Re: [electricboats] Lake Test - 13' plywood runabout with Torqee

Nice ride!

Capt. Carter

www.shipofimagination.com

On Wed, Jun 24, 2020 at 4:45 PM, john via groups.io

<oak_box=yahoo.com@groups.io> wrote:

On Monday, 6/22/20, I conducted my first on the water Lake trial with my electric conversion, "Mischief".

Mischief is a home built plywood runabout, currently powered with a Torqeedo 4R outboard.  Specs are below:

LOA:  13' 4" (without motor)

Beam:  5'9"

Weight:  about 300-400#

Draft:  approximately 6-7", with motor up.

Theoretical Hull Speed:  4.9mph

Motor:  Torqeedo 4R electric outboard (with remote steering)

    48V, max 4000W input

Battery:

  Main battery bank:  48V 50Ah eBike battery system from BTR (ordered on Amazon) (approx $900)

  Backup / get home battery:   48V 20Ah eBike Battery system from BTR  (under $500)

Both battery systems were bench tested.  For each test, the battery was fully charged, and then connected to sets of #9006 12V halogen light bulbs (4 bulbs in series gives a 48V load at about 4A).  Time and voltage were recorded periodically until the battery BMS shut down the voltage output from the battery.  Tests were conducted with 4, 8, and 16 bulbs (max was 4 parallel sets of 4 bulbs, approximately 800-900W).  I have the data on these tests, if anyone is interested.

At the lake!!

First test was a static test of running the boat at the boat ramp (the motor needs to be in the water when running).  The motor was run at 1000W, and ran for approximately 45 min before the BMS dropped out, on the 20Ah battery.  The BMS dropped out at about 48V.   (The BMS on the 50Ah battery drops out at around 40V.)

The first "on the water" test lasted for approximately an hour, and used approximately 30-50% of the capacity of the 50Ah battery bank.

Performance of the boat consistently met expectations.  Handling was great.  As long as you're ok with a walking speed cruise - the boat performed very well.

 Volts Amps Watts MPH

 58.2    5.15 300         3

 57.0 6.5         370         3.5

 56.8 8.80 500          3.9

 57.7 10.4 600         4

 56.0 15.71 880         4.9

 57         17.54 1000 5

 56         26.79 1500 5.7

I've attached a couple of pictures of the boat.  Please let me know if they don't come across.

If anyone would like more details, feel free to contact me.

John