Mart79

Hi guys, Eventually got round to buying a charger for the Ryobi one Hand vac that has been sat on a shelf since it was bought a good few months ago. Anyway, after plugging the battery in, the red light flashes for a few seconds then it turns green, thus indicating the battery is fully charged according to the instructions (I can assure you the battery is completely dead). I have connected the battery to a multimeter and this only shows 6v (the battery is 18v) so following a little research on Google I come across something that states if the battery is fully discharged it can enter a sleep mode and needs ‘mini charges’ to recover. Is this true or am I likely to just waste my time in attempting it? (It states ‘plug battery in for 2-3 seconds to recover from sleep mode, it can take upto 30 mins’