How do you charge the battery of a sportster 883?

Just like the battery on any other vehicle, connect the charger's clips to the battery terminals, red to positive and black to negative.

However, because the Sportster has a relatively small battery, if charging at a high amperage (ten amps or more), it's important to monitor charging carefully unless the charger is fully automatic. Don't leave a small battery charging at a constant 10 amps overnight.

For peace of mind and foolproof charging, I recommend using a Battery Tender, which you can leave connected to the battery whenever the bike is parked. It cannot overcharge yet keeps the battery at full capacity.