TOPIC:

So I'm going to upgrade my trolling motor from 12v to 24 volt. (Got a steal of a deal on a terrova) My 2 bank 12 volt charger won't cut it, so do I install a 3 bank 120v charger, or a 3 bank alternator charging system and just plug in a 12 volt charger into the system when parked?
If I put in a MK330pc at about $250, running my motor will not charge the trolling motor batteries. But with the boat sitting idle in the garage, it will charge and maintain the batteries.
If I put in a MK3DC, it will charge all three batteries with the motor running, and I can add a portable charger to the input circuit when parked.
3lbs vs 8lbs is not a big deal, but I don't want to buy both. losing my guest charger and isolator might give me enough room. I'm just looking for some options.

Mostly simple answer:

a) You likely wont run your outboard enough to do any significant charging. An alternator only puts out so much, and sharing that across all those batteries......well its probably not going to do much.
b) You will likely have it at home enough to do very significant charging.

Keep it simple, use an AC outlet to do your charging for the trolling motor batteries.....with a 3 bank to do them all.

Also if you have the space for batteries, go get 31 series Duracell AGM from Sams Club (or elsewhere). They have a great reserve and a good price. I had nothing but great success with them. I put them in my stratos when I had it, for the starting and the 3 (36v) terrova batteries. Now I put 4 in the big boat. So worth it in my opinion. Since they last longer, they dont discharge as much, thus increasing their overall life. So all in all, you get longer run time, longer life span, and the additional costs probably boils down to $5 or $10 a year at most over the lifespan.

This is the specific battery I am talking about. Just take a look at the dimensions of the battery (its a bit bigger) and make sure you have room.
www.samsclub.com/sams/duracell-agm-deep-...tmagm/prod3590232.ip

Thanks for the input. I didn't think about a different battry size, now I gotta find out who ran off with my tape measure!

I have a two bank charger for my trolling motor onboard. I generally don't run my starter battery down but if I happen to, I pull start the kicker and let it charge the battery enough to get me going again. I do generally put an external battery charger on the starter battery if I am doing several days of fishing with the trolling motor and not much running of the engines to charge the starter. I have only run my starter batttery down one time that I can recall - twice at the most. My boat comes home every night or is docked with AC in it when we are renting a place so never an issue.