Ok I bought one D31M for my cranking battery and three D34M for my trolling motor batteries, I just now looked at my boat that I am selling and I have all four D31M batteries in it, do I need to exchange the trolling motor batteries for D27 or D31's ? The new boat is quite a bit lighter and supposedly the new trolling motor is supposed to be more efficient, never the less I do not want to run out of juice, opinions ?

What's wrong with the 31's? I'd leave em

Nothing but I mistakenly bought three D34M's for the new boat, they do not have as much runtime as The 31 or 27's, from the research I have done I guess they will be ok, especially if the Ghost trolling motor does what they say it will do.

I ran 34s on my trolling motor for 1 trip because it was all they had in stock the night before the tournament and by the end of the tournament we were running the trolling motor on 10 power just to get around. It was crazy windy that day, but I have never before had that issue with cheaper batteries. I went to 31s the next week and haven't had any issues but I still feel like I am not getting as much out of the trolling power as I used to. I typically ran my ultrex on a 4 but am finding myself at 5 more often now. Batteries still last all day though.

Optimas have really poor reserve capacity. They would be my last choice for trolling motor batteries.

I have had four yellow top Optima batteries in my boat for over 8 yrs now...they have never quit on my trolling motor and have never failed to start the big motor...don't know how much reserve they have but they never have failed me even with the new Ultrex..

Gotcha....yeah I'd go with 31's. I like the Duracell 31 AGM from Sam's club. $179

Been running them for as long as I can remember, never once have I ran out of battery, I just did not order the 31's by mistake, may take the 34's back.

You could always be the guinea pig for the new Ghost and let us know...

I have one ordered, will report back if i ever receive it.

Depending on the age of the batteries in your OLD boat I would opt for the larger size into the new boat. Makes no sense to send something down the road with better batteries than you have now.

If you just bought the d34 Id try and return them.

I think this is what I will do, don't want to take the other batteries out of old boat, my son would probably frown.

yes I wouldnt short change your son, now selling on craiglist etc, I would put new walmart batteries in there and call it good.