T-Pain Is On A Boat: [Electric Boats] Torqeedo and battery monitoring

Thursday, October 24, 2013

[Electric Boats] Torqeedo and battery monitoring

Robert,

I saw your question about the Torqeedo and battery status. The GPS works fine as far as speed goes. I've compared it to a handheld gps, and my girlfriend's phone, and they all agree.

Obviously, however, I must be doing something wrong on the battery monitoring - I've NEVER been able to get that to work. Which is probably fine, since my batteries have been really flakey anyway.

I'd be curious to know of other Torqeedo owners have had better luck with that feature.

John

From: Robert Lemke <robert-lemke@att.net>
To: "electricboats@yahoogroups.com" <electricboats@yahoogroups.com>
Sent: Thursday, October 24, 2013 8:11 PM
Subject: Re: [Electric Boats] monohull performance

Ned,

Wow, your really into electric boat endurance racing. My hat is off to you. About 15 years ago I was racing my electric scooter against the gasser scooters. Ran an Etek at 48 volts with (4) Odyssey PC 680 AGM batteries and a 400 amp controller and romped them good. The last time I raced this group, instead of the 3 mile course they held it on Route 66 in Arizona for a 50 mile run. The AGM's only had a 6 mile range so ended up towing a 490 lb battery trailer.

Thanks for the tweaker info on the Torqeedo accepting up to 65 volts, how does the fancy GPS computer calculate your range running at that voltage?

Bob

From: Ned Farinholt <nedfarinholt@comcast.net>
To: electricboats@yahoogroups.com
Sent: Thursday, October 24, 2013 5:07 PM
Subject: Re: [Electric Boats] monohull performance

Bob,

Last year I ran the same hull with one Cruise 4 and one 18 cell 160ah bank. It hit 15.5 mph WOT, almost 5 kw. There is definite room for improvement on my part with prop tilt, depth, and some aeration suppression. Todd Sims has hit 18 mph with twins on a light hull and not much battery weight. I am single minded about winning the Wye Marathon so I need enough battery for 25 miles.

If I took out the 160 ah bank and had only the weight of the 100ah bank, saving 100 lbs, I am pretty sure I could hit 16-17 mph single and close to 20mph twin.

The Cruise 4 is limited at 65volts or I would have gone higher in voltage. What I do now is to charge to 68 volts and burn off with a tea kettle for a few minutes to get under 65 volts. Of course, she soon drops to 57v for the bulk of the race. I am thinking about running 20 cells with a tap switch to adjust the voltage as she drops to 3.2 per cell.

Torqeedo has done a great job engineering their motors and props and Todd Sims at http://www.epowermarine.com has been a great help to me in tuning my boat.

My main reason for running twins is that my boat loads the single to such an extent that in warm water the motor cuts back in power to protect itself thermally. With the twins, this does not happen or certainly to a lesser extent.

Ned

On Oct 24, 2013, at 4:31 PM, Robert Lemke wrote:

Ned,

Thanks for sharing your specs. Have you run the test on one Cruise 4.0? The reason I ask is I'm thinking with the numbers you produced with (2) 4.0's there might have been some interaction between the props. I also use LiFePO4 cells and for a 48 volt motor I use (16) cells in series for 51.2 volts. Your (18) cells produces 57.6 volts so about 11% more rpm. The V30 prop with no slip would have a speed of 30 kmph (18.3 mph) at standard voltage or 20.3 mph at your voltage. Slip with these numbers is 21% which is low for a conventional high revving prop for a gasoline outboard but IMHO a bit high for the purpose designed Torqeedo prop. I could be out in left field on this not knowing the drag of your hull, but Torqeedo prides themselves on their 1300 rpm prop design.

Bob

From: Ned Farinholt <nedfarinholt@comcast.net>
To: electricboats@yahoogroups.com
Sent: Thursday, October 24, 2013 12:40 PM
Subject: [Electric Boats] monohull performance

Tom,
Thanks for sharing the performance information on your electric launch.
Here is an update on my runabout now that I have added a second motor and battery bank. These runs were made on a nearby lake.

overall length : 19 ft; beam 54 in.
water line length: 18 ft
total weight including one pilot is about 900-1000 lbs; 300 hull, 100 motors, 350 batteries, 150 pilot, 15 charger, 10 LA 12v, etc
motors are Twin Torqeedo Cruise 4R
props: Torqeedo high pitch
water: 69 deg F fresh water
wind less than 5 mph
water surface smooth
batteries: 18 cell 160 ah LiFePO4 plus 18 cells 100 ah LiFePO4 for a total of about 15kwh.

Combined power to both engines kw--mph (average of two way runs)

0.6kw--5.1mph
1.0--6.1
2.0--7.8
3.0--9.5
4.0--11.0
5.0--12.5
6.0--13.8
7.0--15.0
8.0--16.0

Adding another crew of 150 - 200 lbs reduces the speed on plane by about 1mph.

I ran this boat in the 24 mile Wye Island Electric Boat Marathon but hit a submerged object near the beginning of the race and came in third with one engine and carrying another passenger. Photos of the race participants can be seen at http://jpbliss.smugmug.com/Boats/Wye-River-Electric-Boat-2013/32366923_v5hNPr#!i=2817852500&k=WhCXZpN

To compare to yours and Steve's data, mine should run at 6 knots for about 6 hours or at 5 knots for 12 hours using 12kwh of battery.

Ned

On Oct 24, 2013, at 10:51 AM, <boat_works@yahoo.com> wrote:

Hi Steve,
Running a 20' monohull "all day" at six knots using four FLA GC batteries (probably 220Ah max) is astonishing.

You have perhaps 5kWh of energy on board, and pushing a boat like this to that speed could easily take 2.5kW, meaning that if you ran the bank down to full discharge, you'd be likely to have a bit more than two hours run time. Actually, less, since the Peukert Effect hasn't been factored in.

Do you have "Watts per knot" data to share? I'd be particularly interested to know power consumption at 4, 5, and 6 knots. You can see the performance of my launch at: http://www.grapeviewpointboatworks.com/chart.html

-Tom

---In electricboats@yahoogroups.com, <electricboats@yahoogroups.com> wrote:

I have a Duffy 20 named Sparky, posted pics in folder named "Sparky". Ours is unique in that its an outboard drive unit. I use the Torqueedo 2.0 cruise. Boat is unbelievably quiet, we operate on 4 6v deep cycle batteries from Costco. We can cruise all day at 6 knots. I'm charging with solar at home might mount the panels on the boat but looking at flexible panels now available on ebay. We'd mount them to the roof. Boat is stored on trailer near home so I use external panels from garage roof. Duffy's are the original electric boat ours was built in the 70's.

Steve

---In electricboats@yahoogroups.com, <matwete@...> wrote:

Sent to the moderator...

-----Original Message-----
From: electricboats-owner@yahoogroups.com
[mailto:electricboats-owner@yahoogroups.com] On Behalf Of Dag Hanssen
Sent: Tuesday, September 24, 2013 6:58 AM
To: electricboats-owner@yahoogroups.com
Subject: Duffy....?

Hi from Fort Lauderdale.
I purchased a used Duffy Balboa a few weeks ago, bit it does not run,
working on having the controller tested, should know in a few days.
Has anybody fitted Solar Panels to their Duffys?
If so what size?
What is the current draw from the 48 Volt motor?
I have 8 golf cart batteries and the brochure talks about a 15 hr endurance,
sounds high, would that be with an optional larger bank of say 12 or 16
batteries?
Not much tech info on the Duffy site, looking for help from other owners.
Thanks
Dag

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