I'm considering upgrading from a 12V to 24V trolling motor. Besides the motor, I know I'll need another 12V battery connected in series. Currently if have 2 batteries(1 cranking & electronics and 1 for the 12V trolling motor). I know I can connect another deep cycle batter in series to get the 24V. I have a 2bank on board charger. Finally, here are my questions.
1. Should the wires running from stern to the bow be able to handle the upgrade? Doesn't a 24V motor draw less current than the 12V motor?

2. How do I charge them when connected in series? Do I just take the + charger connector on battery 1 and the - charger connector on battery 2? Or do I need to upgrade to a 3 bank charger?

Thanks.

#1 really depends on size of wire you have now. Most boats that come with a 12v trolling motor the wire is too small. 24v will draw more on high speed settings = larger 50amp breaker. #2 The 2 bank should be able to charge both trolling batteries in series if it is a 12-24v charger. If it is a 12v 2 bank, you will have to disconnect one battery lead to charge both batteries. Then add a small 3amp 12v charger to charge the cranking battery. Do not connect the charger the way you described. It would be easyer for you to go to a 3 bank charger.

Thanks Gary. The good new is I have a 10A 12/24V charger. The trolling motor's wire looks pretty big, but I'll have to verify it is the proper gauge. What size does it need to be?

Anyone know how to fit 3 batteries in the battery compartment of an 06 or greater Lowe Stinger 175?

I'm bringing the trolling motor to Boris' tomorrow.When I add the 2nd battery, should I buy another battery like the one I already have or can I use another brand? It is only 1.5mths old.

i would try to match them same at least in specs size cca ect

Thanks RodneySr.
Boris Marine and Electronics upgraded my MotorGuide from 46# to 71#. It works great now. We can actually troll without having to use the outboard. Now I just have to get used to handling all that power with my foot.