Dinghy Power

[danapsy]

Just wondering if anyone has powered their inflatable dinghy with an electric trolling motor? What are the advantages/disadvantages compared to a small outboard? I had used oar power alone before, but we''re moving to a different mooring about 400 to 500 yards from the landing with some current present. Any suggestions would be appreciated.

[Sasha_V]

I use a riptide 58 to power our inflateable. Gets us on and off the mooring wonderfully.
A good AGM battery is pretty much a must. I created a "kit" which has the battery, an emergency little battery (small motorcycle). the inflator for the dinghy, a couple of patches and some glowsticks and things as one shoulder-strapped plastic box that fits under the seat of one dinghy and IS the seat of the other one)

The motor is a Riptide 48. It is not that much lighter then a 2hp outboard, but the weight is concentrated in the motor bulb, so it is easier to carry.

Its major advantage is that the car does not stink of fuel when we transport it, it does not leave that two-stroke flavour on everything and there is no smoke, virtually no noise and the ride is very sturdy (it does not just churn the water the way a small outboard seems to, the prop seems to be a much more efficient design and you can feel it pushing at every turn, so there is hardly a stern wake and no froth).

We have used it when it has gotten a little choppy and rough (20 knots) to get to and from the boat. it managed it with all of us on board....but I am not sure I would have been happy in anything rougher or if the boat was anchored in more open water.

We get really good life out of our battery-pack. About 1 and a bit hours on full throttle with the main AGM and then about 40minutes on half throttle with the little motorbike battery (we did a full test in water so we knew, before we got to FIND OUT the hard way). So basically it will get you into and out of trouble...sort of nicely.

Excellent for fishing, and I once attached it to the bow roller of the yacht for a joke. It actually moved us around quite smartly in calm water. Who knows, it may be a technique for parking in an incredibly conoluted and tight marina, sort of a detachaeble bow-thruster arrangement. (our boat is 26 feet and under three tons).

We plug the pack into the recharge outlet on our boat as soon as we are on board and it lives in its own little fiddled shelf (the outlet I built has two settings, a quick charge which takes form the battery bank and the motor running and a slow charge that just trickle feeds from the solar panel, so the thing stays plugged in till we need it).

I do recommend spending the extra money on the salt water rated motor rather then the freshwater trolling motors. The freshies work, but you are for ever trying rinse them and stuff and it gets kind of dull and pointless.


Sasha

[paulk]

Practical Sailor did a piece on using an electric trolling motor on a small whaler for ferrying to/from their main boat. I think it came out in the past few weeks.

[danapsy]

Thanks for the information and it was the article in Practical Sailor that started my curiosity about using a trolling motor. Sasha, did you simply convert an oversized plastic battery box for the storage box/carrying case, or did you use something else? Also, how do you connect it to your battery bank? I have a 12V outlet in my cockpit. Can it be recharged through that outlet without upgrading the wiring?

[Sasha_V]

Actually I built my own from scratch (it was raining, I was bored)...but now that you mention it, one of the small rectangular plastic boxes would do. Just sew a fabrix bag around it so that it has a comfortable shoulder strap and a pouch for the inflator.

Both the main battery and the little emergency battery have a dedicated ciagrette lighter socket. The trolling motor came with a lead that had two smallish battery clamps on it and I made an adaptor for use with a standard cigarette lighter fitting (the join spends most of its time duct taped up, but I wanted to leave the clamps in place for a "just in case" hypothetical situation that has never yet happened). So the deal is. Roll out the dinghy, plug in the inflator and make the little boat 3D. Unplug inflator, plug in trolling motor and vroooooom...well not so much "vroom" as bzzzzzz (very very quietly).

Actually, when we first got the motor we decided to test it on a local lake so that we would not get in trouble if it proved to be a piece of crap. It worked very well, and was so quiet that we accidentaly ran over a dozing swan on the lake. Swans do a really good job of acting agrieved and offended!

Yes, you can just recharge the battery by having a lead with a male cigarette lighter plug at both ends. PLug one end into your cockpit socket and the other into the battery-box socket and you will recharge to the same level as the battery bank (or actually you will get an average across all batteries). I personally would not want this box getting underfoot in the cockpit and being out in the wet more then it needs to be, but it is certainly doable.

As to upgrading your wiring. I have no idea what grade of existing wiring you have. IF the plug was installed with the idea of only ever running the GPS at the helm and they used appropriate wires, then likely it will not be enough. If they put the plug is so you could run a 12V spotlight from the cockpit, then it will definately be up to the job. Take a look under there. Chunky wiring is good. I am a big fan of chunky, low resistence, wiring. I think the difference it makes to boat weight is so minimal as to be insignificant in any application accept "maybe" up the mast.


cheers

Sasha

[sailnaway]

I think this may be note worthy the AMG batteries are water tight and will not short out if submerged. Also they may be put in any position but upside down.This is the information I got from West Marine when I bought thier batteries or should I say the brand they carry.I have one of two batterys on its side for about six months now seems fine.PS you have to have a charger for AMG type I have a Xantrex 20+