Myles
Thanks for the info. While my Zivan will push the boat for hours very nicely. I'm still operating the Honda in eco mode. So there is still a few more amps I could tap if I had another power supply in the mix. I don't need a charger I've got the Zivan and the Dual Pro already on board. Just a small 48 volt supply that will not trip out the Honda when used with the Zivan. Something like you have with an output current adjustment sounds like it would fit in rather nicely. I have not looked at the numbers but, I expect some thing in the 500 watt range might be about right, I like you would only use it for extended motoring. Might be something I'll research over the winter. As it's sailing time now!
Capt. Mike
Sent from on board BIANKA
http://biankablog.blogspot.com
The LESTER is a Lestermatic 36v/20a golf cart battery charger. It’s a ferroresonant charger with built-in automatic controls that essentially make it a 2-stage CI/CV charger…steady 20amps until about 45.1v or so, then keeps charging while holding the voltage constant until charge current gets below 5amps or so, then it shuts down. This charger is my usual all purpose charger.
The Vicor is simply a power supply unit. It’s a Vicor Megapac unit (110v/220vAC in, 300vDC to a backplane) populated with 1 – 48v/4amp Driver module in parallel with 4 --- 48v/4amp Booster modules. These share the load between them and they’re designed/built to have current limited outputs so that it will deliver 20amps max from 0v up to 48v (or whatever I tune it to), then the output will hold at constant voltage. So it acts as a CI/CV charger except that there’s no provision to automatically shut down. I only use this charger if needing that extra 20amps of charge current while underway.
Both of these chargers are effectively in current limit when used underway since the voltage is always 37v or less while running.
They each have fused outputs and being current limited I don’t need to do any more than plug the Vicor into the battery bank with 50amp Anderson connectors and the Lester in with a standard Lester plug/jack. And I made sure that they’re connected to the right side of the current shunt so that the Link10 keeps track of the charging power. Yes, they are effectively paralleled, but again, the Vicor is only ever used while underway with the generator. At the dock, it’s just the Lester.
-Myles
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Capt. Mike
Sent: Sunday, August 29, 2010 4:18 PM
To: ELECTRIC BOAT GROUP
Subject: Re: [Electric Boats] Re: battery bank upgrade
Miles
I'm curious. Were your Lester and Vicor chargers brute force chargers? By that I mean more like power supplies and not sophisticated multistep chargers like the zivan, elcon etc... Also how did you hook them to the battery bank? Did you simply parallel them or did you isolate them with things like diodes. Sounds Like you've got a good setup for lead acid batteries and using the Honda for extended motoring.
Sent from on board BIANKA
http://biankablog.blogspot.com
From: "Myles Twete" <matwete@comcast.net>
Sender: electricboats@yahoogroups.com
Date: Sun, 29 Aug 2010 11:41:40 -0700
To: <electricboats@yahoogroups.com>
ReplyTo: electricboats@yahoogroups.com
Subject: RE: [Electric Boats] Re: battery bank upgrade
Thanks---you got me… my observations did not include measuring AC power to the chargers. I did measure a steady 40amps DC into the nom. 36v battery bank however (Link10 meter measurements). Likely I was pushing the EU2000i past its rated 1600w steady AC output since I don’t think the 20amp Lester and the 20amps from my Vicor Megapac were being generated with above 85% efficiency combined. I do know that the generator would not run continuous when I bumped the Megapac output up to 24amps for 44amps total---at 40amps, all was good for 17hours of 45-mile Columbia River upstream cruising over 2 days.
I suppose the genset was putting out about 1700w continuous on that trip.
-mt
From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of Eric
Sent: Friday, August 27, 2010 10:41 AM
To: electricboats@yahoogroups.com
Subject: [Electric Boats] Re: battery bank upgrade
Myles,
While I'm not disputing your observations, I'd like to clarify some of the math. Assuming a maximum of 1600W in and 1440W out, the charger has to operate with at least 90% efficiency. There are some chargers that will do this, but many chargers like Zivans, Dual Pros and ProMariners are not that efficient.
Since charging voltages are higher than resting voltages, I think that a conservative average would be 13.8V per 12V battery (charging voltages are often higher), so 1440W divided by 55V is closer to 26A. I know that it is only 4A difference, but that is 13% less than quoted.
That said, I'm on your side. I think that a generator like a Honda EU2000i (mine is a Yamaha EF2000iS), matched with an appropriately sized efficient charger, is a reliable way to deliver between 20A and 25A into the batteries or drive system for as long as you've got fuel. Like you said, this can be used to "limp" home at slower speeds, or to extend the range of your existing battery capacity at somewhat higher speeds.
For me, that is my backup to my auxilliary.
Fair winds,
Eric
Marina del Rey, CA
--- In electricboats@yahoogroups.com, "Myles Twete" <matwete@...> wrote:
>
> DRMSUDO noted: "Yes, I own a honda 2000. In my experience the generator is
> only good for charging. I have tried to use it to drive the dc motor and it
> is just not powerful enough.. "
>
>
>
> The Honda EU2000i can continuously output up to 1.6kw. With enough charger
> onboard, I've successfully delivered 1.44kw into my pack for 17hours while
> cruising against the current. With a 48v pack as you have, this would be
> just about 30amps. This could double your range at 5knots or allow you to
> cruise indefinitely at up to 4knots. Attempting to draw any more than this
> power continuously will stop the generator, so you'd have to have a charger
> that is either adjustable or otherwise limited in the energy it draws. So
> YES, while the generator is only good for charging, that you can deliver up
> to 30amps into your battery bank with it means that you can draw up to
> 30amps less from your pack if you ran your generator and a properly sized
> charger while in a pinch.
>
>
>
> -Myles
>
>
>
> ._,___
>
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