how to make slots output different responses

Doing some smart home skill development and my Intent utterance is "how long until my battery is {state}" State being either empty or full. I know I could do this with different intents but I wont want to have two many intents as I already have many. I basically want the user to say either full or empty in place of {state}. and then from there, depending on their answer, give different answers for full or empty. I haven't found much online so i hope you guys can help. Im also new to code.

You should create a slot for your battery state:

{
  "name": "BatteryState",
  "values": [
      {
          "id": "empty",
          "name": {
              "value": "empty"
          }
      },
      {
          "id": "full",
          "name": {
              "value": "full"
          }
      }
  ]
}

You can create it by yourself in the UI or paste in types collection in JSON editor.

Then use created slot in your intent

{
  "name": "BatteryStateIntent",
  "slots": [
      {
          "name": "batteryState",
          "type": "BatteryState"
      }
  ],
  "samples": [
      "how long until my battery is {batteryState}"
  ]
}

You can create it by yourself in the UI or paste in intents collection in JSON editor.

Then in the code:

const BatteryStateIntentHandler = {
  canHandle(handlerInput) {
    return (
      Alexa.getRequestType(handlerInput.requestEnvelope) === "IntentRequest" &&
      Alexa.getIntentName(handlerInput.requestEnvelope) === "BatteryStateIntent"
    );
  },
  handle(handlerInput) {
    const batteryStatus =
      handlerInput.requestEnvelope.request.intent.slots.batteryState.value;
    let speakOutput = "";
    if (batteryStatus === "full") {
      const timeToFull = 10; // or some sophisticated calculations ;)
      speakOutput += `Your battery will be full in ${timeToFull} minutes!`;
    } else if (batteryStatus === "empty") {
      const timeToEmpty = 5; // or some sophisticated calculations ;)
      speakOutput += `Your battery will be full in ${timeToEmpty} minutes!`;
    } else {
      speakOutput += "I don't know this status";
    }

    return handlerInput.responseBuilder
      .speak(speakOutput)
      .reprompt(speakOutput)
      .getResponse();
  },
};

Make sure you used the same intent name as in the builder. And at the end, add created intent handler to request handlers:

exports.handler = Alexa.SkillBuilders.custom()
  .addRequestHandlers(
    BatteryStateIntentHandler,
    // ...
  )
  .lambda();