A charger is a charger and they all charge the same way! Use your car charger set to 12 volts. First, remove one of the cables from the battery or remove it from the bike, your choice. Hook your charger up to the battery and turn on the 10 amp charge for 15 minutes to warm the battery then reduce the charge to 2 amps. Let it charge over night and she is good to go! If the battery is still low on power, replace it.
Also if you have a wet battery, check every cell and make sure the fluid is up over the plates at least or up to the full mark.
Batteries don't like sitting unused for long periods of time. In the future, once a week or so put give her a 2 amp charge. A battery tender works great for keeping your battery in good shape.
Tuf I love ya and I don't want to argue, but chargers aren't chargers. There's many different varieties and tpes of chargers out there and they are designed for specific purposes and differ depending on the size of the battery.
A car charger could damage a bike battery. It may not. I would go with a charger specifically designed for the battery I'm charging. For a Busa, a Battery Tender, I have the Jr. ( need to use it )