I'm an authorized re-seller of Vaperz Cloud. We go through a lot of HOG's. First and foremost. I'm guessing you got this used, since I would assume you would contact the shop first, if you bought it new. Vaperz Cloud is a FANTASTIC company! I can't sing their praises enough. I would send them an email with pictures if you are worried/wondering. Include better pics to show the full battery "sled" so the engravings for + - are visible and take a pic of your battery door too. They are very responsive to telephone as well. I would imagine they will help you out. I also would check the authorized re-seller page if you did get it at a shop. I'm guessing not everyone is up, but it's definitely a place to start, if you did purchase it new.
I don't want to speculate as I did not sell the device. I hope that leads you in the right direction. You can message them on Facebook as well. Basically. Go to the company. If you can't trust the seller, wether shop, site, or used... go the manufacturer. They are a U.S. company in Virginia, so you can actually contact them. That's my advice, and I wish you the best of luck! HOG's are fucking AWESOME!