[Rhodes22-list] Peukert's Equation
elle
watermusic38 at yahoo.com
Sun Jan 28 18:06:11 EST 2007
B.,
If you can't clarify, obfuscate.
Go sail.
elle
--- Bill Effros <bill at effros.com> wrote:
> L.
>
> (A small woman with a short fuse?)
>
> Here is an explanation of Peukert's Equation that I
> have not simplified.
>
> If the mathematical symbols do not come through, go
> to this site:
>
> http://www.smartgauge.co.uk/peukert.html
>
> Bill Effros
>
> *A proper explanation of Peukert's Equation
> (Peukert's Law)*
>
> Mr Peukert first devised a formula that showed
> numerically how
> discharging at higher rates actually removes more
> power from the battery
> than a simple calculation would show it to do. For
> instance discharging
> at 10 amps does not remove twice as much power as
> discharging at 5 amps.
> It removes slightly more. Therefore a 100 amp hour
> battery (at the 20hr
> rating) could provide 5 amps for 20 hours, but it
> could not provide 10
> amps for 10 hours. The available time would actually
> be slightly less.
>
> Mr Peukert wrote down a formula for describing how
> much less time would
> be available. Please note that in the first
> paragraph I say "Mr Peukert
> first devised a formula for....". This is because he
> is generally
> regarded as being the man who first discovered the
> phenomenon. This is
> incorrect. The effect had been known for many years
> beforehand and was
> first noted by a certain Mr Schroder several years
> before Peukert
> devised his formula. Mr Peukert simply quantified it
> in a way that had
> never been done before. However the effect is now
> known as Peukert's
> effect, the formula for calculating it is known as
> Peukert's equation,
> and the important number, unique to each battery
> type, that is put into
> the equation in order to perform the calculation, is
> known as Peukert's
> exponent. Note that Peukert's exponent changes as
> the battery ages.
>
> Please note that there are two ways of looking at
> this effect. We could
> say that discharging at higher currents reduces the
> total available
> power that can be got out of a battery. So a 100 amp
> hour battery might
> become say an 80 amp hour battery at higher
> discharge rates. This is
> technically the correct way of looking at it.
>
> However it is easier to assume that the total
> available power in the
> battery remains identical whatever the discharge
> rate. But that
> discharging at higher rates removes more amp hours.
> This is the method
> of explanation used throughout this website and on
> the Peukert
> calculator spreadsheet.
>
> Note that whichever method is used, the figures and
> effect remain
> identical in both cases. It's just that we consider
> the second method to
> be easier to understand and "get your head round".
>
> Peukert's equation can be found all over place. On
> the internet, in
> battery data sheets and documents, in battery sales
> literature, in
> battery monitoring equipment manuals etc. It is
> usually written as I^n T
> = C
>
> Where:
>
> I = the discharge current in amps
> T = the time in hours
> C = the capacity of the battery in amp hours
> n = Peukert's exponent for that particular battery
> type
>
> The idea is that the time (T) that a certain battery
> can run a certain
> load for can be calculated by rearranging the
> equation to read T = C/I^n
>
> Please note that this equation, seen all over the
> place, is wrong.
> Actually, I'd better rephrase that. The equation is
> not wrong. But the
> way people attempt to apply it to the battery
> capacity is wrong.
>
> This equation cannot be used on batteries that are
> specified at (say)
> the 20 hour rate, or the 10 hour rate or any other
> "hour" rate. It will
> not work. For an explanation of why and what
> equation you need to use
> read the rest of this article.
>
> Alternatively go here
> <http://www.smartgauge.co.uk/peukert3.html> to
> find a suitable solution without understanding why.
>
> Even a cursory attempt at using it will show that it
> simply cannot be
> correct.
>
> So let's try using this equation and see what we
> get.
>
> The first problem we come across is that the battery
> capacity does not
> state any type of rating. Is this the 100 hour rate?
> the 50 hour rate,
> the 20 hour rate? or some other rate?
>
> Most people assume it to be the 20 hour rate so we
> shall do the same here.
>
> Take a battery rated as being 100 Ahr (at the 20
> hour rate - the most
> usual specification) with a Peukert's exponent of
> 1.3 (a typical figure
> for a deep cycle wet cell).
>
> The rating on this battery means it can provide 100
> amp hours in total
> at the 20 hour discharge rate. That is what the
> rating means. This
> battery, when new, can provide 5 amps for 20 hours.
>
> However, if we plug these numbers into the usual
> Peukert's equation (the
> one that we see all over the place) we get:-
>
> T = C/I^n
> T = 100/5^1.3
> T = 100/8.1
> T = 12.3 hours - yet we *know*, from the
> specification, that it can
> provide this current for 20 hours!
>
> Just plugging the battery's actual known capacity
> onto the equation
> gives us the wrong result.
>
> Ok, let's do a quick check on this. Let's do exactly
> the same
> calculation but this time we will use 2 of the same
> battery i.e. 200 amp
> hours, and the load will be exactly twice as much
> i.e. 10 amps instead
> of 5 amps. Common sense (and experience and
> calculations) tells us that
> the run time will be exactly the same as a single
> battery at 5 amps load.
>
> T = C/I^n
> T = 200/10^1.3
> T = 200/19.9
> T = 10.0 hours - But we all *know* that it should be
> the same as the
> above example
>
> Let's just double check on this to make sure we
> haven't missed something.
>
> The first result above suggests that this battery
> can actually only
> provide 5 amps for 12.3 hours. That makes it a 5 X
> 12.3 amp hour battery
> at this discharge rate. That means this equation
> tells us it can provide
> a total of 61.5 amp hours when discharged at 5 amps.
>
> So let's plug these new numbers into the equation
> and see where it gets
> us:-
>
> T = C/I^n
> T = 61.5/5^1.3
> T = 61.5/8.1
> T = 7.6 hours - So it has now decided something
> completely different.
>
> Everytime we try to use this equation it makes the
> battery smaller!
>
> Clearly there is something very wrong with the
> equation.
>
> Well there is, and there isn't. There is nothing
> wrong with Peukert's
> equation. It's simply that this is not how it should
> be used. Peukert's
> equation shows the relationship between varying
> discharge rates. It
> shows how the run time will be affected by changes
> in the discharge
> current. It shows how they affect the battery run
> time and it's apparent
> capacity. But it doesn't do this in relation to a
> specific battery
> capacity. That is not how he intended it to be used.
> It was to be used
> to calculate how increasing the charge current by,
> for instance, a
> factor of 3 would affect the available run time. For
> instance assume a
> discharge current of 10 amps gave them 40 hours run
> time from a certain
> battery bank. This would mean that 10^n X 40 hours
> amp hours had been
> consumed. This gave them their capacity at the 40
> hour rate. The above
> equation could then be used to calculate the run
> time at say 20 amps.
> Used that way it works quite well.
>
> Whilst Peukert's equation is correct, it is not
> written in a way to
> enable it to be simply applied to a certain battery
> in the way they are
> usually rated. In order to do this we need to modify
> the equation so
> that it takes into consideration the way the battery
> capacity is quoted.
> The modified equation is:-
>
> T = C/(I/(C/R))^n X (R/C)
>
> Where:
>
> I = the discharge current
> T = the time
> C = capacity of the battery
> n = Peukert's exponent for that particular battery
> type
> R = the battery hour rating, i.e. 100 hour rating,
> 20 hour rating, 10
> hour rating etc.
>
> What we have done here is modify the equation to
> operate effectively
> given the battery capacity and hour rating.
>
> This formula works. However, you must ensure that
> the correct hour
> rating is inserted. If the battery capacity is
> quoted at a different
> rate then this equation will give very misleading
> results. 99% of
> batteries are rated at the 20 hour discharge rate.
>
> If we now try the same experiment with the corrected
> version of the
> equation:-
>
> T = C/(I/(C/R))^n X (R/C)
>
> We get:-
>
> T = 100/(5/(100/20))^n X (20/100)
> T = 100/(5/5)^n X (0.2)
> T = 100/1 X (0.2)
> T = 100 X 0.2
> T = 20 hours, which we know to be correct.
>
> We also know that doubling this discharge current
> should result in a bit
> less than half the time available. We know that much
> to be certain, due
> to Peukert's effect. Doubling the discharge current
> to 10 amps should
> result in a bit less than 10 hours available run
> time.
>
> So let's now try that calculation to convince us
> that our version of the
> equation does indeed work correctly.
>
> T = C/(I/(C/R))^n X (R/C)
> T = 100/(10/(100/20))^n X (20/100)
> T = 100/(10/5)^n X 0.2
> T = 100/(2)^n X 0.2
> T = 100/2.46 X 0.2
> T = 40.6 X 0.2 = 8.1 hours
>
> Now that's more like it.
>
> It is a mystery to us how magazine articles have
> been written using the
> incorrect application of the equation. Also, the
> internet is full of
> websites showing their author's expertise on all
> matter's Peukert, yet
> quoting this incorrect usage of the equation.
>
> The calculations are self contradictory when trying
> to use it and simply
> do not work.
>
> The only rational explanation we can think of is
> that people see the
> formula, assume it to be correct, never actually try
> to use it, and
> therefore never realise that it's actually wrong.
> This even seems to be
> the case with magazine articles, battery monitor
> owners manuals and
> several internet sites. It seems they haven't
> actually checked their
> results against reality and just assume the
> calculated figures are
> correct. But they do so enjoy showing their
> expertise and quoting the
> equation, even though they clearly don't understand
> it. No other
> explanation seems feasable.
>
> One last point about the use of Peukert's equation.
> You may occasionally
> see the equation written as T = Ca/I^n or in some
> other order but with
> an extra figure in there somewhere (the "a" in this
> example). This extra
> figure is usually specified as being an empirically
> derived factor,
> usually with no explanation as to what it is for. We
> will call this
> equation the fudged equation.
>
> It is actually an attempt to modify the formula so
> that it works given a
> certain battery capacity and hour rating. However
> the figure has to be
> arrived at by trial and error by trying a
> calculation, and adjusting
> this figure until the 20 hour calculation comes out
> correct. It's not
> very elegant involving a lot of guesswork.
> Especially as the required
> figure can actually be calculated from the given
> data!
>
> The corrected version of the equation that we used
> above was kept in
> that fashion because it is easy to work with for the
> examples above.
> However, anyone with even a basic understanding of
> simple sums will
> instantly spot that the equation can be rewritten
> either as T =
> C(C/R)^n-1 /I^n or as T=R(C/R)^n /I^n (they are
> mathematically the
> same). I consider this to be slightly more elegant
> but slightly more
> complicated to work with for manual calculations.
> It's exactly the same
> as the one worked through in the above examples but
> rearranged.
>
> And those of you who are still awake will have
> spotted that the
> (C/R)^n-1 the first of these two equations replaces
> the "a" in the
> fudged equation. As I said, it seems odd to add an
> empirically derived
> figure when it can be calculated from the given
> data.
>
> Finally, you may also, on certain websites or in
> certain articles, see
> it written as T = C/(Ia)^n . Where "a" is, again, an
> empirically derived
> figure. This is a similar attempt to the fudged
> equation mentioned
> above, and again, the empirically derived figure is
> guessed at until the
> 20 hour calculation comes out correct. However in
> this case, the
> emprically derived figure is in the wrong place in
> the equation and the
> other results will be highly inaccurate.
>
> Now, you've just seen how much less run time than 10
> hours is actually
> available when a 100 amp hour battery is discharged
> at 10 amps. About
> 17% less than a quick "amps X time" calculation
> would show. At higher
> discharge rates the effect becomes very large
> indeed.
>
> An often neglected aspect of Peukert's effect is
> that discharging at
> lower rates will increase the run time quite
> substantially. For
> instance, in our example of a 100 amp hour battery
> (at the 20 hour
> rate), with a Peukert's exponent of 1.3, discharging
> the battery at 5
> amps gives us 20 hours run time (so 100 amp hours
> are actually
> available). Discharging at 2 amps gives us 66 hours
> run time. But wait,
> that's 2 amps for 66 hours, that means the battery
> has provided 132 amp
> hours. This is correct. At lower discharge rates,
> Peukert's effect means
> the battery has a higher capacity. This is why it is
> so important to
> check the rating on battery specifications. Rating
> this same battery at
> the 100 hour discharge rate (instead of the more
> usual 20 hour rate)
> would result in a higher amp hours "number" to stamp
> on the side of the
> battery, thus making the battery *look* bigger than
> it really is. The
> true capacity is exactly the same.
>
> Discharging this same battery at 0.5 amps would give
> a total run time of
> just under 400 hours. That means a total of 200 amp
> hours were provided
> by the battery.
>
> *Important note*
>
> As described above, as the current approaches very
> low levels the total
> available amp hours seems to increase beyond the
> capacity of the
> battery. This is quite correct and the effect will
> be seen graphically
> later in this article. However, balanced against
> this is the self
> discharge of the battery which goes some way to
> cancelling this effect
> at very low discharge currents. The final effect is
> that, at very low
> discharge rates, the apparent total amp hours
> available from the battery
> is never quite as high as a calculation based purely
> on Peukert's effect
> would indicate. Some people incorrectly come to the
> conclusion that
> Peukert's Equation does not operate correctly at
> very low discharge
> rates. This is not the case. Peukert's Equation
> *does* work correctly at
> *all* discharge rates. It just seems like it doesn't
> unless the battery
> internal self drain is taken into consideration.
>
> By way of example, Discharging the 100 amp hour
> battery at 0.5 amps (as
> shown above) results in a run time of just under 400
> hours. That is 16
> days and during that time a typical deep cycle wet
> cell battery could
> well have self discharged by around 15 to 20 amp
> hours or so thus making
> it *look* like Peukert's Equation did not operate
> correctly..
>
> Now, whilst these figures are interesting, and quite
> illuminating to the
> uninitiated, actually calculating them is incredibly
> boring. To sit
> there with a calculator, running through the
> equation with different
> figures is tedious to say the least. So........
>
> Being the lovely people that we are.......
>
> We have written you a simple Peukert calculator in
> Microsoft Excel
> format and put it on this website. This will enable
> you to play to your
> heart's desire. This calculator uses the exact same
> equation shown above
> but rearranged to a more elegant format. You can
> download it by right
> clicking here
> <http://www.smartgauge.co.uk/calcs/peukert.xls> and
> selecting "save target as" or use the link on the
> left hand side.
>
> This calculator will allow you to enter the battery
> capacity, the
> capacity rating (i.e. 20 hour rating, 100 hour
> rating etc) and Peukert's
> exponent for the battery type. It will then
> calculate a range of
> discharge currents from very low up to a discharge
> equivalent to the
> battery capacity. It then displays what is termed
> the "peukert corrected
> amps" (which is the equivalent discharge rate such a
> load will remove
> from that particular battery) for each discharge
> current and the
> available run time, again for each discharge current
> (note that the time
> is shown in hours as a decimal not in hours and
> minutes). Finally it
> shows the total amp hours available from the battery
> at each discharge
> rate.
>
> There is also a window to allow the user to enter
> any discharge current
> and it will calculate all the same values for that
> particular current.
>
> Finally, there is a graph on the page which shows
> the discharge current
> along the bottom, and the total available amp hours
> up the left hand side.
>
> Typical Peukert exponents vary widely between
> different manufacturers
> but an average figure for a true deep cycle battery
> is about 1.3. For
> AGMs about 1.10 and for hybrids about 1.15. Have a
> play. You will be
> surprised at just how much difference a heavy
> discharge rate makes to
> the available run time. And perhaps also surprised
> at just how many amp
> hours are available from a battery when the
> discharge rate is very low.
>
> There is a much more detailed explanation of
> Peukert's Equation here
> <http://www.smartgauge.co.uk/peukert_depth.html>
> along with a
> mathematical explanation and proof of how any why
> our modifed equation
> works correctly for a given battery capacity
> specification. This
> equation is then developed further to produce one
> that will allow
> Peukert's exponent to be calculated from a battery
> data sheet when this
> information is not available. The maths is somewhat
> involved.
>
>
>
>
> Web site and all contents Copyright SmartGauge
> Electronics 2005, 2006,
> 2007. All rights reserved.
> Page last updated 13/01/2007
>
>
>
> elle wrote:
> > Bill,
> >
> > You are right, I have not used the R-22...but I am
> > familiar with solar panels & have had to calculate
> > drain on the three other boats we have owned that
> > also had their own unique configurations of
> batteries,
> > chargers, toys, etc etc.
> >
> > I'm not interested in !Quien es mas macho!...just
> > stick to the conversation & don't feel you have to
> > beat everyone down. We know you're smart...some
> others
> > on the list might be sorta smart, too....
> >
> > Why not publish your 'findings' as to each toy you
> > have aboard and its consumption. That's easy enugh
> to
> > do if you can read a meter. And it is not a
> function
> > of which type of battery you are currently using.
> >
> > Now THAT'S news we can use!
> >
> > BTW Bill..the name is elle.
> >
> >
> >
> > BTW..Joe..after doing some research, it appears
> that
> > our hard solar panels may actually output more
> than
> > posted previously...the hard ones output more than
> the
> > flexible ones.
> >
> >
> > elle
> >
> >
> >
> >
> > --- Bill Effros <bill at effros.com> wrote:
> >
> >
> >> L.
> >>
> >> I am not making those assumptions, you are
> making
> >> those inferences.
> >>
> >> I have owned an R-22 for 10 years. Every day I
> have
> >> been on board--well
> >> over 500--I have noted the electrical
> consumption.
> >> I have hooked up
> >> single batteries and dual batteries. I have used
> >> flooded, gel, and
> >> AGM. I have used motors with and without
> >> alternators. I have used
> >> solar panels, and I have covered them. I know
> what
> >> I am talking about
> >> from experience.
> >>
> >> You have not yet used your boat. You are using
> >> tables and graphs that
> >> are wrong for the boats for which they are
> >> written--and are even more
> >> wrong for R-22s with Solar Panels.
> >>
> >> I have purchased additional Folding Solar Panels
> >> which I now use to
> >> recharge all the appliance batteries on board. I
> >> recharge all radios,
> >> flashlights, cd players, etc -- including my VHF
> >> radio using solar
> >> power. I run a laptop off my batteries. I run
> my
> >> cell phone off the
> >> house batteries.
> >>
> >> My boat has never needed to be recharged from
> house
> >> current. It is on a
> >> mooring all summer and in a boatyard all winter.
> I
> >> never remove the
> >> batteries from the boat even though I live near
> NYC.
> >> I could not do
> >> that without the solar charger, since the motor
> does
> >> not run all
> >> winter. My boat batteries have never even come
> >> close to being fully
> >> discharged.
> >>
> >> I accidentally shorted one of my batteries one
> year.
> >> It did not short
> >> out the other, even though the 2 batteries were
> >> connected in parallel.
> >> When I realized what had happened, I disconnected
> >> the bad battery and
> >> just used a single battery for the rest of the
> >> summer. I never got
> >> close to discharging the one, not as good as it
> used
> >> to be, battery.
> >>
> >> I am in the process of changing over all of my
> >> lights to LEDs. I
> >> suspect that I could leave the LEDs on 24/7 and
> that
> >> my batteries would
> >> never run down with the solar cells on them. But
> I
> >> haven't tested that
> >> theory yet.
> >>
> >> Bill Effros
> >>
> >> elle wrote:
> >>
> >>> Bill,
> >>>
> >>> You are making two assumptions:
> >>> . that the R-22's have LED's rather than the
> >>>
> >> installed
> >>
> >>> incandescent lights; and
> >>> 2) that the engine battery is 2a) the only
> >>>
> >> battery,
> >>
> >>> and 2b) that it is b=connected to the house
> >>>
> >> lights.
> >>
> >>> NOT!
> >>>
> >>> Each may be very different from what i
> described.
> >>>
> >> I
> >>
> >>> based my comments on my own configuration.
> >>>
> >>> Your mileage may vary.
> >>>
> >>> elle
> >>>
> >>>
> >>>
> >>> --- Bill Effros <bill at effros.com> wrote:
> >>>
> >>>
> >>>
> >>>> Hadz,
> >>>>
> >>>> Power consumption meters will do all the
> >>>> calculations for you. While
> >>>> they are expensive, they answer a lot of
> >>>>
> >> questions,
> >>
> >>>> and bring peace of
> >>>> mind. They will ultimately save you a lot of
> >>>>
> >> money.
> >>
> >>>> Solar panels actually do bring a lot to the
> >>>>
> >> party.
> >>
> >>>> The consumption
> >>>> figures L. and Art are using--which you will
> see
> >>>> widely used
> >>>> elsewhere--are incorrect in real life.
> >>>>
> >>>> The starter motors on large boats draw far more
> >>>> electricity out of
> >>>> batteries than an equivalent number of LEDs
> left
> >>>> burning for the same
> >>>> calculated number of Amp-Hours.
> >>>>
> >>>> On our boats, motors with starters will put
> more
> >>>> electricity back into
> >>>> the battery than they consume. Solar cells are
> >>>>
> >> all
> >>
> >>>> that are required to
> >>>> put electricity back into the batteries for
> >>>>
> >> lights,
> >>
> >>>> stereos, and other
> >>>> incidental uses. When you are cruising you
> will
> >>>> inevitably wind up
> >>>> using your motor a lot. This will provide
> plenty
> >>>>
> >> of
> >>
> >>>> electricity for
> >>>> auto-pilots and lights. Should the battery
> fail,
> >>>> all you need to do is
> >>>> pull the cord on our little motors to start
> >>>> them--you can't do that with
> >>>> big boats which is why they factor in so much
> for
> >>>> idiots--the running
> >>>> motor will provide the electricity you need for
> >>>> lights/autopilot/and
> >>>> bringing the batteries back up to fully charged
> >>>> levels.
> >>>>
> >>>> One battery is all you really need on our boats
> >>>> almost all of the time.
> >>>> 2 batteries are over-kill. Top them off with
> >>>>
> >> solar
> >>
> >>>> panels most of the
> >>>> time. Get an electric starting motor. Your
> >>>> batteries should never run
> >>>> down if they are constantly topped off by solar
> >>>> panels. Properly
> >>>> maintained batteries that are never fully
> >>>>
> >> discharged
> >>
> >>>> will last for more
> >>>> than 6 years.
> >>>>
> >>>> Bill Effros
> >>>>
> >>>> Joseph Hadzima wrote:
> >>>>
> >>>>
> >>>>> Thanks elle & Art!
> >>>>>
> >>>>> I had assumed the pannel utilitiy was related
> >>>>>
> >> both
> >>
> >>>>>
> >>>>>
> >>>> to
> >>>>
> >>>>
> >>>>> consumpson, and latitude; and since you're
> also
> >>>>>
> >>>>>
> >>>> just above
> >>>>
> >>>>
> >>>>> the 37th latitude, I appreciate your
> >>>>>
> >> calculations.
> >>
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>>> --- "Arthur H. Czerwonky"
> >>>>>
> >>>>>
> >>>> <czerwonky at earthlink.net> wrote:
> >>>>
> >>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>> Elle,
> >>>>>>
> >>>>>> Excellent perspective on the panels. They
> >>>>>>
> >> don't
> >>
> >>>>>>
> >>>>>>
> >>>> bring
> >>>>
> >>>>
> >>>>>> much to the party. I bought one of the LED
> >>>>>>
> >>>>>>
> >>>> utility
> >>>>
> >>>>
> >>>>>> lights from Boaters World at the Annapolis -
> >>>>>>
> >> not
> >>
> >>>>>>
> >>>>>>
> >>>> bad at
> >>>>
> >>>>
> >>>>>> all, and low power consumption. I bought LED
> >>>>>>
> >>>>>>
> >>>> Xmas lights
> >>>>
> >>>>
> >>>>>> before the holidays, for next year's boat
> >>>>>>
> >> parade
> >>
> >>>>>>
> >>>>>>
> >>>> in
> >>>>
> >>>>
> >>>>>> Savannah possibly. Five strings powered thru
> a
> >>>>>>
> >>>>>>
> >>>> 70 watt
> >>>>
> >>>>
> >>>>>> inverter (the lights were a/c because the DC
> >>>>>>
> >> were
> >>
> >>>>>>
> >>>>>>
> >>>> sold
> >>>>
> >>>>
> >>>>>> out) were no problem at all, plenty for 80'
> of
> >>>>>>
> >>>>>>
> >>>> big LED
> >>>>
> >>>>
> >>>>>> bulbs. The mfg will not comment on amp draw,
> >>>>>>
> >> but
> >>
> >>>>>>
> >>>>>>
> >>>> it must
> >>>>
> >>>>
> >>>>>> be minescule.
> >>>>>>
> >>>>>> I really think the stability questions about
> >>>>>>
> >> the
> >>
> >>>>>>
> >>>>>>
> >>>> Rhodes
> >>>>
> >>>>
> >>>>>> have been overdone, therefore of concern to
> >>>>>>
> >> you,
> >>
> >>>>>>
> >>>>>>
> >>>> Hadz,
> >>>>
> >>>>
> >>>>>> and others. Each of us skipper has our own
> >>>>>>
> >>>>>>
> >>>> comfort
> >>>>
> >>>>
> >>>>>> boundaries, and this remarkable craft has the
> >>>>>>
> >>>>>>
> >>>> ability to
> >>>>
> >>>>
> >>>>>> adjust accordingly. If you find the boat
> >>>>>>
> >>>>>>
> >>>> sensitive to
> >>>>
> >>>>
> >>>>>> particular winds, it is so simple to trim
> >>>>>>
> >> either
> >>
> >>>>>>
> >>>>>>
> >>>> main or
> >>>>
> >>>>
> >>>>>> genny. Bill likes to stay level on the water
> >>>>>>
> >> in
> >>
> >>>>>>
> >>>>>>
> >>>> the LI
> >>>>
> >>>>
> >>>>>> area, even with the ability to steer with
> >>>>>>
> >> weight
> >>
> >>>>>> distribution. Match that...
> >>>>>>
> >>>>>> I really don't think there is a boat to
> compare
> >>>>>>
> >>>>>>
> >>>> with
> >>>>
> >>>>
> >>>>>> our's in any catagory except maybe
> competitive
> >>>>>>
> >>>>>>
> >>>> racing
> >>>>
> >>>>
> >>>>>> with IMF.
> >>>>>>
> >>>>>> I can't wait to read your first postings
> after
> >>>>>>
> >>>>>>
> >>>> you
> >>>>
> >>>>
> >>>>>> receive yours. We will hear the Oh's! and
> Ah's
> >>>>>>
> >>>>>>
> >>>> in
> >>>>
> >>>>
> >>>>>> Atlanta, at Hartwell, and at Edenton without
> >>>>>>
> >>>>>>
> >>>> fail! I can
> >>>>
> >>>>
> >>>>>> bet you're ready to get underway. If you are
> a
> >>>>>>
> >>>>>>
> >>>> little
> >>>>
> >>>>
> >>>>>> short to see the bow, nary a problem because
> >>>>>>
> >> you
> >>
> >>>>>>
> >>>>>>
> >>>> will
> >>>>
> >>>>
> >>>>>> just levitate.
> >>>>>>
> >>>>>> Many cheers,
> >>>>>> Art
> >>>>>>
> >>>>>> -----Original Message-----
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>> From: elle <watermusic38 at yahoo.com>
> >>>>>>> Sent: Jan 27, 2007 12:41 PM
> >>>>>>> To: The Rhodes 22 mail list
> >>>>>>>
> >>>>>>>
> >>>> <rhodes22-list at rhodes22.org>
> >>>>
> >>>>
> >>>>>>> Subject: Re: [Rhodes22-list] speaking of
> solar
> >>>>>>>
> >>>>>>>
> >>>> panels
> >>>>
> >>>>
> >>>>>>> Hadz,
> >>>>>>>
> >>>>>>> Whether the solar panels can keep the
> >>>>>>>
> >> batteries
> >>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> charged is a function of the no. of amp
> hours
> >>>>>>
> >>>>>>
> >>>> used by
> >>>>
> >>>>
> >>>>>> the goodies below.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>
> >>>>>>> I don't have my estimated numbers with me
> >>>>>>>
> >> (I'm
> >>
> >>>>>>>
> >>>>>>>
> >>>> at the
> >>>>
> >>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> marina working...!) but, for example, if you
> >>>>>>
> >> have
> >>
> >>>>>>
> >>>>>>
> >>>> 5
> >>>>
> >>>>
> >>>>>> interior lights below and if each interior
> >>>>>>
> >> light
> >>
> >>>>>>
> >>>>>>
> >>>> pulls
> >>>>
> >>>>
> >>>>>> 1.5 amps/hr , you are using 7.5 amps per hour
> >>>>>>
> >>>>>>
> >>>> using all
> >>>>
> >>>>
> >>>>>> lights. Or you could use 1 light for 7.5
> hours.
> >>>>>>
> >>>>>>
> >>>> The solar
> >>>>
> >>>>
> >>>>>> panels may provide approx. 1-2 amp hrs/day
> each
> >>>>>>
> >>>>>>
> >>>> in this
> >>>>
> >>>>
> >>>>>> latitude (maybe a bit more when the days are
> >>>>>>
> >>>>>>
> >>>> longer &
> >>>>
> >>>>
> >>>>>> fewer when the days become shorter)...so
> >>>>>>
> >>>>>>
> >>>> estimating
> >>>>
> >>>>
> >>>>>> usage, and the knowing the % you can draw
> your
> >>>>>>
> >>>>>>
> >>>> batteries
> >>>>
> >>>>
> >>>>>> down, I'd say don't count on the solar panels
> >>>>>>
> >>>>>>
> >>>> doing more
> >>>>
> >>>>
> >>>>>> than to top 'em off.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>
> >>>>>>> When I did some estimates the other day, I
> >>>>>>>
> >>>>>>>
> >>>> figured I
> >>>>
> >>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> could stay out 2-3 days (if sunny), bieng
> >>>>>>
> >>>>>>
> >>>> conservative in
> >>>>
> >>>>
> >>>>>> use, and have to go in to recharge from shore
> >>>>>>
> >>>>>>
> >>>> power on
> >>>>
> >>>>
> >>>>>> the 3rd day...more or less.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>
> >>>>>>> elle
> >>>>>>>
> >>>>>>>
> >>>>>>> Joseph Hadzima <josef508 at yahoo.com> wrote:
> >>>>>>>
> >>>>>>> I was under the impression that solar panels
> >>>>>>>
> >>>>>>>
> >>>> worked best
> >>>>
> >>>>
> >>>>>>> when they are set 90 degrees to the Sun.
> With
> >>>>>>>
> >>>>>>>
> >>>> the panels
> >>>>
> >>>>
> >>>>>>> statically mounted on the Rhodes, are they
> >>>>>>>
> >>>>>>>
> >>>> sufficient at
> >>>>
> >>>>
> >>>>>>> keeping the batteries charged during a
> typical
> >>>>>>>
> >>>>>>>
> >>>> weekend
> >>>>
> >>>>
> >>>>>>> cruise, or are they more for: charging when
> >>>>>>>
> >> you
> >>
> >>>>>>>
> >>>>>>>
> >>>> leave
> >>>>
> >>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> your
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>> boat tied at a mooring / slip during the
> week
> >>>>>>>
> >>>>>>>
> >>>> and sail
> >>>>
> >>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> on
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>> the weekend?
> >>>>>>>
> >>>>>>> I assume the latitude where you sail may
> >>>>>>>
> >> affect
> >>
> >>>>>>>
> >>>>>>>
> >>>> the
> >>>>
> >>>>
> >>>>>>> efficiency.
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>> HADZ (a.k.a. joe)
> >>>>>
> >>>>> "That's what a ship is, you know. It's not
> just
> >>>>>
> >> a
> >>
> >>>>>
> >>>>>
> >>>> keel and hull and a deck and sails. That's what
> a
> >>>> ship needs. But what a ship is... is freedom."
> >>>>
> >>>>
> >>>>> -- Captain Jack Sparrow
> >>>>>
> >>>>>
> >>
> __________________________________________________
> >>
> >>>>> Use Rhodes22-list at rhodes22.org, Help?
> >>>>>
> >>>>>
> >>>> www.rhodes22.org/list
> >>>>
> >>>>
> >>>>>
> >>>>>
> >>>>>
> >>
> __________________________________________________
> >>
> >>>> Use Rhodes22-list at rhodes22.org, Help?
> >>>> www.rhodes22.org/list
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >>>
> >
>
____________________________________________________________________________________
> >
> >>> The fish are biting.
> >>> Get more visitors on your site using Yahoo!
> Search
> >>>
> >> Marketing.
> >>
> >
>
http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php
> >
> >>>
> __________________________________________________
> >>> Use Rhodes22-list at rhodes22.org, Help?
> >>>
> >> www.rhodes22.org/list
> >>
> >>>
> >>>
> >>
> __________________________________________________
> >> Use Rhodes22-list at rhodes22.org, Help?
> >> www.rhodes22.org/list
> >>
> >>
> >
> >
> >
> >
> >
>
____________________________________________________________________________________
> > Looking for earth-friendly autos?
> > Browse Top Cars by "Green Rating" at Yahoo! Autos'
> Green Center.
> > http://autos.yahoo.com/green_center/
> > __________________________________________________
> > Use Rhodes22-list at rhodes22.org, Help?
> www.rhodes22.org/list
> >
> >
> __________________________________________________
> Use Rhodes22-list at rhodes22.org, Help?
> www.rhodes22.org/list
>
____________________________________________________________________________________
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