Technology
The NODE-3 Platform
Physical hardware meets intelligent dispatch. A real, high-voltage battery installation executing automated, market-driven arbitrage.
Hardware Specifications
- ✔ 72 kWh Nominal Storage (3× Nissan e-NV200 second-life packs)
- ✔ FoxESS KH10.5 HV Hybrid Inverter (10.5 kW nominal output)
- ✔ G98 Single-Phase Connection (3.68 kWh/slot DNO cap, 32A export)
- ✔ LilyGo T-2CAN ESP32-S3 Bridge driving daisy-chained Yazaki SSRs
- ✔ Failsafe hardware loop tied to a latching IP67 physical E-stop
Software & Automation
- ⚡ LP-Optimal Dispatch: SciPy HiGHS linear programming solver
- ⚡ 48-Slot Rolling Forecast: Dynamic import/export optimization
- ⚡ Agile Arbitrage: Automatically targets cheapest slots to charge, highest to export
- ⚡ Homeowner Offset: Covers up to 12 kWh/day home consumption at zero cost
System Layout & Schematics
╔══════════════════════╗
║ FoxESS KH10.5 ║
║ HV Hybrid Inverter ║
╚══════╦═══════════════╝
║ HV DC (~360V) + CAN
┌─── CAN-B (isolated) ─────────╫────────┐
│ ║ │
│ ┌───────╨───────┐│
│ │ TOMZN DC 2P ││ ← MASTER isolator
│ │ 1100V 32A ││
│ └───────┬───────┘│
│ │ │
│ ┌───── +BUSBAR ──────────────────┐
│ │ (tinned Cu, 6×30mm × 200mm) │
│ │ │
│ ┌───┴───┐ ┌───┴───┐ ┌───┴───┐
│ │TOMZN │ │TOMZN │ │TOMZN │ ← branch protection
│ │2P 32A │ │2P 32A │ │2P 32A │
│ └───┬───┘ └───┬───┘ └───┬───┘
│ │ │ │
│ ╔═══╧═══╗ ╔═══╧═══╗ ╔═══╧═══╗
│ ║ SDP1 ║ ║ SDP2 ║ ║ SDP3 ║ ← Service Disconnect
│ ╚═══╤═══╝ ╚═══╤═══╝ ╚═══╤═══╝
│ │ │ │
│ ┌───┴───┐ ┌───┴───┐ ┌───┴───┐
│ │PACK 1 │ │PACK 2 │ │PACK 3 │
│ │ BMS+ │ │ BMS+ │ │ BMS+ │
│ │ INT. │ │ INT. │ │ INT. │
│ │ CONT. │ │ CONT. │ │ CONT. │
│ └─┬─┬─┬─┘ └─┬─┬───┘ └─┬─┬───┘
│ │ │ │ │ │ │ │
│ CAN │ │ │ Yazaki │ │ Yazaki │ │ Yazaki
│ ─────┘ │ │ ───────┘ │ ────────┘ │ ─────────
│ ┌───┘ │ │ │
│ │ │ ┌───────┴────────────┴───┐
│ │ │ │ DAISY-CHAINED signals: │
│ │ │ │ • BAT+IGN (Pin 1, 12V) │ ← via E-stop NC
│ │ │ │ • GND (Pin 2) │
│ │ │ │ • Precharge SSR1 OUT │
│ │ │ │ • +Contactor SSR2 OUT │
│ │ │ │ • −Contactor SSR3 OUT │
│ │ │ └────────────────────────┘
│ │ │
│ CAN-A │ │ Pack 1 only carries CAN
│ │ │
│ ┌──┴─────┴────┐
│ │ LilyGo │
│ │ T-2CAN │ GPIO 25 → SSR1 IN
│ │ ESP32-S3 │ GPIO 32 → SSR2 IN
│ │ (DALA) │ GPIO 33 → SSR3 IN
│ └─────────────┘
Physical Prototype Deployment
The live NODE-3 rig running inside an IP65 steel enclosure in Southampton. This unit acts as the primary hardware node, constantly feeding back telemetry and testing the limits of second-life grid interaction.
Through strict temperature controls, branch protection, and automated precharge sequences, the cell life of recycled Nissan EV packs is maximized while guaranteeing silent, domestic safety.