Friday, January 3, 2014

Re: [Electric Boats] DIY Hybrid System Questions

 

A 5 mile trip at "low speeds" will be around 2 hours. Is this one way or return?
You would definitely need the 200AHr pack to operate under battery alone. 

As it stands, with a 72AHr lithium pack, you're looking at about 57AHr usable. 

I am assuming a 48V nominal voltage do that is a 2.7kWHr pack. 


On Jan 3, 2014, at 9:18, <luke.wolbrink@gmail.com> wrote:

 

I'm in the middle of converting my 1971 Tartan 27 over to electric (22'LWL, 8.5'Beam, 7500#displacement, 5kw bldc motor w/2:1 reduction) in Chicago on Lake Michigan. I'm beginning to run out of funds for the project and am well short of my 200AH LiFePo4 battery pack; currently 72AH. Since the boat is primarily a daysailer with the motor being used for in/out of the harbor and perhaps to motor in if the wind dies and I have a schedule to keep; I figure that 72AH will be fine. I would however like to be able to go on longer cruises like a lake crossing or a trip to Milwaukee; to do so I would feel more comfortable with a greater range on my motor. I'm considering a setup with a small gas generator (2kw max) that hooks into my shorepower plug and powers a 48v switching power supply (1kw) that will drive the motor at a low speed for some extended range. Now for the questions:


1) When on the power supply can I run on batteries as well or is there concern about backfeeding and damaging the batteries?
1a) If it's ok to run both at once, can I charge my batteries with the normal charge hooked into my shorepower system and run them at the same time for a few more watts of power?
2) With a switching power supply can I get away with a standard hardware store generator or will I need to get one of those pure sine-wave generators? 
3) The cost for power supplies goes up sharply after 1kw, about what speed could I expect from 1kw of power with my 13x8 2blade prop? (I know the prop isn't ideal but again the budget is tight and I'll need to stick it out)
4) The longest run I need to make is up the Chicago river and through the locks. This is about a 5mile trip at pretty low speeds (2kts) and little current, will my 72AH make it? If not I'll need to hurry up and make the hybrid a higher priority.

Thanks in advance,
Luke

__._,_.___
Reply via web post Reply to sender Reply to group Start a New Topic Messages in this topic (2)
Recent Activity:
.

__,_._,___

No comments:

Post a Comment