A device including: a rechargeable battery; a data store; a battery monitoring system configured to: record battery deterioration events to the data store, wherein the battery deterioration events include a number of charge and discharge cycles of the battery and whether the charge and discharge cycles of the battery were full or partial; record usage habits of using of the device to the data store, wherein the usage habits include how often the battery is charged on average and an amount that the battery is discharged before being charged; and predict an amount of time of remaining battery life based on the deterioration events and the usage habits; and determine an approximation of deterioration of capacity of the battery; and a display device configured to display: an indication of amount of time of remaining battery life; and an image that includes: a first representation of an original capacity of the battery, a second representation of the approximation of the amount of deterioration of the battery capacity relative to the first representation, a third representation of the remaining capacity of the battery relative to the first representation, and a fourth representation of the present charge of the battery relative to the third representation. a rechargeable battery; a data store; a battery monitoring system configured to: record battery deterioration events to the data store, wherein the battery deterioration events include a number of charge and discharge cycles of the battery and whether the charge and discharge cycles of the battery were full or partial; record usage habits of using of the device to the data store, wherein the usage habits include how often the battery is charged on average and an amount that the battery is discharged before being charged; and predict an amount of time of remaining battery life based on the deterioration events and the usage habits; and determine an approximation of deterioration of capacity of the battery; and record battery deterioration events to the data store, wherein the battery deterioration events include a number of charge and discharge cycles of the battery and whether the charge and discharge cycles of the battery were full or partial; record usage habits of using of the device to the data store, wherein the usage habits include how often the battery is charged on average and an amount that the battery is discharged before being charged; and predict an amount of time of remaining battery life based on the deterioration events and the usage habits; and determine an approximation of deterioration of capacity of the battery; and a display device configured to display: an indication of amount of time of remaining battery life; and an image that includes: a first representation of an original capacity of the battery, a second representation of the approximation of the amount of deterioration of the battery capacity relative to the first representation, a third representation of the remaining capacity of the battery relative to the first representation, and a fourth representation of the present charge of the battery relative to the third representation. an indication of amount of time of remaining battery life; and an image that includes: a first representation of an original capacity of the battery, a second representation of the approximation of the amount of deterioration of the battery capacity relative to the first representation, a third representation of the remaining capacity of the battery relative to the first representation, and a fourth representation of the present charge of the battery relative to the third representation.