3 × SigenStor BAT 8.0 (total system: 24.18 kWh capacity, 23.4 kWh usable)
| Parameter | Value |
|---|---|
| Battery chemistry | LiFePO4 (LFP) |
| Total energy capacity | 8.06 kWh |
| Usable energy capacity | 7.8 kWh |
| Max charge / discharge power | 4,000 W |
| Peak charge / discharge power (10 s) | 6,000 W |
| Operating temperature range | −20 °C to 55 °C |
| Recommended operating temperature | 15 °C to 30 °C |
| Ingress protection | IP66 |
| Cooling | Natural convection |
| Weight | 70 kg per unit |
| Dimensions (W/H/D) | 767 / 270 / 260 mm |
Test conditions (for rated figures): 100% depth of discharge, 0.2C rate charge/discharge, 25 °C.
| Units | Usable capacity | Max charge/discharge |
|---|---|---|
| 3 × BAT 8.0 | 23.4 kWh | 12 kW |
Source: Sigenergy Technology Co., Ltd. — Factory Limited Warranty for SigenStor (Europe), dated 14 May 2024.
| Product | Warranty period |
|---|---|
| Sigen Battery | 10 years |
| Sigen Energy Controller | 10 years |
| Sigen EV DC Charging Module | 3 years |
Warranty commences on the earlier of: (i) installation/activation/registration date, or (ii) date of retailer's invoice or delivery note. If neither is determinable, 6 months after manufacture date.
Sigenergy warrants the battery retains 70% of usable energy for 10 years OR until the Minimum Through Output Energy is reached — whichever comes first.
| Product | Usable energy | Minimum Through Output Energy (warranty cap) |
|---|---|---|
| Sigen Battery 5 kWh | 5.2 kWh | 15.85 MWh per unit |
| Sigen Battery 8 kWh | 7.8 kWh | 23.77 MWh per unit |
For our 3-unit installation: 3 × 23.77 = 71.31 MWh total throughput cap.
Once cumulative discharge reaches this figure the performance warranty expires, regardless of age.
To stay within the 10-year warranty window the battery must average no more than:
71,310 kWh ÷ (10 × 365 days) = 19.5 kWh/day discharge (all 3 units combined)
= 6.5 kWh/day per unit
= 0.83 equivalent full cycles/day per unit
The warranty cap is equivalent to 3,047 full discharge cycles per unit over the warranty period.
- Battery must be operated within the temperature and humidity ranges in the spec sheet.
- Installation must be by a skilled/trained installer following the installation guide.
- Remote firmware updates via internet connection are required; disconnection for extended periods may affect the full 10-year warranty (a 5-year floor still applies regardless).
- Warranty is transferable only if the equipment remains at the original installation address.
- Damage from improper installation or use
- Force majeure (lightning, flooding, fire, etc.)
- Cosmetic wear and tear
- Installations within 500 m of the coastline or affected by sea winds
- Damage from third-party software or components not supplied by Sigenergy
LFP (LiFePO4) is specifically designed for high-cycle daily use. It is far more tolerant of:
- Daily full charge/discharge cycles
- Being held at high SOC (less damaging than NMC chemistry)
- Shallow depth-of-discharge cycles
The 100% DoD test condition in the spec sheet confirms the manufacturer rates and tests at full depth — the controller's 40% SOC floor means real usage is shallower than the test, which is easier on the cells.
The 23.77 MWh/unit cap is the binding warranty constraint, not cycle count per se. The controller currently performs:
- Overnight grid charge to ~100% SOC (TOU mode)
- Pre-period headroom exports (discharge to ~40% SOC floor on Green days)
- Evening self-consumption discharge
- Optional pre-cheap-rate export discharge
On an active summer day this can drive 1.0–1.5+ equivalent cycles. Ireland's mixed weather (many Red/Amber/overcast days) averages the annual figure down considerably.
Run python scripts/battery_throughput.py to calculate the actual discharge rate from telemetry and project against the warranty cap.
| Metric | Value |
|---|---|
| Average daily discharge | 24.81 kWh/day (all 3 units) |
| Average per unit | 8.27 kWh/day (vs 7.8 kWh usable — >1 cycle/day) |
| Equivalent cycles/day | 1.06 per unit |
| Warranty daily budget | 19.5 kWh/day to hit cap exactly at year 10 |
| Summer overage vs budget | +27% above budget |
High-discharge days (30+ kWh) show the battery cycling from ~5–16% SOC up to 100% — effectively full depth-of-discharge cycles. The deep minimum SOC comes from self-powered mode naturally depleting the battery to cover home load overnight (the controller's 40% floor only applies to timed GRID_EXPORT windows, not self-powered operation).
Projection at measured rates:
- At summer rate only: warranty cap in 7.9 years (misses 10-year window)
- Blended estimate (winter = 40% of summer): 11.3 years ✓
- Blended estimate (winter = 60% of summer, more realistic without solar recharge): ~9.9 years ⚠
The winter assumption is the key uncertainty. In winter, solar recharging is absent so the battery can only do one full charge-discharge cycle per day (overnight TOU charge → daytime/evening self-powered discharge), but that single cycle is still substantial (~15–18 kWh) because the inverter will deplete the battery covering home load throughout the day.
The single largest lever is the pre-cheap-rate evening export — it adds a discharge cycle that isn't strictly necessary for solar headroom. Disabling or reducing it on days when morning forecast is not strongly Green would be the first thing to adjust.
The overnight grid charge to 100% followed immediately by a pre-period headroom export is also an avoidable cycle: if the morning forecast is Green, charging to a lower SOC overnight (e.g. 60%) would eliminate the export needed to create headroom. This would require a TOU schedule change in the Sigen app rather than controller code.