Engineering report · reviewed against NEC 2026 & BS 7671:2018+A2
Engineering Breakdown: Running a BMW i4 / iX (Flexible Fast Charger 24A) on the Anker SOLIX F3800 Plus
When pairing the Anker SOLIX F3800 Plus (3,840 Wh LiFePO4 capacity, 6,000 W continuous, 9,000 W surge) with a BMW i4 / iX (Flexible Fast Charger 24A) (5,760 W running, 5,760 W starting surge), the system operates at 96% of continuous inverter capacity on a 240 V North American circuit and 92% on a 230 V UK/EU/AU circuit. At a 100% duty cycle and 85% inverter efficiency, a full battery delivers roughly 34 min of off-grid runtime. Wiring the connection over a 25 ft run calls for a 30 A breaker and 10 AWG copper, terminated at a NEMA 14-50P connection.
1. Compatibility Verdict & Inverter Load Utilization
In North American mode the BMW i4 / iX (Flexible Fast Charger 24A) loads the Anker SOLIX F3800 Plus's inverter to 96% of its 6,000 W continuous rating and 64% of its 9,000 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 | Anker SOLIX F3800 Plus provides | US/NA | UK/EU/AU |
|---|---|---|---|---|
| Continuous output | 5,760 W (5,520 W @ 230V) | 6,000 W | Pass | Pass |
| Start-up surge | 5,760 W | 9,000 W | Pass | Pass |
| Voltage | 240 V / 230 V | 120/240 V / 230 V | Pass | Pass |
| Connection | NEMA 14-50P | NEMA 14-50R / L14-30R / TT-30R | 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 5,760 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 20 A or less, which keeps the Anker SOLIX F3800 Plus at roughly 4,800 W. A full battery delivers about 2.9 kWh into the pack after inverter and on-board charger losses, worth roughly 10 miles (17 km) of driving at 3.5 mi/kWh.
As a portable power station, the Anker SOLIX F3800 Plus integrates the LiFePO4 battery, inverter, MPPT solar controller and AC outlets in one chassis, so it can be wheeled to the load or connected to a transfer switch through its NEMA 14-50R / L14-30R / TT-30R outlet.
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 3,840 Wh rating to about 3,264 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% | 1,440 W | 2.3 hrs | 34.6 kWh |
| 50% | 2,880 W | 1.1 hrs | 69.1 kWh |
| 65% | 3,744 W | 52 min | 89.9 kWh |
| 100% | 5,760 W | 34 min | 138.2 kWh |
Even at a 50% duty cycle the battery lasts 1.1 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: 5,760 W ÷ 240 V = 24.0 A, × 1.25 = 30.0 A, which rounds up to the next standard NEC 240.6 size of 30 A. The conductor must be protected by that breaker (75 °C ampacity at least 30 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) | 30 A | 10 AWG | 0.60% | Sized by ampacity |
| 50 ft (15.2 m) | 30 A | 10 AWG | 1.21% | Sized by ampacity |
| 75 ft (22.9 m) | 30 A | 10 AWG | 1.81% | Sized by ampacity |
| 100 ft (30.5 m) | 30 A | 10 AWG | 2.42% | 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 24.0 A (the EVSE's 24 A pilot current at 230 V), so a 25 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) | 25 A | 2.5 mm² | 1.16% |
| 15 m (49 ft) | 25 A | 2.5 mm² | 2.32% |
| 22.5 m (74 ft) | 25 A | 4.0 mm² | 2.16% |
| 30 m (98 ft) | 25 A | 4.0 mm² | 2.89% |
Because the current is modest, 10 AWG copper stays within the voltage-drop target all the way to 100 ft.
4. Solar Array Recharge Time Breakdown
The Anker SOLIX F3800 Plus accepts up to 3,200 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% |
|---|---|---|---|---|
| 400 W | 320 W | 12.0 hrs | 2.7 | −2,560 W |
| 800 W | 640 W | 6.0 hrs | 1.3 | −2,240 W |
| 1,600 W | 1,280 W | 3.0 hrs | 0.7 | −1,600 W |
| 3,000 W | 2,400 W | 1.6 hrs | 0.4 | −480 W |
| 3,200 W | 2,560 W | 1.5 hrs | 0.3 | −320 W |
A typical 800 W portable array refills the battery in about 6.0 hrs of strong sun, while maxing out the 3,200 W input cuts that to 1.5 hrs. To fully offset the BMW i4 / iX (Flexible Fast Charger 24A) at a 50% duty cycle (2,880 W average) during daylight you need roughly 3,600 W of panels, which exceeds this unit's 3,200 W input limit — solar can slow the drain but not eliminate it.
5. Frequently Asked Questions
Can the Anker SOLIX F3800 Plus run a BMW i4 / iX (Flexible Fast Charger 24A)?
Yes. The Anker SOLIX F3800 Plus delivers 6,000 W continuous and 9,000 W surge, covering the BMW i4 / iX (Flexible Fast Charger 24A)'s 5,760 W running and 5,760 W start-up draw at 96% inverter utilization, which is above the 80% guideline, so dedicate the unit to this load.
How many miles of range can the Anker SOLIX F3800 Plus add to a BMW i4 / iX?
A full 3,840 Wh charge delivers about 2.9 kWh to the vehicle battery after inverter (85%) and on-board charger (90%) losses — roughly 10 miles at 3.5 mi/kWh. At the full 5,760 W charge rate that takes 34 min.
What breaker and wire size do I need to connect a BMW i4 / iX (Flexible Fast Charger 24A) to the Anker SOLIX F3800 Plus?
In the US, 5,760 W at 240 V is 24.0 A; applying the NEC 125% continuous-load rule gives 30.0 A, so use a 30 A breaker and 10 AWG copper for runs up to 25 ft (0.6% voltage drop). In 230 V markets the load draws 24.0 A, protected by a 25 A MCB on 2.5 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 Anker SOLIX F3800 Plus with solar panels?
With an 800 W array and an 80% real-world harvest factor, a full recharge takes about 6.0 hrs of peak sun (1.3 days at 4.5 peak-sun-hours). At its maximum 3,200 W solar input it drops to 1.5 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.