Advice adding the credit card service fee to invoices

I own a mobile RV repair and maintenance company and have been absorbing the CC fee as part of doing business.  At the end of the year, it's a big pill to swallow when you collect all the information for tax purposes and see this figure.  Some of my distributors are now charging 3+% when I order parts and supplies.  For those of you who currently charge a CC convenience fee, have you had any negative feedback from your clients?