Just make sure if it is the alternator(have it tested at a shop, usually free of charge) make sure you get a new alternator instead of a rebuild. ANd try avoiding draing the good battery. Its bad enough the alternator is going out, no need to buy an extra battery.
"Any fool can criticize, condemn and complain - and most fools do. But it takes character and self-control
to be understanding and forgiving. A great man shows his greatness, by the way he treats little men."