, and tracking is emailed within 24 hours of shipment. Typical delivery is 4-10 business days from purchase. Minimum order value is $69.
You have 30 days from the delivery date to initiate a return (35 days for orders placed Nov 25-30 and Dec 25-31). Items must be unused, in original packaging with tags attached, and returns require prior authorization from our team.
To start a return: +1 (307) 317-7213, hello@ecosolarkits.com, or live chat. Read the full return and refund policy
