Is the charger provided or do you need to buy one?
The charger is provided. The battery holds a charge for a decent amount of time. Even though originally bought for our 3-year old grandson (who actually does quite well on it under the watchful eyes of his sisters, our son-in-law, or our daughter) his sisters actually ride it more that he does. It bears the appearance of a properly made tractor that can offer numerous hours of enjoyment.
Does it come already assembled?
No, you can expect at least one hour on assembly.
Is the battery provided?
Yes it is. A charger is also provided. The first time that you charge the battery, you should do it for at least 18 hours to extend the life of the battery. My 3 year old son can play for about 4 hours and he is in love with it. The next time we charge it is usually 4 to 5 hours before using it. I love this John Deere ride on toys vehicle. I bought it for my 3 year old grandson. My husband helped him learn how to reverse and turn. He is now able to park it in the garage on his own. We have a slope in our front yard and he appears quite stable on it. He now drives it all over out yard with the cart loaded with toys. It has been quite helpful since we usually watch him for many hours.