The charge light will not turn off when the batteries are fully charged. It is an indicator to show the fan is plugged in and the batteries are receiving a charge. You should not worry about over-charging the batteries, as all of our rechargeable products come with overcharge protection.
The batteries in the rechargeable fans can be changed by opening the battery cover and removing the batteries.
Our DL-713LS 40-LED lantern does not have a replaceable battery. The battery in this product should provide several years of use.
Make sure the plastic tab is removed from the battery. All new fans come with this installed to protect the battery in shipping. After removing the tab, fully charge the batteries.