Charger light staying green

My magsafe charger light stays green, the battery is dead and my laptop has been "worthless" for quite a while. I took it to an authorized repair shop, and he told me it was the logic board. I have since bought a new mac, but would love to get the laptop going again. I read where someone had luck trying a new battery, and I got thinking that maybe a freshly charged battery would work? I don't have access to one, but my question is if I bought a separate battery charger to charge the batteries, I wonder if the macbook would work?