Engineering report · reviewed against NEC 2026 & BS 7671:2018+A2
Engineering Breakdown: Running a BYD Atto 3 / Dolphin (7kW AC Charging) on the Enphase IQ Battery 5P (Dual 10kWh Bank)
When pairing the Enphase IQ Battery 5P (Dual 10kWh Bank) (10,000 Wh LiFePO4 capacity, 7,680 W continuous, 15,360 W surge) with a BYD Atto 3 / Dolphin (7kW AC Charging) (7,200 W running, 7,200 W starting surge), the system operates at 94% of continuous inverter capacity on a 230 V UK/EU/AU circuit. At a 100% duty cycle and 85% inverter efficiency, a full battery delivers roughly 1.2 hrs of off-grid runtime. Wiring the connection over a 7.5 m run calls for a 32 A MCB and 4.0 mm² copper, terminated at a Type 2 EVSE · IEC 60309 32A Commando connection.
1. Compatibility Verdict & Inverter Load Utilization
In UK/EU/AU 230 V mode the BYD Atto 3 / Dolphin (7kW AC Charging) loads the Enphase IQ Battery 5P (Dual 10kWh Bank)'s inverter to 94% of its 7,680 W continuous rating and 47% of its 15,360 W surge rating. The pairing works, but running above 80% for hours raises internal temperatures and fan noise, and leaves little room for other loads. Treat it as a dedicated circuit.
| Check | Load requires | Enphase IQ Battery 5P provides | UK/EU/AU |
|---|---|---|---|
| Continuous output | 7,200 W | 7,680 W | Pass |
| Start-up surge | 7,200 W | 15,360 W | Pass |
| Voltage | 230 V | 230 V | Pass |
| Connection | Type 2 EVSE · IEC 60309 32A Commando | Hardwired consumer unit (RCBO protected) |
This is a 230 V market charging profile: the 7,200 W figure is the single-phase Type 2 (IEC 62196) rate of 31 A × 230 V. EV supply equipment is a constant-current load with no start-up surge, so the inverter only has to sustain the set current. To stay under the 80% sustained-load guideline, cap the charge current at 26 A in the vehicle or charger app, which holds the Enphase IQ Battery 5P (Dual 10kWh Bank) near 5,980 W. In the UK, a charge point must meet BS 7671 Section 722 and the Electric Vehicles (Smart Charge Points) Regulations; in Australia and New Zealand, AS/NZS 3000 Section 7 and local network limits apply. A full battery puts about 7.7 kWh into the pack after losses — roughly 43 km (27 miles) of range.
The Enphase IQ Battery 5P (Dual 10kWh Bank) is a permanently installed hybrid battery. It sits behind a gateway or system controller, so loads are fed from the home's own panel rather than from outlets on the unit.
2. Real-World Runtime by Duty Cycle
Nameplate capacity is not usable capacity. DC-to-AC conversion, battery management overhead and cell protection reduce the 10,000 Wh rating to about 8,500 Wh of deliverable AC energy (85% system efficiency). EV charging runs at a fixed current, so the 100% row is the realistic figure; lower rows apply only if you schedule charging in intervals.
| Duty cycle | Average draw | Runtime (no solar) | Energy per 24 h |
|---|---|---|---|
| 25% | 1,800 W | 4.7 hrs | 43.2 kWh |
| 50% | 3,600 W | 2.4 hrs | 86.4 kWh |
| 65% | 4,680 W | 1.8 hrs | 112.3 kWh |
| 100% | 7,200 W | 1.2 hrs | 172.8 kWh |
Even at a 50% duty cycle the battery lasts 2.4 hrs, so plan on solar, grid or generator recharging for anything longer than an evening outage.
3. BS 7671 / IEC 60364 Breaker & Cable Sizing
IEC-based codes size protection by design current rather than a blanket 125% multiplier: Ib ≤ In ≤ Iz. At 230 V the load draws 31.3 A, so a 32 A Type B/C MCB with RCD protection applies. In the UK, BS 7671 Section 722 additionally requires a dedicated circuit and Type A or Type B RCD for EV charge points.
| One-way distance | MCB | Min. cable | Voltage drop |
|---|---|---|---|
| 7.5 m (25 ft) | 32 A | 4.0 mm² | 0.94% |
| 15 m (49 ft) | 32 A | 4.0 mm² | 1.88% |
| 22.5 m (74 ft) | 32 A | 4.0 mm² | 2.82% |
| 30 m (98 ft) | 32 A | 6.0 mm² | 2.52% |
Moving the Enphase IQ Battery 5P (Dual 10kWh Bank) from 7.5 m to 30 m away forces the conductor up from 4.0 mm² to 6.0 mm² — park the unit as close to the load as ventilation and weather protection allow.
4. Solar Array Recharge Time Breakdown
The Enphase IQ Battery 5P (Dual 10kWh Bank) accepts up to 12,000 W of photovoltaic input. Real arrays rarely deliver nameplate output, so we apply an 80% harvest factor for MPPT conversion, cell temperature and soiling, and convert hours to days using 4.5 peak-sun-hours — a conservative annual average for the US, southern Europe and Australia (UK winters can fall below 1.5).
| PV array | Real harvest | 0–100% recharge | Sun-days @ 4.5 PSH | Net with load @ 50% |
|---|---|---|---|---|
| 800 W | 640 W | 15.6 hrs | 3.5 | −2,960 W |
| 1,600 W | 1,280 W | 7.8 hrs | 1.7 | −2,320 W |
| 3,000 W | 2,400 W | 4.2 hrs | 0.9 | −1,200 W |
| 6,000 W | 4,800 W | 2.1 hrs | 0.5 | +1,200 W |
| 12,000 W | 9,600 W | 1.0 hrs | 0.2 | +6,000 W |
A typical 800 W portable array refills the battery in about 15.6 hrs of strong sun, while maxing out the 12,000 W input cuts that to 1.0 hrs. To fully offset the BYD Atto 3 / Dolphin (7kW AC Charging) at a 50% duty cycle (3,600 W average) during daylight you need roughly 4,500 W of panels, which this unit can accept.
5. Frequently Asked Questions
Can the Enphase IQ Battery 5P (Dual 10kWh Bank) run a BYD Atto 3 / Dolphin (7kW AC Charging)?
Yes. The Enphase IQ Battery 5P (Dual 10kWh Bank) delivers 7,680 W continuous and 15,360 W surge, covering the BYD Atto 3 / Dolphin (7kW AC Charging)'s 7,200 W running and 7,200 W start-up draw at 94% inverter utilization, which is above the 80% guideline, so dedicate the unit to this load.
How many miles of range can the Enphase IQ Battery 5P (Dual 10kWh Bank) add to a BYD Atto 3 / Dolphin?
A full 10,000 Wh charge delivers about 7.7 kWh to the vehicle battery after inverter (85%) and on-board charger (90%) losses — roughly 27 miles at 3.5 mi/kWh. At the full 7,200 W charge rate that takes 1.2 hrs.
What breaker and wire size do I need to connect a BYD Atto 3 / Dolphin (7kW AC Charging) to the Enphase IQ Battery 5P (Dual 10kWh Bank)?
At 230 V the load draws 31.3 A. Under BS 7671 / IEC 60364 the protective device must be at least the design current (Ib ≤ In ≤ Iz), so use a 32 A MCB with RCD protection on 4.0 mm² copper cable for runs up to 7.5 m (0.9% voltage drop). Connection: Type 2 EVSE · IEC 60309 32A Commando.
How long does it take to recharge the Enphase IQ Battery 5P (Dual 10kWh Bank) with solar panels?
With an 800 W array and an 80% real-world harvest factor, a full recharge takes about 15.6 hrs of peak sun (3.5 days at 4.5 peak-sun-hours). At its maximum 12,000 W solar input it drops to 1.0 hrs.
Methodology & safety note
Specifications come from manufacturer datasheets in our open dataset; ampacity and resistance values follow NEC Table 310.16 and Chapter 9 Table 8, and BS 7671 Appendix 4. Calculations assume copper conductors, 30 °C ambient and no bundling derating. Inverter-to-panel connections require a listed transfer switch or interlock to prevent back-feeding the grid. These results are an engineering estimate, not a substitute for a licensed electrician and local permit. See our methodology and safety disclaimer.