[electricboats] Electric Outboards and trolling motors on a 10' RIB

Below is the data that I've recently collected, comparing several different "electric outboard" and trolling motor options.

The boat for all tests was a West Marine 10' RIB 310, single fiberglass bottom.

Speeds were monitored using Navionics, and averaged for both up and down wind, in a relatively protected marina environment.  Battery data was collected using a Victron 150A SmartShunt.

MOTOR SUMMARY:

Motor              Voltage              Max Speed              Max Power
Torqeedo 2T      24V                  4.8Kn                     1200W**   (Motor testing limited at 1200W due to battery limits)

About $4000, rated at 2400W

Hangkai               48V                3.8Kn                      1000W About $330, Rated 1000W - VERY Noisy

Minn-Kota 35#     12V                2.3Kn                      410W

Newport 55#          12V              3Kn                          550W About $200, Rated 50A@12V

Summary thoughts:

For speed and power, the Torqueedo 2T was clearly on top.  Unfortunately, the 24V Torqeedo is about $4000+.   Finding 24V batteries that fit in a standard battery box is a bit of a challenge, but do-able.  Currently, they are running about $300 for a 60Ah battery.   Torqeedo offers other smaller motors with integrated batteries - but they are still have  about a $2000-3000 price tag, and spare batteries are VERY expensive.

The Hangkai is a VERY cost effective answer for a 48V outboard electrict motor.  However, this motor has a VERY touchy throttle, is extremely noisy, and didn't perform significantly better than the 55# Newport trolling motor.

While the Newport 55# won't get you anywhere fast - it does seem to do a decent job, and should be sufficient for getting the dinghy from boat to shore (as long as there isn't a strong/fast current).  12V lithium batteries are easy to obtain, and a very common voltage to work with.  Overall bang for the buck in terms of a nicely performing, low cost motor with an easy to purchase / replace battery seems to be the Newport.  Just don't be in a hurry.

Note that while the Torqeedo 2T was the fastest option - running at 1200W will kill a 60Ah 24V battery in about an hour.  I would want to have at least two batteries minimum.  

The Newport 55# trolling motor should run in excess of 2 hours on a single 150Ah 12V battery.  A second, smaller, lighter, less expensive 100Ah battery can be brought along as backup for plenty of range.