I'll just use these
http://www.ebay.com.au/itm/2x-Holder-Case-AA-D-Cell-Battery-Adaptor-Converter-/290610668711?pt=LH_DefaultDomain_15&hash=item43a9bee4a7
Another thread kicked off on this subject.
https://budgetlightforum.com/t/-/8299#comment-164220