How to properly charge my motorcycle battery?

I have a Yuasa motorcycle battery for a 750 street bike. The bike sat in my heated garage during winter, about 4-5 months without being started. The battery lost it's charge, and I wanted to charge it up using a 2 amp charger. I tried doing 4-5 hour charge intervals once a day, which would give it enough juice to start the bike and idle as long as I wanted. But when I would try to start it a second time, it would barely turn over. Now should I be charging more than 5 hours, or is my battery toast? I would appreciate an answer in "english" since about 99/100 times I've searched for help, the question involves too much info about the science and history of battery charging. Thanks.

2 amps is the correct size charger for a battery this size.
Before you charge it, make sure that the battery has electrolyte in it. Most bike batteries are translucent, so you can see the fluid level inside the battery. If it's low, add "distilled" water to the battery, no acid. Charge the battery for 24 hours out of the bike on a piece of wood or thick cardboard, but not on the concrete. Believe it or not, concrete will suck the charge from a battery. Don't know how, but it does.
How old is the battery? If it's more than 3 years old, I'd just replace it and then go ride.

If you have tried to charge it a couple of times and it still loses its power it looks like it is K*******D this can happen some times even if the bike has been run, it is advisable to remove the battery from the bike if it not being used and overwintered even in a warm garage.

Like others stated slow charge would be the best, if you put it on fast charge it could boil the electrolyte and cause it to get low,where it wouldnt have as much electrolyte liquid to hold charge, then it would have to be replaced.Usually with the slow charge will take about 8hrs minimum.GL

charge it overnight

using a 2amp charger it may take up to 8hrs to get a full charge. leave the charger on overnight. if the battery doesn't hold a charge than it is probly "toast" or it may be the alternator on the bike that may be bad. If all else fails take the battery to an auto parts store. They will put it on their machine that will tell if the battery is OK or needs replacement.

Use a proper 3 stage charger so you don't have to worry about overcharging. I have a 10AMP 3 Stage charger which does wonders to all the batteries in my cars and Bikes.

3 Stage meaning:

1st - it checks if battery is faulty or not before the initial bulk charge (or something like that)
2nd - it goes on absorption charge to 80% and levels to 100%
3rd - it maintains 100% the charge until battery is ready for use.

Feature offers prevention of overcharging so you can sleep at night. I suggest you buy the expensive ones as they are expensive for this reason!

I have personally left (and still do) forget a battery is charging for 24hours with my 3 stage charger and the batteries still works fine. These chargers a built for this reason, so you can plug it in without taking the battery off your vehicles; charge it and don't worry about it.

One more thing: If your charger is more than 1.2 Amp, then remove the battery from the motorcycle to charge it.

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It might not be your battery that's toast. You need a multimeter and a Clymer manual. The Clymer manual will tell you how to use the multimeter to check your regulator, rectifier, and stator without taking your bike all apart.