Electric outboard drive for small cruisers

<< First  < Prev   1   2   3   4   5   ...   Next >  Last >> 
  • 06 Jun 2020 15:10
    Reply # 9018982 on 9018853
    I wrote:

    And.. it would actually be nice to get a 20-30Ah portable battery pack for the dinghy, but they'd need to be 3C cells (to draw 60-90A continuous). Maybe some day...

    Quickly browsed through the AliExpress store where I bought my cells. If this product description is to be believed (looks like the same line that I have) these 20Ah cells can handle up to 10C (200A) continuous discharge, for €245. Slap on a €58 Daly BMS and you have a 24V/20Ah (~500Wh) battery for ~€300. Judging from today's trials 5A should be enough power to drive you along in calm conditions, so the range would be up to 4 hours, although under average conditions it would probably be between 1-2 hours. Unfortunately the cells are only available shipped from China so I wouldn't have time to wait for them to arrive. Another time.

  • 06 Jun 2020 13:52
    Reply # 9018853 on 8809939

    Had a 3 hour window here without rain so decided to do some sea trials after all! Worked pretty much as expected. Had 26.1V to start with and ended up with 25.9V. Only ran a really short while on full throttle since the voltage under load dipped down to 24.1-24.2 and didn't want to push it, so I mostly ghosted along, trying different speeds, getting the feel for the motor behaves is at 1A, at 5A, at 10A, 20A... with some running up to 80-85A (with voltage under load dropping to about 25.2-25.4V).

    One annoyance is that the throttle turns the opposite way compared to a regular outboard so I found myself reversing when getting underway and increasing the revs when I wanted to slow down. This is gonna take a bit of time getting used to, unless I dare to pick the throttle apart and switch it around...


    Would be an excellent driver for this 4.2 meter aluminium boat, if only you wouldn't have to carry that heavy battery pack every time..! I'm all sweaty now. So would basically need to be able to charge it at the boat.

    And.. it would actually be nice to get a 20-30Ah portable battery pack for the dinghy, but they'd need to be 3C cells (to draw 60-90A continuous). Maybe some day...

    That concludes this chapter, now I can take the battery apart until it's time to fit it to Tua-Tua.

  • 05 Jun 2020 21:19
    Reply # 9018044 on 8809939

    Figured out how to wire the BMS:

    It was a bit of a challenge due to there first of all being two B- and P- wires (the blue and black ones from the BMS) instead of one in the instructions (since most other Daly BMS's) but they're just doubled, instead of using a thicker gauge I suppose. And secondly due to the sloppy Chinese instructions in questionable English. But I managed in the end and all voltages were correct!

    Next up, as I bought a 150A fuse locally yesterday, I connected the Victron charge controller and the ammeter and gave the electric motor a dry run. Worked just as it should, showed a 3.3A draw on maximum revs.

    Unfortunately it's been rainy here today and will continue tomorrow, so splash tests will have to wait. And should probably build a better battery box in the meantime anyways. And I will need to get started on sewing the sail. Rain-free days aren't expected here until Wednesday.

    Edit: For the production version I think I will wire the solar charge controller directly to the battery, bypassing the BMS. This in order to protect from the case where the BMS shuts off the batteries for whatever reason (low/high voltage), which would potentially kill the SCC if the panels are connected. Although it might be able to handle it since I have 24V panels, it would be more critical if I had something like 96V of solar feeding into the controller, with nowhere to discharge. From what I've read.

    Last modified: 05 Jun 2020 21:24 | Anonymous member
  • 04 Jun 2020 14:19
    Reply # 9014607 on 8809939

    BMS arrived today and now I'm itching to go try out the motor, but it's probably not a great idea to do it without a fuse or a breaker (which hasn't arrived yet). :|

  • 03 Jun 2020 18:41
    Reply # 9012767 on 9006703
    I wrote:

    Yay, my 24V 190Ah LiFePO4 bank has finally arrived! Now I just need to wait for the 150A breaker to arrive and I can go and give the electric motor a go.

    They arrived well balanced, as advertised, with voltages all between 3.267-3.269V.

    Grab your own at AliExpress! Price for the above cells is €1325 right now, I paid €1180 back in April.

    Oops, I was checking the price shipped from Poland. If you can wait longer (2 months vs 2 weeks from Poland) and order from China instead like I did, then that package is €574.05 + 574.05 = €1148.10. Add a BMS for €112 and you have a 4.5 kWh battery bank for a total of €1260.

    I also got a Victron temperature sensor (~€50) as I won't have other charging methods than solar so I don't need low temp cutoff on BMS level.

    Cells are held together in two groups of 4 (for easier handling, 2x14 kg) with double-sided tape (gives a bit of spacing between the cells) and hose clamps. BMS cleared through customs yesterday so should arrive any day now. I'm getting excited here!

  • 01 Jun 2020 14:14
    Reply # 9006703 on 8809939

    Yay, my 24V 190Ah LiFePO4 bank has finally arrived! Now I just need to wait for the 150A breaker to arrive and I can go and give the electric motor a go.

    They arrived well balanced, as advertised, with voltages all between 3.267-3.269V.

    Grab your own at AliExpress! Price for the above cells is €1325 right now, I paid €1180 back in April.

  • 30 May 2020 21:40
    Reply # 9003608 on 9002534
    Anonymous wrote:

    While surfing the web looking for website "looks" that might suit the JRA, I happened upon this:

    https://www.temofrance.com/en_GB/

    Maybe not applicable to small cruisers, but I've been thinking for some time that this is what electric propulsion for a small dinghy ought to look like - more like the "longtail" motors. Having tried unsuccessfully to get a small inflatable off a beach with a regular electric outboard, I was thinking of converting it to the longtail format.


    Bonjour

    I've seen the prototype at the Paris Boatshow in December 2019. It looks impressive.

    I was thinking about it for Mingming.

    Eric

  • 30 May 2020 07:55
    Reply # 9002534 on 8809939

    While surfing the web looking for website "looks" that might suit the JRA, I happened upon this:

    https://www.temofrance.com/en_GB/

    Maybe not applicable to small cruisers, but I've been thinking for some time that this is what electric propulsion for a small dinghy ought to look like - more like the "longtail" motors. Having tried unsuccessfully to get a small inflatable off a beach with a regular electric outboard, I was thinking of converting it to the longtail format.

  • 28 May 2020 21:08
    Reply # 8998853 on 8809939
    Anonymous member (Administrator)

    Darren, I am really impressed by that 2kW motor. It just reminds me og that technology has left me behind.  Anyway, I was never a whale on motors.

    Cheers,
    Arne

    Last modified: 30 May 2020 08:33 | Anonymous member (Administrator)
  • 28 May 2020 20:07
    Reply # 8998731 on 8809939

    David, 

    The big prop makes your new motor very much like a modern British Seagull.  They were one of the few manufacturers that got outboards right for displacement boats, with a large slow turning prop.  Of course, you'll now do it without the trailing cloud of smoke, crazy exposed flywheel, or incredible racket.

    Glad to hear it is working out well.

<< First  < Prev   1   2   3   4   5   ...   Next >  Last >> 
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software