Features: 1.Battery type electricity quantity display 2.Wide application fields:lithium battery 3.Using Method:connect display board positive and negative port with tested battery positive and negative port,digital tube will display real-time battery electricity quantity 4.Digital Color:outline red,display block blue (when battery electricity quantity is full,it will be all on) Display Electricity Quantity Parameter: 1.When battery voltage is over N*3.3V,it will illuminate 1 block electricity quantity (note:N represents battery quantity) 2.When battery voltage is over N*3.5V,it will illuminate 2 blocks electricity quantity 3.When battery voltage is over N*3.7V,it will illuminate 3 blocks electricity quantity 4.When battery voltage is over N*3.9V,it will illuminate 4 blocks electricity quantity 5.When battery voltage is less than N*3.3V,4 blocks display will be off;it represents battery is less than 3.3V,and you can charge the battery