Dear Sir, I purchased a 4.8 Vcordless screwdriver and have a question about charging. It says to not leave it charging for more than 7 hours. If i do not plan to use it for several days do I just let it discharge and then charge it again before use or can I leave it in the charger hooked up all the time? Thanks, Walter Hoke phone- 979-776-0986 email- hoke_3@hotmail.com