Solar Battery Comparison Guide (2026) | PES Supply
Solar Battery Comparison Guide (2026)
Compare battery types, sizes, and brands for solar energy storage
Top Solar Batteries Compared
| Battery | Capacity | Chemistry | Cycles | Price Range |
|---|---|---|---|---|
| Tesla Powerwall 2 | 13.5 kWh | NMC Li-ion | 5,000+ | $8,500-$11,000 |
| EG4 LifePower4 | 5.12 kWh (modular) | LiFePO4 | 7,000+ | $1,500-$2,000/5kWh |
| Enphase IQ Battery 10C | 10.08 kWh | LFP | 6,000+ | $8,000-$10,000 |
| MidNite Solar PowerFlo16 | 16 kWh | LiFePO4 | 6,000+ | $5,500-$7,000 |
| Fortress Power eVault Max | 18.5 kWh | LiFePO4 | 6,000+ | $8,000-$11,000 |
How to Size Your Solar Battery
To determine the right battery size, calculate your critical loads (essential devices you want to power during an outage):
Battery Size = Total Load (W) × Runtime (hours) / (Voltage × DoD × Efficiency)
Example: 2,000W × 8 hours / (48V × 0.95 × 0.9) = 39 Ah @ 48V = ~1.9 kWh
Battery Chemistry Comparison
| Chemistry | Cycle Life | Depth of Discharge | Safety | Cost/kWh |
|---|---|---|---|---|
| LiFePO4 (LFP) | 6,000-8,000 | 100% | Excellent | $300-$500 |
| NMC Li-ion | 3,000-5,000 | 80-90% | Good | $400-$600 |
| AGM Lead-Acid | 500-1,200 | 50% | Good | $200-$300 |
| Saltwater | 5,000+ | 100% | Excellent | $400-$600 |
How Many Batteries Do I Need?
| Backup Goal | Required Energy | Battery Recommendation |
|---|---|---|
| Essentials only (8 hrs) | 5-8 kWh | 1× Tesla Powerwall 2 or 2× EG4 5kWh |
| Most of home (12 hrs) | 10-15 kWh | 1× Enphase IQ 10C or 3× EG4 5kWh |
| Whole home (24 hrs) | 20-30 kWh | 1× Fortress eVault + EG4, or 5× EG4 |
| Off-grid (2 days) | 30-50 kWh | MidNite PowerFlo16 + EG4 stack |