Panasonic EverVolt AC Series EVAC-105 vs EcoFlow DELTA 2
The Panasonic EverVolt AC Series EVAC-105 wins this battery comparison by a decisive margin. It delivers 17.1 kWh of usable storage with 9 kW continuous output and a 6,000-cycle rating, backed by a longer 15-year warranty. The 16.3 kWh capacity advantage provides 22 additional hours of essential-load backup.
Key Differences
- • Panasonic EverVolt AC Series EVAC-105 provides 17.1 kWh vs 0.819 kWh usable capacity.
- • Panasonic EverVolt AC Series EVAC-105 achieves 92% round-trip efficiency vs 90%.
- • Panasonic EverVolt AC Series EVAC-105 offers a longer 15-year warranty vs 5 years.
- • Panasonic EverVolt AC Series EVAC-105 is rated for 6,000 cycles vs 3,000.
Specifications Breakdown
Usable Storage Capacity
The Panasonic EverVolt AC Series EVAC-105 provides 17.1 kWh of usable capacity (17.1 kWh total, 100% DoD), while the EcoFlow DELTA 2 offers 0.819 kWh usable (1.024 kWh total, 80% DoD). At an average essential-load consumption rate of 750 watts, the Panasonic EverVolt AC Series EVAC-105 provides approximately 22.8 hours of backup versus 1.1 hours for the EcoFlow DELTA 2. The Panasonic EverVolt AC Series EVAC-105's 16.3 kWh capacity advantage translates to roughly 22 additional hours of essential-load backup during a grid outage. The Panasonic EverVolt AC Series EVAC-105 is scalable up to 4 units (68 kWh total), while the EcoFlow DELTA 2 scales up to 2 units (2 kWh total).
Power Output
The Panasonic EverVolt AC Series EVAC-105 delivers 9 kW continuous and 11 kW peak power, while the EcoFlow DELTA 2 provides 1.8 kW continuous and 2.7 kW peak. The Panasonic EverVolt AC Series EVAC-105's higher continuous output means it can simultaneously power more demanding appliances during an outage. A central air conditioner typically draws 3-5 kW, a refrigerator 0.1-0.2 kW, and an EV Level 2 charger 7-11 kW. Peak power rating matters for motor-driven loads with high startup current, such as air conditioners, well pumps, and sump pumps. The Panasonic EverVolt AC Series EVAC-105's 11 kW peak is capable of starting most residential HVAC systems.
Battery Chemistry & Cycle Life
The Panasonic EverVolt AC Series EVAC-105 uses LFP chemistry with a rated cycle life of 6,000 cycles (approximately 16.4 years of daily cycling), while the EcoFlow DELTA 2 uses LFP with 3,000 cycles (approximately 8.2 years). Both use LFP chemistry, which is considered the gold standard for residential energy storage due to its inherent safety, long cycle life, and environmental friendliness. The Panasonic EverVolt AC Series EVAC-105's additional 3,000 cycles translates to approximately 8.2 more years of daily use before reaching the rated end of life.
Round-Trip Efficiency
The Panasonic EverVolt AC Series EVAC-105 achieves 92% round-trip efficiency versus 90% for the EcoFlow DELTA 2. This means for every 10 kWh of solar energy stored in the Panasonic EverVolt AC Series EVAC-105, 9.2 kWh is recoverable, compared to 9.0 kWh for the other. Over 10 years of daily cycling with 15 kWh average daily throughput, the more efficient battery saves approximately $164 in energy that would otherwise be lost as heat (at $0.15/kWh average retail rate). Higher round-trip efficiency is especially valuable in time-of-use rate environments where you are storing cheap off-peak energy for expensive peak-hour consumption.
Warranty & Long-Term Protection
The Panasonic EverVolt AC Series EVAC-105 carries a 15-year warranty, while the EcoFlow DELTA 2 offers 5 years. The Panasonic EverVolt AC Series EVAC-105 provides 10 additional years of manufacturer protection against capacity degradation and defects. Battery warranties typically guarantee the unit will retain 60-70% of original capacity by end of warranty, so the length of coverage directly impacts your financial risk over the system's lifetime.
Specification Comparison
| Specification | Panasonic EverVolt AC Series EVAC-105 | EcoFlow DELTA 2 |
|---|---|---|
| Capacity | 17.1 kWh | 1.024 kWh |
| Usable Capacity | 17.1 kWh | 0.819 kWh |
| Power Output | 9 kW | 1.8 kW |
| Chemistry | LFP (Lithium Iron Phosphate) | LFP (Lithium Iron Phosphate) |
| Efficiency | 92% | 90% |
| Cycle Life | 6,000 | 3,000 |
| Weight | 150 kg | 12 kg |
| Warranty | 15 years | 5 years |
| Scalable | Yes | Yes |
5-Dimension Head-to-Head Analysis
1. Storage Capacity
Winner: Panasonic EverVolt AC Series EVAC-105The Panasonic EverVolt AC Series EVAC-105 provides 17.1 kWh versus 0.819 kWh — 16.3 kWh more usable storage. At typical essential-load consumption of 0.75 kW, this equals approximately 22 additional hours of backup power. This is a substantial capacity gap.
2. Power Output
Winner: Panasonic EverVolt AC Series EVAC-105The Panasonic EverVolt AC Series EVAC-105 delivers 9 kW continuous versus 1.8 kW. This is enough to run a central AC unit, refrigerator, and general household loads simultaneously. The 7.2 kW power gap significantly impacts what appliances you can run during outages.
3. Chemistry & Longevity
Winner: Panasonic EverVolt AC Series EVAC-105Both use LFP chemistry with Panasonic EverVolt AC Series EVAC-105 at 6,000 cycles vs EcoFlow DELTA 2 at 3,000 cycles. LFP chemistry provides excellent thermal stability, long cycle life, and no cobalt dependency.
4. Round-Trip Efficiency
Winner: Panasonic EverVolt AC Series EVAC-105The Panasonic EverVolt AC Series EVAC-105 achieves 92% round-trip efficiency versus 90%. Over 10 years of daily cycling with 15 kWh throughput per day, the more efficient battery saves approximately 164 dollars in energy that would otherwise be lost as heat (at $0.15/kWh). The difference is moderate but compounds over the battery's lifespan.
5. Warranty Coverage
Winner: Panasonic EverVolt AC Series EVAC-105The Panasonic EverVolt AC Series EVAC-105 offers a 15-year warranty versus 5 years. This is among the longest battery warranties in the residential market.
Panasonic EverVolt AC Series EVAC-105
The Panasonic EverVolt AC Series EVAC-105 is the AC-coupled variant of the EverVolt 2.0 platform, delivering 17.1 kWh of LFP storage with 9 kW of continuous backup power. As an AC-coupled system, it retrofits seamlessly with any existing solar installation regardless of inverter brand. The 15-year warranty reflects Panasonic's confidence in the LFP cell chemistry and advanced thermal management system. Four units can be combined for 68.4 kWh of total storage, making it one of the highest-capacity residential AC-coupled configurations available on the market.
Pros
- + 17.1 kWh is among the largest single-unit residential battery capacities
- + 9 kW continuous output supports heavy loads during backup
- + 15-year warranty with LFP chemistry for exceptional longevity
- + AC-coupled design retrofits with any existing solar inverter
Cons
- - Heavy at 150 kg, requiring robust mounting or floor placement
- - AC-coupled conversion adds slight efficiency loss compared to DC-coupled
- - Premium pricing reflects Panasonic brand and larger capacity
EcoFlow DELTA 2
The EcoFlow DELTA 2 is a 1 kWh LiFePO4 portable power station with 1,800W output (2,700W X-Boost), 500W solar input, 80-minute AC fast charge, and expandable capacity to 3 kWh with an extra battery. It supports EcoFlow's smart home panel integration for basic home backup.
Pros
- + 1,800W output handles most household appliances
- + LFP chemistry with 3,000 cycles to 80%
- + Fast 80-minute AC charging
- + Expandable to 3 kWh with DELTA 2 Extra Battery
- + Smart home panel integration for circuit-level home backup
- + EcoFlow app with comprehensive monitoring
Cons
- - 1 kWh base capacity is modest for home backup
- - 3,000 cycles lower than competitors' 3,500-4,000
- - Expansion battery adds $600-$900 to system cost
- - X-Boost mode reduces output waveform purity
Choose Panasonic EverVolt AC Series EVAC-105 If...
- ✓ You need more backup storage to cover overnight consumption or extended outages
- ✓ You need to power demanding appliances (AC, EV charger) simultaneously during outages
- ✓ Maximum battery longevity (6,000 cycles) is your top priority
- ✓ You want to minimize energy losses during daily charge/discharge cycling
- ✓ A 15-year warranty gives you the confidence you need
Choose EcoFlow DELTA 2 If...
- ✓ Versatile home and outdoor users wanting a mid-size LFP power station that doubles as basic home backup with smart panel integration.
Our Recommendation
The Panasonic EverVolt AC Series EVAC-105 is the decisive winner in this battery comparison, outperforming the EcoFlow DELTA 2 in 5 of 5 dimensions. Unless you have a specific requirement that the EcoFlow DELTA 2 uniquely addresses, the Panasonic EverVolt AC Series EVAC-105 is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, Panasonic EverVolt AC Series EVAC-105 or EcoFlow DELTA 2?
The Panasonic EverVolt AC Series EVAC-105 wins this battery comparison by a decisive margin. It delivers 17.1 kWh of usable storage with 9 kW continuous output and a 6,000-cycle rating, backed by a longer 15-year warranty. The 16.3 kWh capacity advantage provides 22 additional hours of essential-load backup.
Which battery lasts longer?
The Panasonic EverVolt AC Series EVAC-105 is rated for 6,000 cycles versus 3,000 for the EcoFlow DELTA 2. Panasonic EverVolt AC Series EVAC-105 lasts approximately 8 more years of daily cycling. LFP chemistry generally outlasts NMC in cycle life testing.
Which battery provides more backup power?
The Panasonic EverVolt AC Series EVAC-105 provides 9 kW continuous (11 kW peak) versus 1.8 kW continuous (2.7 kW peak) for the EcoFlow DELTA 2. Panasonic EverVolt AC Series EVAC-105 can run more appliances simultaneously during an outage. A central AC typically needs 3-5 kW, a refrigerator 0.2 kW, and an EV charger 7-11 kW.
Can I expand Panasonic EverVolt AC Series EVAC-105 or EcoFlow DELTA 2 storage later?
Panasonic EverVolt AC Series EVAC-105: Yes, up to 4 units for 68 kWh total. EcoFlow DELTA 2: Yes, up to 2 units for 2 kWh total. Panasonic EverVolt AC Series EVAC-105 offers more expansion potential.
Which battery chemistry is safer?
Both use LFP (Lithium Iron Phosphate) chemistry, which is the safest lithium battery chemistry for residential use. LFP does not undergo thermal runaway, uses no cobalt, and is inherently stable.
Related Resources
Last updated: February 2026