T-Pain Is On A Boat: RE: Re: [Electric Boats] Battery Charging

Wednesday, November 20, 2013

RE: Re: [Electric Boats] Battery Charging

Hi JB,

Sine Metu's systems sound more professional than amateur to me. Can you imagine selling a plug-in hybrid car or battery powered lawn mower to retail customers that required anything more than plugging in a single cord? My boat is like that, If I believe that the pack needs charging, usually after 4-5 day sails (every 2 months or so) I plug in one shore power cord and go get a meal and/or beverage. I come back a few hours later and watch the end of the charging cycle if the charger didn't finish up and shut itself off while I was gone. That's all. No solar or wind generation, just the shore powered ElCon charger.

I'll be interested in your regen results when you get everything working. With my 30' ketch (25' LWL) I have found that 5kts will deliver 0.1 A occasionally and even 6kts has a hard time generating more than 1A (50watts) for more than one second at a time. Since I would guess that your LWL is 20' or less, I believe that you're going to have a hard time sustaining the speed required to generate much power. But the proof is in the pudding, Your measurements on the water will tell more than my estimates.

Fair winds,

Eric

1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kWh LiFePO4 batteries

Marina del Rey, CA

---In electricboats@yahoogroups.com, <jbwrites2@...> wrote:

Damn guys, you make me feel like a rank amateur!

Sine Metu's dedicated 12 battery, 12v, 40Ah LiFePO4 battery configuration consists of 3 banks of 4 batteries in series, bringing them up to 48v; then the 3 banks are hooked up in parallel to build up to 120Ah. All of which feeds the 3.5Kw electric drive aboard a 50 year old, 24 foot, 5,500 pound displacement sailboat in San Diego.

All of this is BMS controlled.

Once the system is completely setup, I hope to charge everything from the drive feed's bus bar by an AmpAir 100 watt wind generator (guessing 90%) and by ReGen (10%) from the drive while sailing, or by a 48v, 15A charger at the dock. I'll get back to you with real performance numbers, hopefully, by Christmas, but the shore power charging system seems to work keeping everything topped off and happy. The engine's controller is being upgraded currently by Electric Yachts and not hooked up, so I have not been putting any real loads on the system yet.

Oh, and the 12v house system is charged from the 48v bank via a Morningstar 15A MPPT and/or bypassed entirely by the 48-12v Sevcon DC-DC converter (installed as a backup). 12v loads are low: Bilge pumps, VHF, navigation and cabin lights (all LED), stereo and navigation equipment.