Looks very similar to the Battery Tender Junior, which I have used before. I think it will work fine.
Also, with the battery at 50% charged, you could have just thrown it in the bike and gone for an extended ride.
That's the great thing about LiFo batteries (lithium in general). They provide the same amps until right before they completely drain. So your 50% charged battery would start your bike just as well as a 100% charged battery.
Doesn't hurt it one bit, either, to sit at 50% voltage for even a few months.
2009 Aprilia Tuono - Ginger
2001 XR650R BRP (Big Red Pig)
2006 Honda 599 - Ex wrecked it :-D
2007 Honda CB900F (sold)
2006 Honda VTX 1300C (sold)