PETFON Controller and Trackers use lithium rechargeable batteries. To recharge them, simply put them into a PETFON charger box (included in each pack)!
The lifespan of the battery is over 300 cycles (charges) at 100% capacity. Even after 300 charges, the battery should continue to function normally, but the capacity will begin to diminish. At around 500 charges the battery life should still be about 80%!