Have seen this question asked several times on how or can I get 12 volts from my 24 volt set up safely. Was watching a YouTube video this morning and saw this almost foolproof setup. Gets you your 24 for trolling motor and then a couple of leads for separate 12 volt hookups from same system. Looks like thy offer sever different configurations. And may be able to find a little cheaper. In the video he did reference Cabelas.
24 Volt Series Trolling Motor Connection Kit with On-Board Charging (RCE24VBCHK) | Connect-Ease. Connect all your marine equipment with ease.