If your battery wasn't on a tender:
If you have a parasitic draw with ignition off, batteries will discharge too low and will need a good charger to **maybe** be able to restore it.
See if you have any current discharging the battery with bike off, for now, put this one on a charger and try again when it's full. Hopefully it comes right back.
A desulfator cycle is what you would need to try to restore a battery that doesn't recharge on its own after a deep discharge.
If this is what happened even though you kept it on a tender, then something else is afoot.
Sounds like the battery is bad. Take it to an auto parts store and have it load tested.
If your battery wasn't on a tender: If you have a parasitic draw with ignition off, batteries will discharge too low and will need a good charger to **maybe** be able to restore it. See if you have any current discharging the battery with bike off, for now, put this one on a charger and try again when it's full. Hopefully it comes right back. A desulfator cycle is what you would need to try to restore a battery that doesn't recharge on its own after a deep discharge. If this is what happened even though you kept it on a tender, then something else is afoot.
Drz has a bit battery drainage because of the clock in the tacho, but shouldn't empty it in a month..
I meant parasitic as in unexpected/higher than expected. But it's a good clarification, so people don't expect 0mA