DB1/SL is an abbreviated combination of Declining-Balance 1 and Straight-Line.
The Calculate Depreciation batch job calculates a straight-line amount and a declining balance amount, but only the greater of the two amounts is transferred to the journal.
The program can handle declining-balance calculation using various percentages.
If you use this method, you must enter the estimated useful lifetime and a declining balance percentage in the FA Depreciation Books window.
Setting Up FA Depreciation Books Manually
Fixed Assets Depreciation Methods
Fixed Asset Depreciation Setup