One small correction. You have a typo on your page the green Galaxy is
DC Motor Controllers. The DC/DC converter was just called: 48-12V DC-DC
On Jun 19, 2009, at 5:03 PM, aweekdaysailor wrote:
>
>
> Thanks Denny,
>
> I have played with several different options, and was always worried
> about the un-equal discharge - I thought that also decreased your
> usable range because the string voltage can drop precipitously when
> the low battery reaches it's limits - well before the others do. Is
> this not the problem I imagined?
>
> The solution I ended up with is both cheap and hopefully reliable.
> I'm using the inexpensive 10amp Green Galaxy converters available
> from Thunderstruck. But running in parallel to increase the
> amperage. As far as I can tell, there's no practical limit to this.
> Using the technique you could get say 30amps with 3, but add 1 more
> for n+1 redundancy and still stay around ~$100. Failure is graceful
> this way - you could lose 3 and still have enough for nav lights for
> example.
>
> http://sites.
>
> -Keith
>
> --- In electricboats@
> wrote:
> >
> > Keith,
> >
> > I just got a chance to look over your new site - great job!
> >
> > As we both know, there is a lot of "beta testing" involved in
> setting up an electric drive system. The components don't always
> work so well together and the manufacturer'
> sketchy, irrelevant and sometimes just wrong. (like the MARS PMAC
> rpm per volt data).
> >
> > Here's something I learned along the way about charging and
> battery banks that could save someone else grief. Feel free to
> incorporate into your website if you think it's appropriate.
> >
> > Often a battery bank is tapped for a lower voltage than the whole
> string provides. For instance in a string of (4) 12v batteries
> supplying 48v to the motor you might connect one of the batteries to
> a 12v distribution panel to supply power for lights, stereo, GPS,
> etc. This works fine but it means that one of the batteries will be
> discharged down lower than the other three. This is not a problem IF
> that 'special' battery is charged independently but putting one 48v
> charger on the whole string will not fully charge the lower battery.
> >
> > Wiring a Link 10 meter or other battery 'fuel' gage can cause this
> same problem, even though their power usage is measured in
> milliamps. In the case of the Link 10 the instructions (and their
> tech support) say to wire a 12v or 18v power supply directly to the
> battery bank so the meter is always powered as it can be damaged if
> the wrong wires are powered up first. This works fine BUT that small
> 25 ma current is being drawn from just part of the bank 24/7 and
> adds up to a significant ah drain over several months. Without
> independent charging the bank will slowly get unbalanced.
> >
> > Another solution is to use a motor voltage to 12v transformer and
> power all 12v loads off the transformer. This means the 12v loads
> are shared equally by all the batteries. This adds a couple of
> hundred dollars to the cost of the system but little weight or
> complexity.
> >
> > A third solution is to use a separate 12v battery with its own
> dedicated charger just to power the house loads. This is much
> heavier and may be either cheaper or more expensive depending on the
> quality of the house battery and charger used. You also have to
> remember to plug in two chargers.
> >
> > Denny
> >
> > PS: Thanks for the link to my website.
> >
> >
> >
> >
> > ----- Original Message -----
> > From: aweekdaysailor
> > To: electricboats@
> > Sent: Sunday, June 14, 2009 3:34 PM
> > Subject: [Electric Boats] Beginners Guide
> >
> >
> >
> >
> >
> > Lately I've found myself and others answering the same questions a
> lot, and one of the reasons of course is that, while a ton of
> information is available here, it's somewhat daunting to get at (if
> Yahoo's group search is even working which seems spotty at best).
> Many of the answers are buried in long, intimidating threads
> containing much debate and little resolution.
> >
> > With that in mind, and somewhat based on earlier FAQ efforts - I
> threw together a Beginners Guide. It's got a lot of my own, possibly
> incorrect, opinions and observations, so I didn't want to represent
> it as an FAQ for this group. But it's there, and might be a
> convenient resource to point the NOOBs (newbies) at vs repeating the
> same responses to the group.
> >
> > http://sites.
> >
> > Not complete by any means, but a good start I think. If anyone
> wants to contribute a specific section please contact me offlist. In
> particular I think there is a crying need for parts lists and
> suppliers so if anyone can provide documentation on their
> installation that would help.
> >
> > -Keith
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
[Non-text portions of this message have been removed]
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch format to Traditional
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
No comments:
Post a Comment