<p>The Efest LUC BLU4 is a 4 Slot lithium li-ion battery charger with Bluetooth connectivity. Connect to the charger via the Efest app and monitor the status of each battery with your smart phone! This charger is compatible with most types of cylindrical lithium batteries ranging in size from 10440 to 18650.</p><p><br></p><h4><b>Features</b></h4><p><br></p><ul><li><p>Intelligent lithium ion battery charger with Bluetooth connectivity</p></li></ul><ul><li><p>Digital LCD display with rotating charging indicators for each channel</p></li></ul><ul><li><p>Compatible with most sizes of cylindrical lithium-ion batteries ranging from 10440 to 18650</p></li></ul><ul><li><p>Automatically detects battery power status and selects the appropriate voltage and charge mode</p></li></ul><ul><li><p>Automatically stops when charging is complete and prevents batteries from being over-charged</p></li></ul><ul><li><p>Features reverse polarity protection if you accidentally insert a battery the wrong way</p></li></ul><p><br></p><p><br></p>