this little $20 module should supply a 24v from your 12v battery if you mostly slow troll.
it can give you 15- 20 amps and no need for a second battery.
Specs list 20Amps max and with 15Amps add cooling fan which will draw power
【Output Power】Input voltage * 20A, such as: input 12V * 20A = 240W, input 24V * 20A = 480W，input 60V * 20A = 1200W Note: Do not use the short-circuit output method to adjust the current. It is recommended to use a smaller adjustment range.
So 480 watts won't give you mach and note that is max, so running at that it probably won't last long
15-20a? I got a small watersnake and that draws 45a max . What happens if you give it a bit much wellie ? , fry the unit and leave you to row home ?
Just an observation but the 12v motors seem to go about 1 lb thrust per amp draw . Most electric outboards here are rated in lb's of thrust ....which tells you nothing ....like whats that in hp so I can get a rough idea of size req , and how much current so one can size cables and batteries.
I just sussed it as a lb per amp after looking at various specs from different manufacturers and saw a bit of a pattern .
just a suggestion gents... a slow troll means low amps maybe 10 ampsx24v . I am not suggesting max power on a 24v kicker ! ..150khz should not create any audible noise power wise. Us old boaters probabaly don't hear much above 12 khz Young ears can catch 18-20KHZ violins . Most phone services only carry the 300-3200 hz band of speech.
again..just a suggestion gents...if anyone wishes to try it. btw that unit is the same as used to build a pulser circuit to clean injectors like ETECs needing 50-55 vdc)
Far out , should be able to ski behind that 