Battery powered boat trailer w

[Don Fry]

I’ve got a boat, a 6 meter or so, fast 4 berth daysailer.  Now I’m not taking it to sea again, too much of a handful, and beloved is too fragile to haul dagger boards up and down, work jibs.  All too stressful and dangerous.

It’s on a trailer, and it floats in 20 cm of water with the dagger boards up, so it makes for a nice thing to explore rivers in, the canals, lakes. I’ve had it for 20 years, and as well as a lot of sea time, I’ve explored a lot of inland France, living onboard for anything up to 6 weeks at a time.

It a heavy thing, trailer, hull, equipment, wine and whiskey, about 1500 kilos. And the manual winch on the trailer is now too getting too heavy for me to recover it on a slip.

So get an electric winch thinks I. I’ve identified a likely candidate, 12 volt nominal, 750 watt motor, rated pulling capacity 3000 kilos. Controlled by wired in, or wireless remote control. 

I don’t want to mess with cables. Any reason I can’t use for an example, a 4s 10000 mah, 30c Life battery. I mention Life, because it’s full charge voltage 14.8 volts is similar to a cars running motor delivery voltage of 14.4 volts. 
It strikes me it’s not a big load for such a battery, it will only need 2 minutes to haul the boat on, and I can recharge it off the car when needed. And I get a self contained winch.

Any thoughts?

[Chris Bott - Moderator]

4S LiFeP04 sounds ideal for this application, Don. 

I've used 4S A123 flight packs to start small cars with flat batteries. Voltages are spot on. 

 

How about something like this, there are plenty of different makes/sizes show up from a quick web search. Self contained in a nice case and designed to be charged from a car battery charger etc. 

 

This is just a random example:-

https://www.tayna.co.uk/jump-packs/noco/noco-gb20/

[Don Fry]

Thanks Chris, that’s reassuring. I have a vision of leaving the manual winch in position, but installing a traveler pulley alongside it. The winch wound then be attached to the cars towbar, at the top of the slip, on a bipod.

Haul them boat on to the trailer, wire going over the traveller to keep the pull in the right angle. Then hold the boat on the trailer with the existing winch, and use the power winch to haul boat and trailer up the slip, avoiding stressing the car, or me. Or leaving an expensive winch on the trailer. 

I will have a think about the starter unit. My plan was no more than put a Life in a box, on the winch, as a self contained unit, standard aircraft plugs, XT 90 whatever, and do the charging with a standard balance charger. The fag lighter socket in the boot of the car is good for 80 watts continuous I think, but check and charge at the rated spec.