// BMS Simulation
    useEffect(() => {
        const timer = setInterval(() => {
            setAgvState(s => {
                const isCharging = s.isCharging;
                let newLevel = s.batteryLevel;

                if (isCharging) {
                    // Charge: 1% per min (faster than discharge)
                    newLevel = Math.min(100, s.batteryLevel + (1.0 / 60)); 
                } else {
                    // Discharge: 5% per 10 min = 0.5% per min = 0.5 / 60 per sec
                    newLevel = Math.max(0, s.batteryLevel - (0.5 / 60));
                }

                // Fluctuate Voltages (+- 0.01V)
                const newVoltages = s.cellVoltages.map(v => {
                    const delta = (Math.random() - 0.5) * 0.02; 
                    let val = v + delta;
                    if (val < 2.8) val = 2.8;
                    if (val > 3.6) val = 3.6;
                    return val;
                });

                return {
                    ...s,
                    batteryLevel: newLevel,
                    cellVoltages: newVoltages
                };
            });
        }, 1000);
        return () => clearInterval(timer);
    }, []);