An infusion device comprising: a rechargeable battery having a gas gauge integrated circuit ("IC"); one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the one or more processors to: at least one of receive or determine, at predetermined intervals of time in real-time, measurements comprising: a voltage of the rechargeable battery, a change in the voltage over the predetermined interval of time, an average current associated with the rechargeable battery, a temperature of the rechargeable battery, and a remaining voltage or capacity reported by the gas gauge IC, generate a feature vector comprising the voltage, the change in the voltage, the average current, the temperature, the remaining voltage or capacity reported by the gas gauge IC, and a full charge voltage or capacity of the rechargeable battery, apply the feature vector to a trained neural network to determine an actual remaining voltage or capacity of the rechargeable battery, wherein the trained neural network comprises weight factors and biases for calculating a plurality of paths through a plurality of layers, and generate, in real-time, an alarm indicating that the actual remaining voltage or capacity of the rechargeable battery is below a predetermined threshold when the actual remaining voltage or capacity of the rechargeable battery is below the predetermined threshold. a rechargeable battery having a gas gauge integrated circuit ("IC"); one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the one or more processors to: at least one of receive or determine, at predetermined intervals of time in real-time, measurements comprising: a voltage of the rechargeable battery, a change in the voltage over the predetermined interval of time, an average current associated with the rechargeable battery, a temperature of the rechargeable battery, and a remaining voltage or capacity reported by the gas gauge IC, generate a feature vector comprising the voltage, the change in the voltage, the average current, the temperature, the remaining voltage or capacity reported by the gas gauge IC, and a full charge voltage or capacity of the rechargeable battery, apply the feature vector to a trained neural network to determine an actual remaining voltage or capacity of the rechargeable battery, wherein the trained neural network comprises weight factors and biases for calculating a plurality of paths through a plurality of layers, and generate, in real-time, an alarm indicating that the actual remaining voltage or capacity of the rechargeable battery is below a predetermined threshold when the actual remaining voltage or capacity of the rechargeable battery is below the predetermined threshold. at least one of receive or determine, at predetermined intervals of time in real-time, measurements comprising: a voltage of the rechargeable battery, a change in the voltage over the predetermined interval of time, an average current associated with the rechargeable battery, a temperature of the rechargeable battery, and a remaining voltage or capacity reported by the gas gauge IC, a voltage of the rechargeable battery, a change in the voltage over the predetermined interval of time, an average current associated with the rechargeable battery, a temperature of the rechargeable battery, and a remaining voltage or capacity reported by the gas gauge IC, generate a feature vector comprising the voltage, the change in the voltage, the average current, the temperature, the remaining voltage or capacity reported by the gas gauge IC, and a full charge voltage or capacity of the rechargeable battery, apply the feature vector to a trained neural network to determine an actual remaining voltage or capacity of the rechargeable battery, wherein the trained neural network comprises weight factors and biases for calculating a plurality of paths through a plurality of layers, and generate, in real-time, an alarm indicating that the actual remaining voltage or capacity of the rechargeable battery is below a predetermined threshold when the actual remaining voltage or capacity of the rechargeable battery is below the predetermined threshold.