Hi everyone! I'm new to all this,and know very little about bike mechanics but hope someone somewhere can help with my problem. In 2015 when my wife got home from deployment, she decided to go out and buy a NEW 883 sportster. Since then it's been parked and covered in the garage for 2 years unridden. (I wasn't allowed to ride her baby!) now apparently it's my bike, so I got it out last weekend and it wouldn't start. I knew the battery was toast so bought a new one. The new one was faulty. Said it was charged fully but died with a load on it. Sent it back and got a replacement. Had it tested and all looks good. But when I connect it to the bike there's nothing. Apart from red security light. And lights only light up if I put an outside power scource to the battery. Is there something that could be draining it? And if so, is it something I can look for and try fix? Thanks in advance