pub fn current(&self) -> String {
        if self.enabled {
            match self.chart_type {
                ChartType::Voltage => format!("{:.2} {}", self.value_latest, volt::abbreviation()),
                ChartType::EnergyRate => format!("{:.2} {}", self.value_latest, watt::abbreviation()),
                ChartType::Temperature => match self.config.units() {
                    Units::Human => format!("{:.2} {}", self.value_latest, degree_celsius::abbreviation()),
                    Units::Si => format!("{:.2} {}", self.value_latest, kelvin::abbreviation()),
                },
            }
        } else {
            "NOT AVAILABLE".to_string()
        }
    }
Current value formatted with proper units
src/app/ui/chart.rs