How can I improve the readability of my Swift data formatting function?

I have the following function in Swift and am looking to improve the readability: Adding the variables to the Array below all of the let variables seems kind of funky to me and I was thinking maybe it would be good to declare an empty array above, get rid of the variable declarations and just add each value to the array but I'm not sure if that would be better or worse for performance. How can I improve the readability of this function without sacrificing performance?

func createFormattedDataStrings(deviceData: DeviceData, timeMilli: Double) -> Array<String?> {
        
        let formattedBmsVersion = (deviceData.bmsVersion?.first!.key)! + " \(deviceData.bmsVersion!.first!.value)"
        let formattedBoardVersion = (deviceData.boardVersion?.first!.key)! + " \(deviceData.boardVersion!.first!.value)"
        let formattedCellOne = (deviceData.cellOne?.first?.key)! + String(format: "%.2f", deviceData.cellOne!.first!.value) + "V"
        let formattedCellTwo = (deviceData.cellTwo?.first!.key)! + String(format: "%.2f", deviceData.cellTwo!.first!.value) + "V"
        let formattedCellThree = (deviceData.cellThree?.first!.key)! + String(format: "%.2f", deviceData.cellThree!.first!.value) + "V"
        let formattedCellFour = (deviceData.cellFour?.first!.key)! + String(format: "%.2f", deviceData.cellFour!.first!.value) + "V"
        let formattedCellFive = (deviceData.cellFive?.first!.key)! + String(format: "%.2f", deviceData.cellFive!.first!.value) + "V"
        let formattedCellSix = (deviceData.cellSix?.first!.key)! + String(format: "%.2f", deviceData.cellSix!.first!.value) + "V"
        let formattedCellSeven = (deviceData.cellSeven?.first!.key)! + String(format: "%.2f", deviceData.cellSeven!.first!.value) + "V"
        let formattedCellEight = (deviceData.cellEight?.first!.key)! + String(format: "%.2f", deviceData.cellEight!.first!.value) + "V"
        let formattedCellNine = (deviceData.cellNine?.first!.key)! + String(format: "%.2f", deviceData.cellNine!.first!.value) + "V"
        let formattedCellTen = (deviceData.cellTen?.first!.key)! + String(format: "%.2f", deviceData.cellTen!.first!.value) + "V"
        let formattedCellEleven = (deviceData.cellEleven?.first!.key)! + String(format: "%.2f", deviceData.cellEleven!.first!.value) + "V"
        let formattedCellTwelve = (deviceData.cellTwelve?.first!.key)! + String(format: "%.2f", deviceData.cellTwelve!.first!.value) + "V"
        let formattedCellThirteen = (deviceData.cellThirteen?.first!.key)! + String(format: "%.2f", deviceData.cellThirteen!.first!.value) + "V"
        let formattedCellFourteen = (deviceData.cellFourteen?.first!.key)! + String(format: "%.2f", deviceData.cellFourteen!.first!.value) + "V"
        let formattedPackVoltage = (deviceData.packVoltage?.first!.key)! + String(format: "%.1f", deviceData.packVoltage!.first!.value) + "V"
        let formattedPackSoc = (deviceData.packSoc?.first!.key)! + String(deviceData.packSoc!.first!.value) + "%"
        let formattedChargeTemp = (deviceData.chargeTemp?.first!.key)! + " \(deviceData.chargeTemp!.first!.value)°F"
        let formattedDischargeTemp = (deviceData.dischargeTemp?.first!.key)! + " \(deviceData.dischargeTemp!.first!.value)°F"
        let formattedChargeCurrent = (deviceData.chargeCurrent?.first!.key)! + " \(deviceData.chargeCurrent!.first!.value)A"
        let formattedChargeCircuitState = (deviceData.chargeCircuitState?.first!.key)! + " \(deviceData.chargeCircuitState!.first!.value)"
        let formattedDischargeCircuitState = (deviceData.dischargeCircuitState?.first!.key)! + " \(deviceData.dischargeCircuitState!.first!.value)"
        let formattedBalanceCircuitState = (deviceData.balanceCircuitState?.first!.key)! + " \(deviceData.balanceCircuitState!.first!.value)"
        let formattedEmptyCircuitState = (deviceData.emptyCircuitState?.first!.key)! + " \(deviceData.emptyCircuitState!.first!.value)"
        let formattedRestMode = deviceData.restMode
        let formattedMisbalancedMode = deviceData.misbalancedMode
        let formattedLeftChargedMode = deviceData.leftChargedMode
        let formattedHighVoltageMode = deviceData.highVoltageMode
        let formattedHighTempMode = deviceData.highTempMode
        let formattedLowTempMode = deviceData.lowTempMode
        let formattedLowVoltageMode = deviceData.lowVoltageMode
        let formattedHibernationMode = deviceData.hibernationMode
        let formattedOverDischargeMode = deviceData.overDischargeMode
        let formattedShipMode = deviceData.shipMode
        let formattedStateError = deviceData.stateError
        let formattedFinalCharge = deviceData.finalCharge
        let formattedFinalDischarge = deviceData.finalDischarge
        let formattedFinalBalance = deviceData.finalBalance
        let formattedFinalEmpty = deviceData.finalEmpty
        
        
        var dataStringArray: Array<String?> = [formattedBmsVersion, formattedBoardVersion, formattedCellOne, formattedCellTwo, formattedCellThree, formattedCellFour, formattedCellFive, formattedCellSix, formattedCellSeven, formattedCellEight, formattedCellNine, formattedCellTen, formattedCellEleven, formattedCellTwelve, formattedCellThirteen, formattedCellFourteen, formattedPackVoltage, formattedPackSoc, formattedChargeTemp, formattedDischargeTemp, formattedChargeCurrent, formattedChargeCircuitState, formattedDischargeCircuitState, formattedBalanceCircuitState, formattedEmptyCircuitState, formattedRestMode, formattedMisbalancedMode, formattedLeftChargedMode, formattedHighVoltageMode, formattedHighTempMode, formattedLowTempMode, formattedLowVoltageMode, formattedHibernationMode, formattedOverDischargeMode, formattedShipMode, formattedStateError, formattedFinalCharge, formattedFinalDischarge, formattedFinalBalance, formattedFinalEmpty]
        
        if (deviceData.bmsVersion?.first?.value)! >= 3634 {
            let formattedHotChargerMode = deviceData.hotChargerMode
            let formattedBadCharger = deviceData.badCharger
            dataStringArray.insert(formattedHotChargerMode!, at: 30)
            dataStringArray.insert(formattedBadCharger!, at: 41)
        }
        
        return dataStringArray
    }