Try contacting the person who sells them. I have read he is very good with correcting any problems and he may be able to help you.
Right before I purchased mine I contacted him about wanting a longer wire for the battery as I had read a few owner's say several inches longer would be be easier to work with. He said he could do what ever I wanted but he had heard of no complaints. Decided to go with what he had but haven't installed it yet.