Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-01-2004, 13:57   #1
Registered User
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
Aux charger ?????

I am upgrading my current inverter from 1500 watts to 3000 watts. This will power anything on board. What I would like to do is find some sort of a set up that would allow me to run a very, very small diesel engine combined with a high output alternator to put the juice back in the batteries that the inverter uses without running the main engine. Any sugestions on how to do this or anyone with experience with this kind of set would be appreciated. Thanks in advance.
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 08-01-2004, 16:49   #2
Moderator Emeritus
 
Pblais's Avatar

Join Date: Mar 2003
Location: Hayes, VA
Boat: Gozzard 36
Posts: 8,700
Images: 15
Send a message via Skype™ to Pblais
A 3000 watt inverter will in all probability drain all your batteries in short order. When going DC -> AC you lose about 20% just in the conversion. If you multiply the AMPs in AC power by 10 you'll get an idea of how long your batteries will last. A good size Microwave does serious amp hours in short order.

What you need is a genset. You run the genset and you don't drain the batteries at all. I know of nothing that can recharge batteries as fast as you drain them. Batteries don't work that fast. A high output alternator won't make 3000 watts.

The trick is to make all the power you need directly. For the best you want a low RPM diesel genset. Something in the 4KW range would probably do the trick. The expensive ones are quiet.
__________________
Paul Blais
s/v Bright Eyes Gozzard 36
37 15.7 N 76 28.9 W
Pblais is offline   Reply With Quote
Old 08-01-2004, 18:57   #3
Registered User
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
Pblais, Thanks for the reply. Your assumption is correct if the inverter is running at 3000 watts for long periods of time. But in fact the microwave only runs for a few minutes. The TV or power tools running for short periods of time will not draw down major amps from the system. We have cruised with 1500 watts for ten years now and recharge with only solar panels and wind generator. The boat is set up to operate well with the inverter and I don't want to reinvent the wheel to add a generator. A small engine running a high out put alternator instead of the main engine will easily keep up with the demands we will place on the inverter. My question was posed in the event that someone might know of a pre-packaged system or someone that has built one. We ran across a fellow several years ago that had built his own in just this way and loved it. Unfortunately we lost track of him. Chuck
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 09-01-2004, 02:25   #4
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,139
Images: 241
Small Generators

CHUCK:

A small diesel engine, driving a high output alternator; is a generator by definition.
Although much more common with gasoline engines, there are some smaller diesel generators. I don't think you'll find a diesel under 3Kw.
750 Watts = 1 H.P. - So 3Kw = 4 H.P. - BUT nothing is 100% efficient, so expect it will take a 6 H.P. engine to drive a 240A (3000W) Alternator.
Sorry, cannot think of the references (small diesels) right now. Try a "Google" search.

A 3000 Watt (3 Kw) inverter will draw approximately 240 Amps @ 12.5 VDC Battery input. Balmar makes H.O alternators in that size range, but as Paul indicates - why duplicate equipment? If your auxilliary diesel/alternator (Gen’) will be rated 3Kw (better yet 4Kw), why bother spending the money for an inverter?

It was a "good try", so keep thinking!

Regards,
Gord
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 09-01-2004, 11:52   #5
Registered User
 
delmarrey's Avatar

Join Date: Mar 2003
Location: Philippines in the winters
Boat: It’s in French Polynesia now
Posts: 11,368
Images: 122
Small Diesels

In our facilities we have a couple trailer mounted small diesels that run generators and compressors for the equipment. The thing I see being a problem is that they make so much noise and viberate a lot. Unless you have a large heavy vessel your going to hear and feel that thing running.

Myself, I have a carry-on gas genset that I keep in a locker. The new ones today are very compact and quiet. I just put mine up in the cockpit when I'm below and it charges while I'm asleep or whatever. Under sail I tie it down on the deck above the transom so I don't get any of the fumes and it just humms away. It's only a 1000w / 6 amp @ 12V but wieghs 60 lb. with fuel. The gas I have to carry for the dinghy anyway and will run 6 hrs. per gal.

Good luck on your search.........................._/)
delmarrey is offline   Reply With Quote
Old 13-01-2004, 11:07   #6
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,139
Images: 241
3.8 kW Diesel Gen'

Westerbeke has some small Diesel Generators:
WESTERBEKE www.westerbeke.com

Specifications for 3.8 BCDT:
3.8 kW @ 60Hz (3600 RPM)
Cylinders: 1
Bore: 3.2 in.
Stroke: 2.2 in.
Displacement: 18.0 cu. in.
Aspiration: Natural
Length: 24 in.
Width: 13.6 in.
Height: 21.4 in.
Weight: 183.0 Lbs. c/w Soundguard

Specifications for 4.0 BCD:
4.0 kW @ 60 Hz (1800RPM)
Cylinders: 3
Bore: 2.8 in.
Stroke: 2.8 in.
Displacement: 49.0 cu. in.
Aspiration: Natural
Length: 28.8 in.
Width: 15.4 in.
Height: 20.7 in.
Weight: 358.0 lbs.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 13-01-2004, 19:38   #7
Registered User
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
Thanks for the replies. I have done some research and found a few systems that are exactly what I am looking for. Unfortunately they are all expensive. But then what isn't on a boat
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 14-01-2004, 02:16   #8
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,139
Images: 241
Chuck:
Please share some of your newfound expertise - what have you found?
Regards,

Quote:
Chuck Baier once whispered in the wind:
Thanks for the replies. I have done some research and found a few systems that are exactly what I am looking for. Unfortunately they are all expensive. But then what isn't on a boat
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-01-2004, 19:44   #9
Registered User
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
Gord, Here is the system I am seriously looking at.

http://www.amplepower.com/products/genie/index.html
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 15-01-2004, 19:45   #10
Registered User
 
AnchorageGuy's Avatar

Join Date: Mar 2003
Location: Wherever the boat is!
Boat: Marine Trader 34DC
Posts: 4,619
And here is another

http://www.watermakerstore.com/Gener...nerators2.html
__________________
Chesapeake Bay, ICW Hampton Roads To Key West, The Gulf Coast, The Bahamas

The Trawler Beach House
Voyages Of Sea Trek
AnchorageGuy is offline   Reply With Quote
Old 12-03-2009, 02:25   #11
Registered User

Join Date: Aug 2008
Location: Asia
Boat: Roberts Mauritius 45
Posts: 32
Send a message via Skype™ to meridian@
We have an early model of Marine DC Diesel Generators - Onsite Power Systems It is a 3.5HP single cylander Kubota driving a 140A Prestolite large case alternator. Max amps at startup is 80A but this drops as the regulator cuts it back. Sits at around 65 - 70A for quite a while. Also gives us hot water through the heat echanger. 8years ago it cost AUD6000.

meridian@
meridian@ is offline   Reply With Quote
Old 12-03-2009, 11:19   #12
Moderator
 
Jim Cate's Avatar

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 21,155
Chuck,
No personal experience, but way back in 1986 friends with a Val-40 built a neat little system that fit under the berth in their aft cabin. Consisted of a 6 hp single cyl Kubota diesel which could be coupled to any of three items: a 200 amp large-case alternator, a fridge compressor or a watermaker pump. Worked for a few years, then the little Kubota wore out and they replaced it with a two cyl Kubota of a bit more power (don't remember just hdow much). This set up lasted through their circumnavigation and as far as I know is still going.

It was awkward to service there under the berth, but it was doable, and certainly did what they required.

Cheers

Jim and Ann s/v Insatiable II
__________________
Jim and Ann s/v Insatiable II, lying Port Cygnet Tasmania once again.
Jim Cate is offline   Reply With Quote
Old 12-03-2009, 17:10   #13
Registered User

Join Date: May 2003
Location: East Coast & Other Forums!
Posts: 917
Guys...Chuck is no longer here...and the question was asked in 2004. Just a heads up.
__________________

camaraderie is offline   Reply With Quote
Old 12-03-2009, 18:14   #14
always in motion is the future
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,866
Also, you guys seem to miss the point that the batteries are not in the loop when a DC generator is running. The inverter draws all (or most if alternator not big enough) input power from the alternator, not from the batteries. You still have the loss of the inverter but not the loss of the batteries.

Same for solar power or windpower: when it is used while generated, the batteries are out of the loop and efficiency improved.

We can generate 450 Amps alternator power using the two Lestec 225A Brute alternators on the main engine.

This doesn't change the fact that I prefer a direct AC generator for AC needs bigger than what my solar/battery system can supply.

cheers,
Nick.
s/v Jedi is offline   Reply With Quote
Old 14-03-2009, 19:49   #15
Registered User

Join Date: Feb 2009
Location: Missouri, USA
Boat: 17' Thistle and 13' Catboat
Posts: 28
Quote:
Originally Posted by Chuck Baier View Post
I am upgrading my current inverter from 1500 watts to 3000 watts. This will power anything on board. What I would like to do is find some sort of a set up that would allow me to run a very, very small diesel engine combined with a high output alternator to put the juice back in the batteries that the inverter uses without running the main engine. Any sugestions on how to do this or anyone with experience with this kind of set would be appreciated. Thanks in advance.
Why "diesel"? Burning fossil fuel stinks. There ought to be better ways to produce DC to charge batteries. You already mentioned solar, but to produce, say, 2 to 4 kWh (in battery language that's 200 - 400 Ah @ 12 V and 80%) - guessing that's what you might typically use daily - will take too many square feet of panel for most ships.
What else? Windmills? Stationary bikes and hamsterwheels? Ocean salt potentials? Hot air? Sigh... Yeah, maybe that stinky old 19th century diesel technology is still all we have.......
htraudes is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertise Here


All times are GMT -7. The time now is 00:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.