Engineering report · reviewed against NEC 2026 & BS 7671:2018+A2
Engineering Breakdown: Running a Kia EV9 (32A Level 2 EV Charger) 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 Kia EV9 (32A Level 2 EV Charger) (7,680 W running, 7,680 W starting surge), the system operates at 100% of continuous inverter capacity on a 240 V North American circuit and 96% on a 230 V UK/EU/AU circuit. At a 100% duty cycle and 85% inverter efficiency, a full battery delivers roughly 1.1 hrs of off-grid runtime. Wiring the connection over a 25 ft run calls for a 40 A breaker and 8 AWG copper, terminated at a NEMA 14-50P connection.
1. Compatibility Verdict & Inverter Load Utilization
In North American mode the Kia EV9 (32A Level 2 EV Charger) loads the Enphase IQ Battery 5P (Dual 10kWh Bank)'s inverter to 100% of its 7,680 W continuous rating and 50% 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 | US/NA | UK/EU/AU |
|---|---|---|---|---|
| Continuous output | 7,680 W (7,360 W @ 230V) | 7,680 W | Pass | Pass |
| Start-up surge | 7,680 W | 15,360 W | Pass | Pass |
| Voltage | 240 V / 230 V | 120/240 V / 230 V | Pass | Pass |
| Connection | NEMA 14-50P | Hardwired IQ System Controller | UK/EU/AU: Type 2 EVSE · IEC 60309 32A Commando | |
An EVSE is a constant-current device: the vehicle draws exactly the current advertised by the J1772/NACS pilot signal, so the 7,680 W figure is both the running load and the start-up load — there is no motor inrush. That makes the calculation unusually clean. If you want to stay under the 80% sustained-load guideline, set the charge current in the vehicle app to 25 A or less, which keeps the Enphase IQ Battery 5P (Dual 10kWh Bank) at roughly 6,000 W. A full battery delivers about 7.7 kWh into the pack after inverter and on-board charger losses, worth roughly 27 miles (43 km) of driving at 3.5 mi/kWh.
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% | 1,920 W | 4.4 hrs | 46.1 kWh |
| 50% | 3,840 W | 2.2 hrs | 92.2 kWh |
| 65% | 4,992 W | 1.7 hrs | 119.8 kWh |
| 100% | 7,680 W | 1.1 hrs | 184.3 kWh |
Even at a 50% duty cycle the battery lasts 2.2 hrs, so plan on solar, grid or generator recharging for anything longer than an evening outage.
3. NEC 125% Breaker & Copper Wire Gauge Sizing
NEC 210.19(A) and 210.20(A) require conductors and overcurrent devices for continuous loads — anything running three hours or more, which includes EV charging and HVAC — to be rated at 125% of the load current. For this pairing: 7,680 W ÷ 240 V = 32.0 A, × 1.25 = 40.0 A, which rounds up to the next standard NEC 240.6 size of 40 A. The conductor must be protected by that breaker (75 °C ampacity at least 40 A) and keep round-trip voltage drop at or below 3%, so longer runs are upsized.
Voltage drop % = (2 × L × I × R) ÷ V × 100
North America (NEC, THHN copper, 75 °C)
| One-way distance | Breaker | Min. copper | Voltage drop | Note |
|---|---|---|---|---|
| 25 ft (7.6 m) | 40 A | 8 AWG | 0.51% | Sized by ampacity |
| 50 ft (15.2 m) | 40 A | 8 AWG | 1.02% | Sized by ampacity |
| 75 ft (22.9 m) | 40 A | 8 AWG | 1.53% | Sized by ampacity |
| 100 ft (30.5 m) | 40 A | 8 AWG | 2.04% | Sized by ampacity |
UK / EU / Australia (IEC 60364 / BS 7671, PVC copper, method C)
IEC-based codes size protection by design current rather than a blanket 125% multiplier: Ib ≤ In ≤ Iz. At 230 V the load draws 32.0 A (the EVSE's 32 A pilot current at 230 V), 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 | 0.96% |
| 15 m (49 ft) | 32 A | 4.0 mm² | 1.92% |
| 22.5 m (74 ft) | 32 A | 4.0 mm² | 2.89% |
| 30 m (98 ft) | 32 A | 6.0 mm² | 2.57% |
Because the current is modest, 8 AWG copper stays within the voltage-drop target all the way to 100 ft.
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 | −3,200 W |
| 1,600 W | 1,280 W | 7.8 hrs | 1.7 | −2,560 W |
| 3,000 W | 2,400 W | 4.2 hrs | 0.9 | −1,440 W |
| 6,000 W | 4,800 W | 2.1 hrs | 0.5 | +960 W |
| 12,000 W | 9,600 W | 1.0 hrs | 0.2 | +5,760 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 Kia EV9 (32A Level 2 EV Charger) at a 50% duty cycle (3,840 W average) during daylight you need roughly 4,800 W of panels, which this unit can accept.
5. Frequently Asked Questions
Can the Enphase IQ Battery 5P (Dual 10kWh Bank) run a Kia EV9 (32A Level 2 EV Charger)?
Yes. The Enphase IQ Battery 5P (Dual 10kWh Bank) delivers 7,680 W continuous and 15,360 W surge, covering the Kia EV9 (32A Level 2 EV Charger)'s 7,680 W running and 7,680 W start-up draw at 100% 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 Kia EV9?
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 7,680 W charge rate that takes 1.1 hrs.
What breaker and wire size do I need to connect a Kia EV9 (32A Level 2 EV Charger) to the Enphase IQ Battery 5P (Dual 10kWh Bank)?
In the US, 7,680 W at 240 V is 32.0 A; applying the NEC 125% continuous-load rule gives 40.0 A, so use a 40 A breaker and 8 AWG copper for runs up to 25 ft (0.5% voltage drop). In 230 V markets the load draws 32.0 A, protected by a 32 A MCB on 4.0 mm² cable for runs up to 7.5 m. Receptacle: NEMA 14-50P (US) or Type 2 EVSE · IEC 60309 32A Commando (UK/EU/AU).
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.