EcoFlow DELTA 2 vs HomeGrid Stack'd Series 28.8kWh
The HomeGrid Stack'd Series 28.8kWh wins this battery comparison by a decisive margin. It delivers 28.8 kWh of usable storage with 25.8 kW continuous output and a 6,000-cycle rating, backed by a longer 10-year warranty. The 28.0 kWh capacity advantage provides 37 additional hours of essential-load backup.
Key Differences
- • HomeGrid Stack'd Series 28.8kWh provides 28.8 kWh vs 0.819 kWh usable capacity.
- • HomeGrid Stack'd Series 28.8kWh achieves 96% round-trip efficiency vs 90%.
- • HomeGrid Stack'd Series 28.8kWh offers a longer 10-year warranty vs 5 years.
- • HomeGrid Stack'd Series 28.8kWh is rated for 6,000 cycles vs 3,000.
Specifications Breakdown
Usable Storage Capacity
The EcoFlow DELTA 2 provides 0.819 kWh of usable capacity (1.024 kWh total, 80% DoD), while the HomeGrid Stack'd Series 28.8kWh offers 28.8 kWh usable (28.8 kWh total, 100% DoD). At an average essential-load consumption rate of 750 watts, the EcoFlow DELTA 2 provides approximately 1.1 hours of backup versus 38.4 hours for the HomeGrid Stack'd Series 28.8kWh. The HomeGrid Stack'd Series 28.8kWh's 28.0 kWh capacity advantage translates to roughly 37 additional hours of essential-load backup during a grid outage. The EcoFlow DELTA 2 is scalable up to 2 units (2 kWh total), while the HomeGrid Stack'd Series 28.8kWh scales up to 15 units (432 kWh total).
Power Output
The EcoFlow DELTA 2 delivers 1.8 kW continuous and 2.7 kW peak power, while the HomeGrid Stack'd Series 28.8kWh provides 25.8 kW continuous and 40 kW peak. The HomeGrid Stack'd Series 28.8kWh'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 HomeGrid Stack'd Series 28.8kWh's 40 kW peak is capable of starting most residential HVAC systems.
Battery Chemistry & Cycle Life
The EcoFlow DELTA 2 uses LFP chemistry with a rated cycle life of 3,000 cycles (approximately 8.2 years of daily cycling), while the HomeGrid Stack'd Series 28.8kWh uses LFP with 6,000 cycles (approximately 16.4 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 HomeGrid Stack'd Series 28.8kWh'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 EcoFlow DELTA 2 achieves 90% round-trip efficiency versus 96% for the HomeGrid Stack'd Series 28.8kWh. This means for every 10 kWh of solar energy stored in the HomeGrid Stack'd Series 28.8kWh, 9.6 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 $493 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 EcoFlow DELTA 2 carries a 5-year warranty, while the HomeGrid Stack'd Series 28.8kWh offers 10 years. The HomeGrid Stack'd Series 28.8kWh provides 5 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 | EcoFlow DELTA 2 | HomeGrid Stack'd Series 28.8kWh |
|---|---|---|
| Capacity | 1.024 kWh | 28.8 kWh |
| Usable Capacity | 0.819 kWh | 28.8 kWh |
| Power Output | 1.8 kW | 25.8 kW |
| Chemistry | LFP (Lithium Iron Phosphate) | LFP (Lithium Iron Phosphate) |
| Efficiency | 90% | 96% |
| Cycle Life | 3,000 | 6,000 |
| Weight | 12 kg | 206 kg |
| Warranty | 5 years | 10 years |
| Scalable | Yes | Yes |
5-Dimension Head-to-Head Analysis
1. Storage Capacity
Winner: HomeGrid Stack'd Series 28.8kWhThe HomeGrid Stack'd Series 28.8kWh provides 28.8 kWh versus 0.819 kWh — 28.0 kWh more usable storage. At typical essential-load consumption of 0.75 kW, this equals approximately 37 additional hours of backup power. This is a substantial capacity gap.
2. Power Output
Winner: HomeGrid Stack'd Series 28.8kWhThe HomeGrid Stack'd Series 28.8kWh delivers 25.8 kW continuous versus 1.8 kW. This is enough to run a central AC unit, refrigerator, and general household loads simultaneously. The 24.0 kW power gap significantly impacts what appliances you can run during outages.
3. Chemistry & Longevity
Winner: HomeGrid Stack'd Series 28.8kWhBoth use LFP chemistry with EcoFlow DELTA 2 at 3,000 cycles vs HomeGrid Stack'd Series 28.8kWh at 6,000 cycles. LFP chemistry provides excellent thermal stability, long cycle life, and no cobalt dependency.
4. Round-Trip Efficiency
Winner: HomeGrid Stack'd Series 28.8kWhThe HomeGrid Stack'd Series 28.8kWh achieves 96% round-trip efficiency versus 90%. Over 10 years of daily cycling with 15 kWh throughput per day, the more efficient battery saves approximately 493 dollars in energy that would otherwise be lost as heat (at $0.15/kWh). This efficiency gap is significant and meaningfully impacts lifetime economics.
5. Warranty Coverage
Winner: HomeGrid Stack'd Series 28.8kWhThe HomeGrid Stack'd Series 28.8kWh offers a 10-year warranty versus 5 years. Consider the remaining warranty period when evaluating total cost of ownership.
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
HomeGrid Stack'd Series 28.8kWh
The HomeGrid Stack'd Series 28.8kWh uses 6 modules for a full day of storage for average US households. With 25.8 kW continuous power output, it handles whole-home backup including HVAC, EV charging, and high-draw appliances simultaneously.
Pros
- + 28.8 kWh covers a full day of average US household consumption
- + 25.8 kW continuous output handles any residential load scenario
- + Tool-free modular design — no inter-module wiring needed
- + UL 9540 and UL 9540A fire safety certified
Cons
- - 206kg requires dedicated floor space and structural support
- - High upfront cost for full 6-module configuration
- - 48V architecture means very high current at full power output
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.
Choose HomeGrid Stack'd Series 28.8kWh 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 10-year warranty gives you the confidence you need
Our Recommendation
The HomeGrid Stack'd Series 28.8kWh 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 HomeGrid Stack'd Series 28.8kWh is the stronger choice for virtually every installation scenario.
Frequently Asked Questions
Which is better, EcoFlow DELTA 2 or HomeGrid Stack'd Series 28.8kWh?
The HomeGrid Stack'd Series 28.8kWh wins this battery comparison by a decisive margin. It delivers 28.8 kWh of usable storage with 25.8 kW continuous output and a 6,000-cycle rating, backed by a longer 10-year warranty. The 28.0 kWh capacity advantage provides 37 additional hours of essential-load backup.
Which battery lasts longer?
The EcoFlow DELTA 2 is rated for 3,000 cycles versus 6,000 for the HomeGrid Stack'd Series 28.8kWh. HomeGrid Stack'd Series 28.8kWh lasts approximately 8 more years of daily cycling. LFP chemistry generally outlasts NMC in cycle life testing.
Which battery provides more backup power?
The EcoFlow DELTA 2 provides 1.8 kW continuous (2.7 kW peak) versus 25.8 kW continuous (40 kW peak) for the HomeGrid Stack'd Series 28.8kWh. HomeGrid Stack'd Series 28.8kWh 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 EcoFlow DELTA 2 or HomeGrid Stack'd Series 28.8kWh storage later?
EcoFlow DELTA 2: Yes, up to 2 units for 2 kWh total. HomeGrid Stack'd Series 28.8kWh: Yes, up to 15 units for 432 kWh total. HomeGrid Stack'd Series 28.8kWh 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