I haven't changed one in the 4915, but it is probably similar to a 4615 in which case it uses an internal rechargeable battery. It is a delicate procedure as the power cannot be interrupted while the battery is replaced or you will lose all programming. It is soldered into the main circuit board so a good knowledge of electronics is required. If you don't feel confident, take it to a dealer.
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Anyone need a manual for a Samsung ER-4900, ER-4915, or ER-4940? Go here:
http://the-checkout-tech.com/manuals/cashregisters/samsung1.php
Mark, June 2010
