Answers:
You have a short in the bike, Ignition switch, light switch, bad cable??? To determine, work from a charged battery, disconnect the + cable and put multimeter between the battery post and the cable. Disconnect and connect wires until you find the leak.
Other Answers:
If it's only been a week since you replaced your battery, You have a problem with it's charging system. Look into that before you keep charging it up.
ditto tricle charger -- battery tender is only about 25 bucks -- go to www.denniskirk.com -- that would help alot but it sounds like you have a short some where OR have a bettery with a bad cell
I think I'd have to agree with the first two answers...
equal probability it has either a weak generator, or a parasitic drain...
put a multi meter across the battery terminals with the engine running... should be in excess of 13.2 volts...
if less, you have a weak generator...
check the ground cable... make sure both ends are clean and tight...
If you replaced the battery and it's weak again, then you have a problem with the charging system. Either the alternator isn't putting out enough voltage or the regulator/rectifier is bad. I don't know what year your bike is. The older Honda's had a separate regulator and rectifier. The newer ones have the two components combined into one unit. Depending on the year, the alternator's magnet is an electromagnet and is powered with brushes. If this is your model, then it might just need brushes. Another problem, with all models is the stator. Sound like a lot of mumbo-jumbo? Get a shop manual or take it to a shop.
Always include the year, make, engine size and model # when asking technical questions.