What types of battery does OUPES use?

LiFePO4 - The Battery is estimated to have over 80% of your original capacity after 3500 cycles, with a gradual reduction after that. (Note: this doesn't mean the battery only has a 3500 cycle life span. It means that up until 3500 cycles, the unit can perform at its best. However, due to battery degradation there will be a gradual decline in performance after 3500 cycles.)
It has 6 times of longer lifespan than ordinary lithium batteries. LiFePO4 battery is much safer, more stable and more eco-friendly with no heavy metal elements that are harmful to people.