still applies. or a DC clamp meter and that will allow you to not have to pull the cables off, simply clamp it around the + battery lead and watch it. I use this one and it works flawlessly.

 

Take the battery to Batteries Plus, Auto Zone, etc. and have the battery checked.

 

 

If it were mine I'd disconnect the battery from the bike's wiring, charge it (if possible), wait a few days and see if it goes dead on its own.

If ok after a wait (holds 12.6-7 V), connect it to the bike's wiring and see if it goes dead in the same time.

If so, then go looking for excess current draw from something on the bike. Pull fuses, test resting amperage draw, etc.

I had a new batt that would never take a charge...the Yuasa 1.5 A charger never went into float mode (13.2 V) from bulk charge voltage (~14.5 V), likely due to excess current flow. Bad batt...got new one under warranty.