Electric motor tender, charging on board

[kingfisher]

Hmmm, this summer we plan a trip to the Channel Islands. We usually sail in Holland, so never need a tende. I'm thinking of buying an old second hand one, and powering it with an electrical outboard, they seem to go for 200 euro's. But how does one charge one onboard? How do I temporarely connect it to the boats electrical system. All I have is a 12V plug. Do I just plug it in, straight from the battry to the 12V socket. That seems a bit too easy.

 

[RAI]

No idea, but if its a standard lead acid battery, then connecting it to the ship's battery bank and running a charger or alternator will charge it too.

However, why not buy an old 2-stroke outboard to go with the old tender?

 

[sailorman]

ihmo dont buy electric
get a 2 > 3hp 2 stroke you will have more power & know how much fuel you have left in the 5ltr container you will always have with you in the dinghy
tidal waters & electric outboards a no no TM2W

 

[Moonshiners]

connecting the battery of the outboard to a 12v socket won't charge it. you would need to install some kind of inline 12v charger or run something off your altenator like a split charging system. Someone will be along with chapter and verse shortly...

I'm with Sailorman, I'd go for a small hp 2 stroke thats not too old.

 

[pvb]

[ QUOTE ]
I'm thinking of .... powering it with an electrical outboard, they seem to go for 200 euro's.

[/ QUOTE ]A 200 euro electric outboard won't be any use in tidal waters. Simply not powerful enough.

 

[sailorman]

ok 4 fishing in a Lake /forums/images/graemlins/grin.gif

 

[kingfisher]

Ah, but SWMBO and I hate people who break up the silence of the perfect sunset by letting their offspring run wil on the tender. They are up there with jetski's. So I don't want to join them. We've got a seven year old who is going to turn into a teenage monster at some point (that's what I'm trying to tell his mother, anyway). So a nice, quiet electrical engine would be perfect.
The idea of my family and I being swept out to sea does hold some value though. hmmm

Second hand tenders are waaay too expensive on this side of the Channel (nobody uses one, so supply is low).

 

[sailorman]

Dont forget when you & your family get swept away on the tide
" [--word removed--] Ole Sailorman Was Right" /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif

 

[VicS]

If you really insist on an electric outboard take a look at the Torqeedo range

However take note that the equivalent petrol engines they claim them to be equivalent to are much more powerful than the actual propulsive powers that these things produce. They are capable of high static thrusts which are the figures used to seduce everyone.

They are just touch on the expensive side too.

Some use a separate 12 volt battery that you could charge alongside your boat batteries although not from them, but the higher power ones use higher voltage batteries.

 

[DaveS]

I use a small, cheapish, electric outboard (when justified - last year I just rowed everywhere). Issues to think about are connecting the battery for charging, connecting it to the outboard while in the dinghy, and making sure that sea water keeps out of the electrics. The solution I came up with is as follows.

The battery lives permanently in a plastic battery box, with short leads from the terminals to a 2 pole polarity keyed socket which hangs just below one of the box lid cable exits, i.e. about 200 mm above whatever the box is sitting on. The box is kept closed by a semi-permanent strap which also incorporates a lifting eye.

On board, the box is placed in a cockpit locker and held in position by a click fitting strap. A matching 2 pole plug connects it to the main domestic battery via a circuit breaker at each end of the wiring run; as well as protecting the cable, these allow a choice of whether or not to parallel the batteries, e.g. waiting until the engine is running and / or the charging current to the main battery has started to fall off. Once both batteries are charged they are left connected, effectively giving a bigger domestic bank.

For the dinghy, the battery is lowered from a davit using a three part tackle with a carabiner in the lifting eye. The outboard cable also terminates in a 2 pole plug which is then plugged into the battery socket. Ready to go!

After use, when the outboard cable is wrapped up again, the plug fits into a "dummy" socket attached to the unit to protect the pins and keep the coil neat. Needless to say, all brass connectors are well vasalined.