Re: [electricboats] 15 KW DC l electric conversikon

Graeme,

I ran some experiments on a a Catalina 22 with a Torqeedo 4R - which is probably the closest recorded data you may find with that motor...

At 4 to 4.5mph, I was burning 800-1000W.   At 48V, that's around 20A.

Your range will depend heavily on your battery chemistry.   If you are using AGM or Lead Acid batteries, assume maybe 50% of your rated amperage - so a 130A bank might get you 65AH, so you should comfortably be able to get 3 hours of cruising, assuming you limit yourself to 1000W - which will hopefully push your boat close to 4mph.

Does that help?

Here are the test numbers from a run with the 48V Torqeedo on the C22:

You can see how the required power increases dramatically above 4.5mph.  Hull speed for a 22' boat is about 6mph, if I did the math right...

Power            Speed

160w                2mph

500w                3.3mph

800w                4.0mph

1000w              4.5mph

1500w              5.3mph

2000w              5.8mph

3000w              6.5mph

On Sunday, February 9, 2020, 01:12:19 PM CST, Graeme Ross <graemealross@gmail.com> wrote:

Sorry I meant 130 amps

On Sun, Feb 9, 2020 at 1:25 PM Graeme Ross via Groups.Io <graemealross=gmail.com@groups.io> wrote:

Hi I bought a Torqeedo 4.0 with 4 12v 30 amp batteries. The boat is a 23ft Bayfield sailboat weighing 3500 lbs . I am wondering the approx. range I can get at 4 knots. The hull speed is 6 knots.   Thank you Graeme Ross