Two types of rechargeable solar batteries used in solar power bank: li-polymer battery and life PO4 battery. Life PO battery can stand higher temperature than li-polymer battery. But the cost is very high and MOQ is also high.
During usage, many customers like to put the solar charger in the car, then the temperature inside car and under glass would be very high in temp. So no matter what kind of batteries it is inside, we do not suggest to use this solar charger under high temp. condition.
Rechargeable solar batteries have an established temperature range for charging and for discharging. Most battery manufacturers recommend that users avoid charging the batteries in extreme weather conditions. They also recommend charging the batteries in moderate temperatures.
These batteries have the same energy capacity as lithium-ion batteries. The life cycle of both batteries are over 500 times. When sunshine is strong, it is easy to be fully charged.