The other day I saw what I took for a generator system that looked
like a trolling motor. I see that Ampair makes a couple of boat towed
water turbine units but they don't look like the unit I saw. I'm
curious as to what my trolling motor would generate if towed and
whether it could be used in a charge-pump circuit to do battery charge
duty. Anyone have any experience with towed generators?

We have a tow generator on our boat. When we went from VA to Portugal,
It generated 6-7 Amp per hour/ About 167 amp/day. It was a Ferris tow
generator.


Hanz


DaveC wrote:
The other day I saw what I took for a generator system that looked
like a trolling motor. I see that Ampair makes a couple of boat towed
water turbine units but they don't look like the unit I saw. I'm
curious as to what my trolling motor would generate if towed and
whether it could be used in a charge-pump circuit to do battery charge
duty. Anyone have any experience with towed generators?

Amps per day is not an interesting unit.

It doesn't include any indication of the voltage.
It doesn't include any indication of how long the power
was provided.
It's a rate of change, not "how much".

Watts is more interesting.

"Hanz" wrote in message ...
We have a tow generator on our boat. When we went from VA to Portugal, It generated 6-7 Amp per hour/ About 167 amp/day. It was a
Ferris tow generator.


Hanz


DaveC wrote:
The other day I saw what I took for a generator system that looked
like a trolling motor. I see that Ampair makes a couple of boat towed
water turbine units but they don't look like the unit I saw. I'm
curious as to what my trolling motor would generate if towed and
whether it could be used in a charge-pump circuit to do battery charge
duty. Anyone have any experience with towed generators?

Since the boat is moving 24 hours per day, then .....

Amps per day IS AN INTERESTING UNIT. HOW MUCH power does you boat using
in a 24 per period????

Hanz


Chuck Tribolet wrote:
Amps per day is not an interesting unit.

It doesn't include any indication of the voltage.
It doesn't include any indication of how long the power
was provided.
It's a rate of change, not "how much".

Watts is more interesting.

"Hanz" wrote in message ...

We have a tow generator on our boat. When we went from VA to Portugal, It generated 6-7 Amp per hour/ About 167 amp/day. It was a
Ferris tow generator.


Hanz


DaveC wrote:

The other day I saw what I took for a generator system that looked
like a trolling motor. I see that Ampair makes a couple of boat towed
water turbine units but they don't look like the unit I saw. I'm
curious as to what my trolling motor would generate if towed and
whether it could be used in a charge-pump circuit to do battery charge
duty. Anyone have any experience with towed generators?

Amps per day is a nonsense and meanigless unit and indicates a
complete misunderstanding of the principles involved.

Amps may be helpful when looking at an instantaneous situation. A
constant 5 amps into 13.8 volts would be enought to run the nav
instruments , radio and some of the load required for a fridge or
autopilot. A seemingly 'free' source of energy but to get the 69 watts
( 5 * 13.8 ) the system ie propellor, gearing , alternator, charger is
unlikely to be anything more than 20% efficient so around 350 watts
are exerted as drag on the boat, about 3/4hp. A worthwhile sacrifice I
would say.

To make sense you need to convert to amp/hours or watt hours.

"nimbusgb" wrote in message
oups.com...
Amps per day is a nonsense and meanigless unit and indicates a
complete misunderstanding of the principles involved.

Indeed.

To make sense you need to convert to amp/hours or watt hours.

Now you're making the same mistake: amps per day or amp/hours.... It is amps
* hours.

Meindert

nimbusgb wrote in news:1181027399.917094.159070
@m36g2000hse.googlegroups.com:

Amps may be helpful when looking at an instantaneous situation. A
constant 5 amps into 13.8 volts would be enought to run the nav
instruments , radio and some of the load required for a fridge or
autopilot.

"Lionheart", an Amel Sharki 41 ketch, has a "shaft alternator" on her
freewheeling shaft. You must have a hydraulic transmission designed to
be free wheeled to use one, not just "leave it in neutral". The Perkins
transmission on the 4-108 is larger than most of them.

Her shaft turns, at 6 knots through the water, about 70-80 RPM. This
turns a big pulley made for a flat cogged belt. The pulley is about 12"
in diameter up near the back of the transmission. The belt drives a
special, slow-turning alternator, who, I'm guessing, is turning about 300
RPM at this speed. It's driving a 2KW Raymarine radar/color chart
plotter, Garmin 185 GPS/sonar, a string of B&G Network instruments,
including B&G Network Pilot electro-hydraulic autopilot, a Yeoman chart
table, a Dell Latitude w/HP Printer, a 12V fridge, bilge pump, water
pump, all the lights. Loaded down, the shaft speed drops, of course, but
she'll put out 15-18A at 14.2-14.4V to charge the 660AH golf cart beasts,
too.

As the Amel is already slower than dirt, a sturdy but leisurely cruiser,
I don't see any difference between on and off positions on the control
panel for the shaft alternator. Just pulling the 200 gallon water
tank....er, ah....6' fat keel...that's better...is draggin' her down to
make her comfortable. Noone is in a hurry on a Sharki...(c;

Larry
--
If electricity comes from electrons, does morality come from morons?