This is link to a Renogy charge controller sold on eBay: positive ground charge controller it has positive ground! If you used it and negative grounded loads you will have a problem. When you buy on eBay, don't assume anything...
The safest thing to do is to NOT buy it, unless you know or can make your house system safe for use with it.
The safest thing to do is to NOT buy it, unless you know or can make your house system safe for use with it.