12V Propulsion in a 15"

[Sailinbob]

Hey All first post,

I'm in the buying process for a 15" Precision as my first sailboat with the intention of going bigger as my skills improve. Based on where I plan on launching from I will need a motor of somesort to get out into open bay. I was looking at 12V Trollers as a cost effective option, however when looking at the addition parts needed things began to get expensive and I started asking myself install questions. I'd prefer to mount the battery in the foredeck hatch but that brings up 2 more questions.

1) how to mount the battery- I'm thinking battery box/power meter and 1-2 accessory circuits for a FM/VHF radio at a later date - still doing homework to see it that's feasible. - my thinking was to keep the cockpit as clear as possible, and the batter and motor would better balance the boat

2) how to run the wires aft. Having not seen or been on this type of boat I'm not sure. Ideally the cockpit seats would be accessible from the foredeck and i could just run the troller power wires aft.

Thanks for the help

 

[saildan]

Re: 12V Propulsion in a 15"

I'm in the buying process for a 15" Precision

I do hope your meant to say 15 foot.

I was looking at 12V Trollers as a cost effective option, when looking at the additional parts needed things began to get expensive.

Were you expecting to just pop in a couple of AAs?

Motor, cable & connectors, Deep Cycle battery, battery charger for a Deep Cycle battery.

Them's the basics.


One way to keep costs (and weight) down is not to overbuy on the battery. The battery amp hours (AH) should = your usage needs plus about 20%.

Say your motor draws 30AH and you want to run it for 4 hours between charges, tops.

30AH X 4 hours running time = 120AH need.

120AH + 24AH (20%) = 144AH battery is what you'll want to have.

I'd prefer to mount the battery in the foredeck hatch but that brings up 2 more questions.

1) how to mount the battery- I'm thinking battery box/power meter and 1-2 accessory circuits for a FM/VHF radio at a later date - still doing homework to see it that's feasible. - my thinking was to keep the cockpit as clear as possible, and the batter and motor would better balance the boat

2) how to run the wires aft. Having not seen or been on this type of boat I'm not sure. Ideally the cockpit seats would be accessible from the foredeck and i could just run the troller power wires aft.

The foredeck compartment isn't a bad idea, being an open dinghy everything needs to be secure.

There is the consideration of cable length. Above a certain length resistance in the wire saps power so you start at one end with 12v and end up at the other with 10v. To compensate longer wires need to be a larger gauge.

There probably isn't a straight shot from the compartment to the stern. The seats often have safety flotation of some kind filling the cavity. You might need to bore a tunnel through 8' of plastic foam.

You could make a lazzerette storage compartment in one of the seats to keep cable length within the motor producer's recommendations.

Ask Precision Boats what the layout is.

 

[steelespike]

Re: 12V Propulsion in a 15"

There are motors with self contained batteries eliminating battery placement etc.
Surely more expensive and range may be limited. But a good look into solution.

 

[tschmidty]

Re: 12V Propulsion in a 15"

It'll work fin. You say going into a bay though, what kind of current might you have to contend with? You'll only get maybe 3 MPH out of a 30# trolling motor, and a lot of tides can put out 5-6 mph currents. So keep that in mind. You won't need to go crazy on the battery, and if you need to mount it up front you will need thicker cables. No good idea on how to run said cables on your boat, you'll just have to poke around.

 

[saildan]

Re: 12V Propulsion in a 15"

There are motors with self contained batteries eliminating battery placement etc.
Surely more expensive and range may be limited. But a good look into solution.

http://www.electricpaddle.com