Probable battery dead

Hello I have an Acton Blink S2(I know it is not a good board) and I haven’t charged it for one year. Now if i try to charghe it, the charger light becomes green(fully charghed) but when I turn on the skate it turns off immeditatly. I think the battery is dead, what could I do to verify this? Do I have to measure the voltage of the battery? Will a new battery solve the problem?