Adriano da Cunha has re-released a small utility he created some years ago to load 16k/32k ROMs into SRAM (or RAM) cartridges. SRAMLOAD has a number of features, allowing you to load ROMs at adresses 0000, 4000, 8000 or C000 and verfifying that they were written correctly. You can find SRAMLOAD in the utilities section of Ardriano's webpage.
Relevant link: SRAMLOAD 1.0