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Reusing a BMW i3 22, 33 or 42 kWh HV battery pack (260–395 V nominal) with a SolaX X3 Hybrid G4 HV three-phase inverter. BMW i3 packs have excellent thermal management and robust NMC chemistry.
Short answer. A BMW i3 HV pack operates at 260–395 V DC and sits fully inside the SolaX X3 Hybrid G4 HV window of 90–800 V (three-phase) or 90–500 V (single-phase X1 Hybrid G4 HV). The BMS-EV controller emulates a Pylontech HV-series pack on the SolaX BMS CAN bus, which SolaX accepts natively. Every BMW i3 voltage state fits.
| Inverter | DC input range | Power | Phase | Notes |
|---|---|---|---|---|
| SolaX X3 Hybrid G4 5.0 HV | 90–800 V | 5 kW | Three-phase | Full i3 range fits |
| SolaX X3 Hybrid G4 6.0 HV | 90–800 V | 6 kW | Three-phase | Full i3 range fits |
| SolaX X3 Hybrid G4 8.0 HV | 90–800 V | 8 kW | Three-phase | Full i3 range fits |
| SolaX X3 Hybrid G4 10.0 HV | 90–800 V | 10 kW | Three-phase | Full i3 range fits |
| SolaX X3 Hybrid G4 12.0 HV | 90–800 V | 12 kW | Three-phase | Full i3 range fits |
| SolaX X3 Hybrid G4 15.0 HV | 90–800 V | 15 kW | Three-phase | Full i3 range fits |
| SolaX X1 Hybrid G4 HV 5.0 | 90–500 V | 5 kW | Single-phase | Full i3 range fits (395 V < 500 V) |
| SolaX X1 Hybrid G4 HV 7.5 | 90–500 V | 7.5 kW | Single-phase | Full i3 range fits |
BMW i3 pack voltages across SoC (96s cell configuration):
| SoC | Voltage (approx.) |
|---|---|
| 0% (cutoff, 2.7 V/cell) | ~260 V |
| 20% | ~330 V |
| 50% (nominal, 3.65 V/cell) | ~355 V |
| 100% (4.1 V/cell) | ~395 V |
The full 260–395 V BMW i3 range fits inside the SolaX X3 Hybrid G4 HV 90–800 V window with over 400 V of headroom above 100% SoC and 170 V below 0%. On the single-phase X1 Hybrid G4 HV (90–500 V), the i3 peak of ~395 V leaves 105 V of headroom.
SolaX X-Hybrid G4 inverters accept a Pylontech HV-series CAN protocol on the BMS-CAN port at 500 kbps. The BMS-EV controller emulates this protocol:
On the SolaX display menu, select battery type: Pylontech HV or T-BAT-H depending on firmware version.
Engineering values below are examples. Final conductor cross-section and protective-device sizing must be calculated for the actual pack, maximum current, cable length, installation method, ambient temperature and applicable local standards (IEC 60364-7-712, VDE-AR-N 4105, NEC 690).
The 33 kWh (94 Ah) is the sweet spot — highest availability, prices around €1 800–€3 200, and 25–29 kWh usable capacity even after typical SoH degradation.
Not directly. Parallel HV packs must be voltage-matched to ~2 V before contactor close, which is hard with two independent BMWs. For >42 kWh, use two SolaX inverters with independent packs, or a single Tesla LR pack.
Pylontech HV (or T-BAT-H on newer firmware). The BMS-EV controller is factory-configured to match; check your invoice for the exact SolaX menu setting.
Yes — the X1 Hybrid G4 HV (90–500 V single-phase) accepts the full i3 range. For homes with three-phase supply, the X3 series is preferred.
No. BMS-EV emulates the CAN messages BMW's vehicle side would normally send. INPA / ISTA is only needed to read pack SoH before purchase — not for operation.
Estimates are 8–15 years given the low cycling depth (typically 20–80% daily) compared to vehicle use. BMW i3 cells are Samsung SDI prismatic and are among the most durable NMC formats in the industry.
Yes. All SolaX X3 Hybrid G4 HV inverters have an EPS output that continues to draw from the i3 pack during grid outages, sized to the discharge limit BMS-EV reports.
Below 70% SoH the capacity and continuous power drop enough that a newer battery is usually a better investment. 75–85% SoH is typical for a 6–8-year-old i3 and is well suited to stationary duty.