Hybrid Boat

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
Post Reply
bdickens
Posts: 42
Joined: Sat Dec 08, 2001 1:01 am
Location: Newark, De
Contact:

Hybrid Boat

Post by bdickens » Mon Aug 31, 2009 6:23 pm

We have been running a small boat on an electric outboard we cobbled together using a design from Glen-L. But we are about to start building a second boat and we wanted to go electric. So we will have two electric outboards connected to 4 lead acid batteries (48V). We will be including a set of solar panels to charge the batteries at rest, and a small wind genertor on the dock.

But we will also include a gas powered generator just in case we end up running out of juice and need to make it back. I'm not interested in having a gas powered outboard, just in having a 5000 watt on board generator to pump me back up or give me a bit more range in a pinch. But I have a couple of concerns.

1) Charging from an AC generator - I will be using pretty standard marine chargers. Any issue charging them while running the motors ?
2) Our current charging scheme charges each battery independently. But since we have 2, we are generally ok. If I have four, any better schemes ?

Any other thoughts would be welcome. No need to get detailed, if you can aim me in the right direction, I have no problem doing my own "homework". But you can eliminate a lot of dead ends up front.
Thanks

User avatar
kheston
Posts: 348
Joined: Wed Dec 03, 2003 1:01 am
Location: CA
Contact:

Re: Hybrid Boat

Post by kheston » Mon Aug 31, 2009 7:12 pm

I'm in the process of converting this to charge each of the 12v batteries in my 48v bank:
ImageImage

I'm making plastic bushings for the all-thread you see in the pics to separate the grounds. There's a lot of moving parts to deal with in this design, but it gives me the control I want and it was cheap to build (Craigslist engine, junkyard alternators) <$500. It puts out about 2.5kw with standard 55a alternators. If you use 100a alternators instead, you'd get much closer to the 5kw you're looking for.

HTH
Kurt - SF Bay

Robert Reed
Posts: 2276
Joined: Wed Nov 24, 2004 1:01 am
Location: ASHTABULA,OHIO
Contact:

Re: Hybrid Boat

Post by Robert Reed » Mon Aug 31, 2009 7:54 pm

mmmmm
5 KW? That would take a 8 or 9 HP engine running flat out to produce that. Do you really need that much power? Even if the batteries were floatcharged while running, thats a lot of current output since the actual charging current would only be a small fraction of the total output. Seems like a lot of current going into the motors. When you say electric, I conjure up commercial auxilliary fishing motors which are not very big. What size are they?

User avatar
Externet
Posts: 1862
Joined: Fri Feb 01, 2002 1:01 am
Location: Mideast USA
Contact:

Re: Hybrid Boat

Post by Externet » Tue Sep 01, 2009 6:54 am

Hello bdickens. First, congratulations on the project. Nice. I would say the standard marine chargers should take care of the job even with motors running if they are current limited.
A selector switch for -charge only/run only/both- would be convenient to implement, as depending on the needs of the moment, you can get to port in better form.

The independent battery charging mode is right; but coming from a 5KW AC generator, implies 2 or 4 chargers or switchmode power supplies at 14V capable of ~40 Amperes continuous duty. On the other hand, if it was a DC generator, you could not easily isolate the independent battery charging.

Just avoid pushing running everything beyond ~70% of ratings.

Kurt's approach seems convoluted but is not, probably chosen by what had available and provides reliable redundancy in belts, alternators, wiring... I would consider it as a great alternative to 4x marine chargers : You get rid of the AC generator and the marine chargers in exchange for inexpensive regulated power sources, easily replaceable/serviceable with less risks of 'high' voltage in a wet environment.

Keep us informed :grin:
http://www.psnw.com/~jmrudholm/etekoutboard.html
http://www.parsunelectricoutboard.com/
http://www.briggsandstratton.com/engine ... px?pid=171
Miguel
- Abolish the deciBel ! -

bdickens
Posts: 42
Joined: Sat Dec 08, 2001 1:01 am
Location: Newark, De
Contact:

Re: Hybrid Boat

Post by bdickens » Tue Sep 01, 2009 9:21 am

First, thanks for responding. Some impressive work.

kheston - Wow. I would not have even thought about that approach but I have to say, it has some appeal. And as Robert Reed correctly pointed out, I may not really need that much juice. 2.5kw might just get me there. And I have to admire the approach. Elegant.

Robert Reed - The plan was to run 2 motor pods, with at least 9-12hp in each. So I'm looking at pulling about 200A @ 48v but as you mention, I probably don't need the full amount. We were looking at this one ( http://www.craftacraft.com/electric_outboard_video ) with some envy. Right now, it is a single motor and looks a lot less professional.

Miguel - Good points. A switch to isolate would be nice. You did lay your hands on one major concern around high voltage.

My son is working on the scale model, and the software for the monitors. I have the cheerful job of powerplants (rock/paper/scissors let me down) so if any other thoughts hit, pass them on.
Thanks again

Post Reply

Who is online

Users browsing this forum: No registered users and 36 guests