24V/82 lb TM on 20’ Champion, been running it for many, many years and no issues

Does either of y’all’s calculations assume “ohms law”? As voltage drops, amps must increase to maintain watts (power). As the voltage of the battery starts to drop, the amperage requirements rise to do the same amount of work.

You can’t just divide a battery’s load into its total capacity to get a time. It would vary as the battery is depleted.

I run a ghost on 24v on my Triton TR186DC. It’s a heavy 18.5 footer and I rarely go over 4 or 5 on my speed setting. Most of the time I’m using speed 3 to 4. On 7 or above it’ll throw you out of the boat if you aren’t paying attention and it’ll zip you across a cove pretty quickly. I have 2 x Amped 80ah lithium trollers and can fish a 2 day tournament and have like 40% left. If you go 36v you can get away with less ah batteries, say 50 or 60. If you go 24 then I’d say minimum 60ah and would suggest to step up to 80 or even 100ah. If my lithiums are fully charged, I see over 27v at the trolling motor plug.

Thanks Steve. Are you running an old Motorguide?

I have never heard a man say “I wish I had less power”! Just sayn……. https://youtu.be/4d978M3mZSk?si=kmxgwDePhYPWMbnC

Thanks bell0347, that's great info because I'm considering going lithium when the time comes. Times have changed and now batteries, especially lithiums and even AGM's are a big expense. On my 36v Ghost, like you most of the time I'm fishing on speed 3 to 4. I've never gone past 6 and I don't even know how high the numbers go to. I fish a lot, but I don't fish tournaments and most of my trips are now 6-8 hours, 9 to 10 would be rare. I've never ran out of juice or ever noticed my TM being sluggish with how I fish. I have 3 Duracell AGM's group 27 now and they have lasted 4 years, but on another thread here, guys are saying they have gotten 5 to 6 years of use. Once I saw I had 4 years, I thought they are going to fail sometime soon, so that's what got me looking into it now. I saw a good deal on (3) 50ah's, but with Christmas and my boat insurance is due now, timing is not great. Plus the older I get (63), decisions are harder to make. Getting wiser doesn't seem to be working! Maybe it doesn't have to do with age or wisdom, when you are flush with cash decisions are a lot easier. Thanks again.

I got the new GARMIN trolling motor on my Cougar and the guy that put it on forgot to put the jumper on it so I ran it over a year on 12v and I fish a lot! Fished Basschamps and several other tournament until I finally realized what was going on. Had Rockwall Marine check and they said it was missing so now I’m good. But honestly cant really tell the difference LOL.. These new TM’s just dont draw power like the old ones.