Boat battery & charger ??

[fordtruckin]

I’ve got a 16’ lund tinner that I’m hoping to upgrade the outboard on this summer. Provided I go with an electric start, would one battery be enough to run the outboard, a 45# trolling motor and a Helix5/7? I’d prefer not to weight down the boat with multiple batteries but if needed that is an option. Would it be worth trying for one season and then reevaluating? I’ve been looking at a Minnkota charger as well and was planning on getting a 1 bank charger but now am contemplating a 2 bank just in case. I prefer to keep things simple so there’s the possibility I’ll get an outboard with a manual start as well. Those light weight lithium batteries aren’t an option for me either.

[Tannerdog]

Not sure what HP you are planning but if the motor has electric start AND a pull cord to start you should be good. If electric start is the only option, a second, isolated batter for starting is a very good idea. Could always bring along a portable booster too for emergency with one battery. Fish finders don't use much power but electric motors can drain a battery pretty quick.

[WV911]

I always had separate batteries for the motor and trolling motor.

The normal battery powered the starter and accessories (fish finder) and deep cycle batteries for the trolling motor. My trolling motor was 24V so needed 2 batteries but same theory for 12V with 1 battery.

Normal starter batteries aren't designed to be constantly drained and recharged and I don't know if deep cycles are good as a starter battery, you would have to check the required CCA.

Costco Kirkland batteries are good for the money, I never had any trouble and they are well priced.

[jungleboy]

I run an electric start 25 Yamaha on my tinner and I have been using a small utility atv battery for the last few years without incident. When you think about it the small batteries they use on an Atv runs everything.
Also a small lithium 12v battery for the fish finder.

What I am getting at is you can run small batteries that are light weight as a starter for the outboard with a larger battery for the electric trolling motor.. you get the Use of the trolling motor this way without worrying if you will have enough to start the main engine when the time comes.

[elkhunter11]

If you plan on using the trolling motor a lot, then go with a separate battery for the trolling motor. And go with a deep cycle for the trolling motor, and a starting battery for the engine and Helix. Deep cycles don't make good cranking batteries, and regular cranking motors don't like the voltage being drawn down. If you don't use the trolling motor a lot, and you really want to try one battery, go with a good quality dual purpose group 31 marine battery.

[eyeflyer]

I would definitely run two batteries. A marine starting battery for starting and sonar maybe and a marine deep cycle (series 29 or 31) for the trolling motor. Go with the two bank charger if you ever go to a 24V trolling motor you will be glad you did. If you do a lot of trolling I would also suggest upgrading to a bowmount, at least 55lb. with a 54" shaft. The control is much better on a bowmount than a transom mount unless you are going to backtroll all the time.